# What upgrades will lighten up the TTRS



## Williamttrs (Mar 29, 2013)

I am wondering what can be done to the TTRS in terms of upgrading and lightening at the same time. Please comment on my thoughts and elaborate on the reasons why you have your opinion.

Below are mostly guesses on my part. Please correct anything that is off base.

1. New brake system - save about 40 lbs in unsprung weight
2. New Wheels (aluminum?) - save up to 80 lbs in unsprung weight
3. Upgraded intercooler - save ? lbs.
4. Suspension? what? how much savings
5. Exhaust?
6. What else?

Anyone know why Audi went with a cast iron block instead of an aluminum block?


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## JohnLZ7W (Nov 23, 2003)

Brakes, wheels, tires, exhaust, seats.

You can probably save around 40lbs on wheels, maybe 12lbs on tires, another 10 on brakes and maybe 10-20 on exhaust if you go with the Scorpion titanium setup.

Pull the rear seats would maybe be another 30lbs and replace the front seats with lightweight shells and that might be worth as much as 80lbs.

Intercoolers are all larger and probably heavier. Not sure how much the magride setup weighs, you might be able to save a few pounds there too. H&R does a lightweight aluminum bodied coilover.

And I would guess they went with an iron block, vermicular graphite at that, for strength. That's why people are about to run such insane levels of torque with this engine. It's a beast.


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## Williamttrs (Mar 29, 2013)

I was under the impression that pound for pound aluminum was a stronger material than iron. In the 90's I seem to remember there was a lot of talk about engines getting aluminum heads and then aluminum blocks. During that time I kept up with the Camaro/Vette engines. Is this not the case? 

Perhaps a aluminum block is necessarily larger to achieve the same strength and there is not enough space in the engine compartment for a larger engine. It is pretty tight in there! Just a guess though.


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## primetime21 (Feb 14, 2013)

My .02

1. New brake system - save about 40 lbs in unsprung weight - No way will you save 40lbs... On my B8 S4 I went from the stock fronts to a Brembo setup and cut 8lbs per side and it wasn't all rotating mass since the caliper is stationary... The RS brakes are already lighter and bigger so unless you go to a smaller size I would say mayb 5-8lbs per wheel... Again, on my B8 S4 I dropped about 5.7lbs per wheel by going with the JHM LW rotors... 
2. New Wheels (aluminum?) - save up to 80 lbs in unsprung weight - Probably your best route is wheels and tires... Don't have my car yet(p/u week of Apri 29th), so I can't say for sure but I bet they are in the 55-60lbs range per wheel and I know you can get some killer forged wheels with tires that will be 40-45lbs... I plan to go with the OZ superforgiatas...
3. Upgraded intercooler - save ? lbs. - This will most likely be bigger and heavier but the lower and more consistent IAT's are worth it...
4. Suspension? what? how much savings - No clue...
5. Exhaust? - Loosing the cats and a lighter material exhaust would probably drop 20-30lbs but it's not rotating mass... 
6. What else? - LW battery, carbon fiber body panels if anyone makes them, removal of rear seats, drive around with 1/4 tank or less, remove all misc stuff from the car, etc. Probably a few other things but it will start to get costly... I just can't wait to get the car and start modding


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## MSS Automotive (Mar 20, 2013)

Well another opportunity for me to comment as I have seen all of these things come and go and even seen people who went lightweight initially come back to putting things back to how Audi made it...so in my view unless you are going racing at weekends for trophies there is not much point reducing weight...just my view based on noting others who reduced weight yet ended with slower lap or drag times.

Here goes some views though...;
1) *Brakes*...we weighed OEM at 17.5kg per corner fronts and I reckon the rears are 10kg (estimated MAX) per corner. To get lighter, which you can, you will need aftermarket - budget £1.5k discs and pads changeover per corner or £3k for a solution which will also include caliper change. Look to save 3kg MAX per corner.

2) *Wheels *– you can save as much weight as you wish to spend…I once worked it out to be a cost of £250 per KG saved per corner. Do the math and you will find a manufacturer – I like HRE if I went non-OEM – and they will happily help you out. I have seen very light weight wheels however I have also read that for the weight of our cars…going that light on wheels means they may be prone to breakage when you hit something tough – doesn’t everything?

3) *IC *- Some actually add weight and others don’t. I will look at the V2 Wagner which incorporates the crash bar. Am informed these are the lightest out there and perform very well…apparently. I have Pro-Alloy and am happy with it…been in place since 2010 and does what I wanted it to do.

4) *Suspension *- Ahh, my favorite mod by far – If you are out winning trophies at the weekends then get bespoke build…else IMHO there are options out there including my own kit. Spend more get more features. If you want to keep MagneRide though then my kit makes a strong case indeed.

5) *Exhaust *- Hmmm, keep it OEM…or buy what sounds good to you. I will not pay too much attention on the weight saving stuff – the weight saved is on the wrong end…rears…where you actually need more weight…!

6) Lightweight battery however as with #5 it is at the wrong end. Removal of internal parts like seats; fitting carbon fibre doors and bonnet. All these helps reduce weight though as I say, you want to focuses on reducing the weight from the front not the rears. If anything, leave the rears as it is and focus on the fronts or add more power and get a better handling car.

Think Nissan GT-R…weighs almost 2-ton yet with about 600-BHP it hides that weight very well hence am not sold on weight saving unless am in with a chance of winning trophies every weekend.


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## R5T (Apr 7, 2010)

The TT RS engine weighs 185 Kg, that is more then the old 3.2 V6 (VR6) engine used in the TT.
And it's more then most V8's, therefore it can be called a heavy pig. 
An 2.0TFSI TT quattro with 340 hp will perform better then the TT RS with 340 hp, or both with 400 hp for that matter.


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## carl44 (Nov 23, 2012)

The stock wheels weigh 30lbs. I got a set of Enkei PF01 18x8 45et I use a 3 mm spacer and they clear the brakes plus cut 48lbs of unsprung weight. A difference you can feel not like cutting dead weight . Carl


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## smack_ttrs (Mar 24, 2013)

is this for track or street? 
brakes aren't going to save much either way but the benefit on bearings going to an aluminum hat for a track car is nice. a bit of unsprung weight advantage but not as much as a wheel from a rotational standpoint since the savings is so close to the center of rotation.

william is spot on about this stuff.
wheel weight? how big of a checkbook do you have? forged is obviously the way to go. yes there are some light cast wheels but bang them off a few good sized curbs supporting a 3200lbs car and you may have some issues. for the street i'm sure the cast ones will hold up fairly well. although i did have a cast advan rs on my evo get a couple cracks in the barrel after 20k of street driving with the standard occasional pothole.

for weight it's hard to beat the wagner ic since it's the only tube/fin product out there right now. everything else is bar/plate which is a fair bit heavier. although there might be some mass vs. cooling efficiency math involved that could probably get this a bit closer.

any alum body coilovers are always going to drop weight over the stock steel body setup. although you're give up variable ride comfort for it.

for exhaust it's pretty much a wash until akrapovic make a ti version. but their's usually work out to a ballpark of about 10% of the vehicle cost. (gt3rs-12k/evo-3.5k) sure you'll gain a bit from losing cats and going to a single 3" instead of the dual 2.25" or whatever but there's no gain like going to ti. just be ready for the noise if you do. they make a hell of a racket haha.

also agree with william on dumping weight in the tail of the car. for straight line accel and braking sure but for actual balance you're probably making things worse. getting data acq and doing laps is the only way to tell for sure though.

just my random .02


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## Williamttrs (Mar 29, 2013)

Thanks for the interesting and informative discussion. To sum up what I think I am hearing.

1. As far as lightening up the car just for the sake of dropping an arbitrary number, there are many expensive things that can be done.

2. As far as lightening up the car for the sake of increased performance and overall balance, the only changes that might make sense have to do with unsprung weight and most probably the wheel/tires only.

3. If the overall goal is to increase various performance characteristics, there are many solutions that do not involve reducing weight and cost less.

On the surface it seems like reducing weight is a "safe" way of making everything about the car a little better, without changing the refinement of the car. However, this seems to be a naive position as the elegance is created from many factors being in harmony with each other. For me, the real challenge is to change several parts of the equation so that the proportions of each part of the equation stay the same.


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## NamJa (Jul 31, 2012)

Eat more fruits and veggies, cut out beer and ice cream. That'll probably be good for 10-20 lbs:laugh:


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## MSS Automotive (Mar 20, 2013)

Williamttrs said:


> Thanks for the interesting and informative discussion. To sum up what I think I am hearing.
> 
> 1. As far as lightening up the car just for the sake of dropping an arbitrary number, there are many expensive things that can be done.
> 
> ...


IMO, yep on #1 > 3.

For me the summary is also spot on...half of the difficulties is how to keep a lid on ‘DESIRE’. That is a strong thing when it comes to modding…though if we were to keep a lid on our ‘DESIRE’, chances are that we will then all be driving around in a Ford Model T – in black offcourse…!!!


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## MoreGooderTT (Aug 20, 2011)

Light weight wheels are a mod that I enthusiastically recommend. I also recon that my shorter stopping distance is an added safety bonus that I can use to rationalize my mod dollars.


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## [email protected] (Sep 28, 2004)

Wheels. Drop to an 18x10.5 wheel for a low MOI relative to the OEM 19" wheel, ~19.5 lbs 
Tires. Go to a 285/30/18... again low MOI relative to grip advantage. ~27 lbs 
Suspension. Monotube shocks might save a few pounds over the stock stuff. Could use Ti springs. 
Brakes - stock brakes are already pretty light... maybe a wider vane rotor F&R. 
Exhaust - Titanium as stated before ~ 11 lbs 
Carbon trunk, carbon wing, Carbon hood. 8lbs, 2lbs, 20lbs 
Aluminum Driveshaft - reduced by about 8lbs 
Lightweight twin disc clutch - reduced by about 20 pounds 
Lightweight crankshaft - reduce by about 10 pounds. 
Rifle drill front axles (if they aren't already hollow) 
Lower the seats in the car... run lighter seats 

Remove emissions devices... catalyst, evap canister, etc. Remove unnecessary equipment, shields, etc. probably -20lbs 

Aftermarket intercoolers will be heavier than the OEM unit and they should be. +10 pounds 

The TTRS uprights are beautiful. 

Does anyone have a 100% stock OEM corner balance of this car?


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## cipsony (Mar 26, 2013)

RTErnie said:


> Carbon trunk, carbon wing, Carbon hood. 8lbs, 2lbs, 20lbs
> Aluminum Driveshaft - reduced by about 8lbs
> Lightweight twin disc clutch - reduced by about 20 pounds
> Lightweight crankshaft - reduce by about 10 pounds.


 Can you give some more details about the weight of the parts listed (OEM and aftermarket) and where to source them? Did you do this on your car? 

Thx


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## [email protected] (Sep 28, 2004)

cipsony said:


> Can you give some more details about the weight of the parts listed (OEM and aftermarket) and where to source them? Did you do this on your car?
> 
> Thx


 Just my experience with lightening vehicles... having a rough idea what the OEM parts weigh and how much the carbon parts should weigh given their shape and size. I've done all this to my current vehicle (non-audi). But looking at a TTRS to replace my current car.


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## cipsony (Mar 26, 2013)

RTErnie said:


> Just my experience with lightening vehicles... having a rough idea what the OEM parts weigh and how much the carbon parts should weigh given their shape and size. I've done all this to my current vehicle (non-audi). But looking at a TTRS to replace my current car.


 Well, with the TT don't expect to remove weight easily as this was done by Audi already. 
Aluminium hood & chassis, aluminium everywhere (except the doors and rear hatch), pretty light drive-shaft. Many aftermarket parts are heavier than the OEM ones.


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## [email protected] (Sep 28, 2004)

cipsony said:


> Well, with the TT don't expect to remove weight easily as this was done by Audi already.
> Aluminium hood & chassis, aluminium everywhere (except the doors and rear hatch), pretty light drive-shaft. Many aftermarket parts are heavier than the OEM ones.


 Carbon is way lighter than aluminum for superficial body parts (specific modulus of carbon is off the charts better than aluminum. My car came originally with an aluminum hood... and a Magnesium valve cover. Doesn't mean the car can't be lighter.


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## carl44 (Nov 23, 2012)

carl44 said:


> The stock wheels weigh 30lbs. I got a set of Enkei PF01 18x8 45et I use a 3 mm spacer and they clear the brakes plus cut 48lbs of unsprung weight. A difference you can feel not like cutting dead weight . Carl


 Email me if you want them ill save you $1000..I have custom forged set coming. [email protected]


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## Williamttrs (Mar 29, 2013)

carl44 said:


> Email me if you want them ill save you $1000..I have custom forged set coming. [email protected]


 pics please. I intend to get new wheels, but am going to wait for just what I am looking for, which by the way I don't know what that is right now.


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## Williamttrs (Mar 29, 2013)

A carbon hood sounds interesting. I am guessing $1K plus paint and install. That would be a lot for just 20lbs. 

I also figure that I will burn up my clutch sometime between now and the end of the year. That will be the ideal time to get a better one and lighter if possible.


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## [email protected] (Sep 28, 2004)

Williamttrs said:


> A carbon hood sounds interesting. I am guessing $1K plus paint and install. That would be a lot for just 20lbs.
> 
> I also figure that I will burn up my clutch sometime between now and the end of the year. That will be the ideal time to get a better one and lighter if possible.


 I suspect a nice clutch option will be available soon that will be very streetable. Carbon hood will yes... be quite expensive to make. I'm not saying the Carbon hood would save 20 pounds. More likely closer to 10 pounds... just depends on how much the OEM hood weighs. It's also weight that is relatively high compared to the CoG. It's weight on the front tires (reduces front grip) 

I think this thread moves into a new level of importance for the community by weighing OEM components and the aftermarket components. Also posting actual corner balance weights... and any weight that has been removed.


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## myquitacre (Feb 17, 2013)

look into lightweight battery (I run a Braille 21lbs in my Nismo) and tires...the Michelin Pilot SuperSports are pretty lightweight.


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## J662 (Dec 8, 2011)

Cardio


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## dogdrive (Oct 19, 2005)

Interested to see which weight reduction stuff that OP chooses to do :thumbup::thumbup:


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## R5T (Apr 7, 2010)

myquitacre said:


> look into lightweight battery (I run a Braille 21lbs in my Nismo) and tires...the Michelin Pilot SuperSports are pretty lightweight.


 A lightweight battery is one thing you don't want to do. 
You take weight out at the wrong end of the car.  
The TT RS is already front heavy, taking out weight at the back make it worse.


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## Williamttrs (Mar 29, 2013)

dogdrive said:


> Interested to see which weight reduction stuff that OP chooses to do :thumbup::thumbup:


 Right now I am in the "go fast" stage. 

Tires, wheels and brakes will happen, but probably a little down the road. 

Suspension will likely happen after stage 2 APR or UM is finished... Hopefully I the next few weeks. Down pipe is on order. Should be 2 or 3 more weeks and APR needs to come through with the new tune or I will need to switch to UM.


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## [email protected] (Sep 28, 2004)

R5T said:


> A lightweight battery is one thing you don't want to do.
> You take weight out at the wrong end of the car.
> The TT RS is already front heavy, taking out weight at the back make it worse.


 I have a 4lb Lithium battery.. that I moved to the trunk  

I disagree on the taking weight out of the rear of the car comment.... less weight is always better. regardless of where it's located. It may not have the largest improvement on corner weights or CoG, but oh wells.


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## Williamttrs (Mar 29, 2013)

RTErnie said:


> I have a 4lb Lithium battery.. that I moved to the trunk
> 
> I disagree on the taking weight out of the rear of the car comment.... less weight is always better. regardless of where it's located. It may not have the largest improvement on corner weights or CoG, but oh wells.


 Tell us more about the 4 lb lithium battery. Where did you get it? How much? I thought the battery was already located in the truck?


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## [email protected] (Sep 28, 2004)

Williamttrs said:


> Tell us more about the 4 lb lithium battery. Where did you get it? How much? I thought the battery was already located in the truck?


 I don't have a TTRS at the moment.  Shorai lithium battery is about 350 dollars with charger...or you can get a Lithium Pro's which is about 700-1000 depending on the model you get. After killing one lithium battery... if I did it again I would get a larger battery than the common PC680 size lithium battery. There's not much compromise in terms of weight gain for additional CCA.


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## smack_ttrs (Mar 24, 2013)

i have a Shorai in the race evo. it seems nice but for some reason it's getting a charging error that i haven't had time to look into or call about. they are basically motorcycle batteries though. 
another one that works well is the carbon braille. that one is super light as well.


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## [email protected] (Apr 9, 2004)

Regarding carbon fiber hoods, I know of OSIR (stock look) or TID styling with a slightly Aston Martin look to it. These two mfrs are worth checking out and I have large galleries of each in our TT RS aftermarket photo gallery. 

http://fourtitude.com/galleries/?c=...)/TT RS/from 2006 (Type 8J)/Coupe/Aftermarket 

OSIR also does replacement chin, rear spoiler, and front fenders that are also vented with a vent style inspired by the original TTS Roadster concept car. 

I don't know weight differentials, but carbon is lighter than the aluminum or plastic that each piece would replace.


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## smack_ttrs (Mar 24, 2013)

the only problem with carbon panels is that it's tough to find good ones that aren't fiberglass backed and for looks only. 
on my evo the only one i could find that was actually lighter than the stock aluminum hood was dry carbon and ran me about 1500 at the time. amazingly light though. 
and that's a hell of a lot easier shape to make than the audi so i'd assume one for a tt would be twice that at least if you could convince someone to make it.


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## [email protected] (Apr 9, 2004)

smack_ttrs said:


> the only problem with carbon panels is that it's tough to find good ones that aren't fiberglass backed and for looks only.
> on my evo the only one i could find that was actually lighter than the stock aluminum hood was dry carbon and ran me about 1500 at the time. amazingly light though.
> and that's a hell of a lot easier shape to make than the audi so i'd assume one for a tt would be twice that at least if you could convince someone to make it.


 I have no clue about the construction behind the skin on either of the ones I'd mentioned.


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## [email protected] (Sep 28, 2004)

smack_ttrs said:


> the only problem with carbon panels is that it's tough to find good ones that aren't fiberglass backed and for looks only.
> on my evo the only one i could find that was actually lighter than the stock aluminum hood was dry carbon and ran me about 1500 at the time. amazingly light though.
> and that's a hell of a lot easier shape to make than the audi so i'd assume one for a tt would be twice that at least if you could convince someone to make it.


 The OSIR hoods... would be interesting to ask them if they could could use Epoxy Resin and either make it either via VARTM or Pre-preg with an autoclave. Not a wet lay poly with a fiberglass backing.


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## Williamttrs (Mar 29, 2013)

I would like to refocus on the drive train. 

Is there a stronger / lighter clutch available for the TTRS tranny? If so, about how much would it cost to purchase and install one. 

Are there other tranny parts that are worth swapping to save weight and increase strength / performance. 

Is there an aluminum crank and driveshaft available and what kind cost is there on these items? 

I am trying to cover all the bases here so that this thread can be a good reference in the future. 

Thanks to everyone who has contributed!


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## joneze93tsi (Aug 8, 2008)

Williamttrs said:


> Is there an aluminum crank


 :screwy:


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## cipsony (Mar 26, 2013)

Is there a stronger / lighter clutch available for the TTRS tranny? If so, about how much would it cost to purchase and install one. 

Sachs: plate and cover rated at more than the OEM --> I don't advise though 
SPEC: SM flywheel & plate & cover --> you should ask "Who would like to see the Audi TT RS raced?" on facebook about a feedback. I have my doubts about SPEC based on some reviews regarding other cars. 
HELIX: SM flywheel & plate & cover --> I am waiting for someone to install it and send a feedback (it will take some time) 
Loba: working on something 
Clutch Masters: If you send them the clutch assembly they will build whatever you want --> these guys provide some serious solutions so it might be a very good option in the end. 


Are there other tranny parts that are worth swapping to save weight and increase strength / performance. 

Will be soon but I can't tell right now. It is complicated to shave weight from this car while maintaining it's OEM aspect but it's doable. Fingers crossed I will come with a few solutions or maybe others will. 

Is there an aluminum crank and driveshaft available and what kind cost is there on these items? 

Aluminium driveshaft: would not hold unless the diameter will be bigger than the current one --> In this case it will not save much. 
CF driveshaft: I investigated this option: It can be made but it has to be similar construction to the OEM one (2 parts) otherwise it might vibrate + it has to have a larger diameter so it might go too close to the exhaust. 

I am trying to cover all the bases here so that this thread can be a good reference in the future.


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## smack_ttrs (Mar 24, 2013)

joneze93tsi said:


> :screwy:


 lol 
joneze, remember, no stupid questions. 

william, no way for an aluminum crank to hold up. they do make aluminum rods but not a long life type part. titanium rods would obviously hold up better but much more costly than a standard hi-end rod(gt3rs uses them for example) 

i think you're starting to confuse types of weight savings and why you would do it. 
anything you can pull off the motor(think rotating mass) will have more of an influence on the motor's characteristics than just removing 10 lbs from the car. like a lightweight flywheel vs. a 10lbs lighter battery. the battery will help a very small amount with accel,braking and handling. the flywheel however will actually change how quickly the motor revs as well as the normal benefits listed above. 

honestly wheels/tires are probably the easiest place to grab weight savings that has a large influence on handling. then a titanium exhaust and lithium battery. as you go towards the extreme the weight gets harder and more costly to find. also you can take your car from comfortable to annoying if you're not careful.


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## Williamttrs (Mar 29, 2013)

joneze93tsi said:


> :screwy:


 :thumbup: That is funny but you know we are all entitled to a brain fart at least once a day. Having said that, I think it is interesting to see the progress in alloy tech. I heard somthing on Modern Marvels a while back that said something like 60% of the alloys on cars today were not even invented a decade ago. In this same vain, it seems totatlly plausible that a light weight aluminum alloy could have have all the same qualities of a heavier steel component or other material. Who knows maybe there will be a carbon fiber drive shaft in another decade!


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## Williamttrs (Mar 29, 2013)

smack_ttrs said:


> lol
> joneze, remember, no stupid questions.
> 
> william, no way for an aluminum crank to hold up. they do make aluminum rods but not a long life type part. titanium rods would obviously hold up better but much more costly than a standard hi-end rod(gt3rs uses them for example)
> ...


 Yep these are good points and I think very helpful to the thread. Personally, when I start on this part of my play time, I intend to refer to this thread often. The principles of unsprung weight vs sprung weight and rotating mass and weight distribution are all helpful and important. 

Even a dumb question and a friendly "dig" can be instructive. Someone in the future may have a similar question.


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## Williamttrs (Mar 29, 2013)

cipsony said:


> Is there a stronger / lighter clutch available for the TTRS tranny? If so, about how much would it cost to purchase and install one.
> 
> Sachs: plate and cover rated at more than the OEM --> I don't advise though
> SPEC: SM flywheel & plate & cover --> you should ask "Who would like to see the Audi TT RS raced?" on facebook about a feedback. I have my doubts about SPEC based on some reviews regarding other cars.
> ...


 That is some really great info. Thank you!


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## smack_ttrs (Mar 24, 2013)

Williamttrs said:


> :thumbup: That is funny but you know we are all entitled to a brain fart at least once a day. Having said that, I think it is interesting to see the progress in alloy tech. I heard somthing on Modern Marvels a while back that said something like 60% of the alloys on cars today were not even invented a decade ago. In this same vain, it seem totatlly plausible that a light weight aluminum alloy could have have all the same qualities of a heavier steel component or other material. Who knows maybe there will be a carbon fiber drive shaft in another decade!


 the problem with bleeding edge tech is that it's prohibitively expensive. theoretically things are possible but not practical. and this is coming from someone that has a 130k+ into an evo lol 

want to save weight up front, have a aluminum, sleeved block made to swap with the cast iron one. 
that would save a bunch of weight exactly where you want to but a one off block would be off the charts expensive


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## Williamttrs (Mar 29, 2013)

smack_ttrs said:


> the problem with bleeding edge tech is that it's prohibitively expensive. theoretically things are possible but not practical. and this is coming from someone that has a 130k+ into an evo lol
> 
> want to save weight up front, have a aluminum, sleeved block made to swap with the cast iron one.
> that would save a bunch of weight exactly where you want to but a one off block would be off the charts expensive


 What if we do a group buy?


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## smack_ttrs (Mar 24, 2013)

Williamttrs said:


> That is some really great info. Thank you!


 i don't exactly agree with the driveshaft comments and the evo/subi platforms have the data to back it up. carbon driveshafts are definitely doable and have proven to hold up to much more torque that the ttrs is putting out. 2k for those on the above mentioned platforms. i know on the evo the aluminum driveshafts go from 3 piece down to two. saves around 18lbs or so if i recall correctly but about 5-6 of that was the fact that you lose a support bearing when going down to two piece. so 12ish lbs of rotational weight. 
both of these options are perfectly fine choices and are completely balanced and i know the aluminum versions have been run on very quick drag cars.


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## smack_ttrs (Mar 24, 2013)

Williamttrs said:


> What if we do a group buy?


 haha you could get all 1000 or however many owners are out there and it would still probably cost more than my drysump cosworth motor in the evo.


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## [email protected] (Sep 28, 2004)

I know an awesome clutch solution for the TTRS is coming. 

An aluminum driveshaft probably won't work because the OD will have to be larger, and there isn't really much more room for a large driveshaft. Carbon DS however... 

No aluminum crankshafts lol. 4340... yes. 5 pounds lighter than stock... yes possible. Stroker crank.... more than likely.


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## cipsony (Mar 26, 2013)

smack_ttrs said:


> i don't exactly agree with the driveshaft comments and the evo/subi platforms have the data to back it up. carbon driveshafts are definitely doable and have proven to hold up to much more torque that the ttrs is putting out. 2k for those on the above mentioned platforms. i know on the evo the aluminum driveshafts go from 3 piece down to two. saves around 18lbs or so if i recall correctly but about 5-6 of that was the fact that you lose a support bearing when going down to two piece. so 12ish lbs of rotational weight.
> both of these options are perfectly fine choices and are completely balanced and i know the aluminum versions have been run on very quick drag cars.


 What was the weight of the driveshaft of evo or subaru? 
Do you know what is the weight of the TT RS driveshaft? 
Do you know what is the equivalent diameter of a CF driveshaft vs the steel one that is supposed to replace? 
Do you know how much you can save with an aluminium driveshaft vs a steel one? 



On another note: Having a lighter driveshaft is not similar to having a ligher flywheel. Actually apart from it's own mass reduction you don't win enough to sustain buying a 2000 USD one and here is why: 

If you accelerate the car from 0 to 200 Km/h (full wot): the flywheel accelerates from 700 to 7000 rpm (in less than 2s) and then in each gear from about 5500 rpm to 7000 rpm. So it's rpm varies quite a lot and pretty fast. 

In the same time the driveshaft accelerates only from 0 to 1560 rpm in about 11s. 

Add to this that the driveshaft rotational mass center is quite close to it's center.


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## smack_ttrs (Mar 24, 2013)

cipsony said:


> What was the weight of the driveshaft of evo or subaru?
> Do you know what is the weight of the TT RS driveshaft?
> Do you know what is the equivalent diameter of a CF driveshaft vs the steel one that is supposed to replace?
> Do you know how much you can save with an aluminium driveshaft vs a steel one?
> ...


 1. 38.1 lbs for evo driveshaft 
2. no i haven't weighed the tt's 
3. didn't measure the cf subi driveshaft that was at the shop but it looked very similar in size to stock. not obviously way bigger or anything. 
4. you did read my post right?  38.1 stock and 26.1 aluminum. plus another 5 or so for the bracket/bearing that you lose going down to two piece. 

btw i never compared a light driveshaft to a flywheel but there are still acceleration gains to be had. more similar to a lighter wheel in theory. i do agree that since the weight is so much closer to the center of rotation it has less of an affect. my only reference is a friend that went to cf on his subi and felt it made much more of a difference than he thought it would. he may have been trying to justify the $ spent though  

again like i said in the previous post, the farther you take things the more money it cost and the less weight you find to take off. where each person's spending threshold is, is up to them.


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## cipsony (Mar 26, 2013)

smack_ttrs said:


> 1. 38.1 lbs for evo driveshaft
> 2. no i haven't weighed the tt's
> 3. didn't measure the cf subi driveshaft that was at the shop but it looked very similar in size to stock. not obviously way bigger or anything.
> 4. you did read my post right?  38.1 stock and 26.1 aluminum. plus another 5 or so for the bracket/bearing that you lose going down to two piece.
> ...


 Problem is that the TT RS driveshaft is around 26 lbs + it's long + it's made from 2 pieces already --> in this case the aluminium driveshaft would not save much as aluminium is not as strong as steel so you would need to add some material (maybe you could save 2~3Kg but I have my doubts) 

A CF driveshaft would probably save about ~6 Kg (compared to about 12Kg in the case of an evo) --> Btw, what is the weight of the evo CF driveshaft ? 

An example of weight saving that is cost effective: 
The IC Forge race weights with about 7Kg more than the Wagner evo 2 and it stays in the worst possible place (at the front of the car) + it has a smaller area in contact with air --> some solutions for weight removal are not just viable but a "must" while others are not applicable for the TT RS. 

I studied the possibility of making a CF drive-shaft: 
- I removed mine from the car and did all the measurements 
- I sent the details to a company that is manufacturing drive-shafts 
- I read a lot about CF drive-shafts and weight reduction impact (some websites figures are just myths) 
- The TT RS can't be made out of one piece only as it is too long so the diameter will have to be a lot bigger than the steel one. 
- Finally I decided to let it go and work on something else that is more cost effective  

Look at the video below and see the difference in diameter of the 2 drive-shafts + it reduces the weight because it doesn't have the center connection. 
http://www.youtube.com/watch?v=zC13EiuWSsg 

Now look at the picture of the TT RS driveshaft and you will understand what I mean: 
http://i1244.photobucket.com/albums/gg580/Ciprian_Chete/2011-10-27151835_zps4a6609b5.jpg


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## smack_ttrs (Mar 24, 2013)

cipsony said:


> Problem is that the TT RS driveshaft is around 26 lbs + it's long + it's made from 2 pieces already --> in this case the aluminium driveshaft would not save much as aluminium is not as strong as steel so you would need to add some material (maybe you could save 2~3Kg but I have my doubts)
> 
> A CF driveshaft would probably save about ~6 Kg (compared to about 12Kg in the case of an evo) --> Btw, what is the weight of the evo CF driveshaft ?
> 
> ...


 not sure how this turned into a driveshaft thread  

if the rs only weighs 26lbs that's great. the stock 3 piece evo is 38.1. i haven't looked around the evo forums in a while but it looks like they are making a 1 piece(didn't think that was possible) that is 15lbs. i agree it's a silly place to look for weight lose compared to the $ spent. 

on the i/c i like the wagner and of course it's lighter since it's tube and fin but bar and plate is normally more efficient. if the wagner can shed enough to cover the heat the current setup produces then it's the best choice. my only concern would be that it ends up heatsoaking on track. only way to really know is to log. if you're looking at lap times then there is a tipping point were the power loss over the whole lap is greater than the loss of corner speed due to the extra nose weight. again all questions only data aq can accurately answer.


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## JohnLZ7W (Nov 23, 2003)

Where Audi saved weight with the Ultra concept


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## Williamttrs (Mar 29, 2013)

JohnLZ7W said:


> Where Audi saved weight with the Ultra concept


Very cool. Thanks!


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## Williamttrs (Mar 29, 2013)

What about the fuel tank? Is it aluminum or steel. If steel, changing to aluminum could reduce the weight by about half.


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## smack_ttrs (Mar 24, 2013)

Williamttrs said:


> What about the fuel tank? Is it aluminum or steel. If steel, changing to aluminum could reduce the weight by about half.


most likely it's plastic. 
haven't looked under many vw/audi products in a while but even when i was working for a vw dealer back in the mid 80's they were using plastic tanks.

also since the tank is low and between the wheels this is probably the last place to bother looking for weight. start with weight high and at the nose if possible.


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## R5T (Apr 7, 2010)

The TT RS engine weigh 185 KG.
Dutch sportcar builder "Donkervoort" have develop there new GTO car in close cooperation with Audi's "quattro GmbH" and managed to reduce the engine weight to 160 Kg.
It's only 15 Kg they found but never the less it a reducing of 15 Kg.
Wonder what the next generation 2.5 TFSI engine will weight.


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## cipsony (Mar 26, 2013)

15 Kg from the front would be great.


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## R5T (Apr 7, 2010)

JohnLZ7W said:


> Where Audi saved weight with the Ultra concept


Nice concept, wrong engine.


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## Williamttrs (Mar 29, 2013)

R5T said:


> The TT RS engine weigh 185 KG.
> Dutch sportcar builder "Donkervoort" have develop there new GTO car in close cooperation with Audi's "quattro GmbH" and managed to reduce the engine weight to 160 Kg.
> It's only 15 Kg they found but never the less it a reducing of 15 Kg.
> Wonder what the next generation 2.5 TFSI engine will weight.


What did they do to save the weight? It does not sound like a change to aluminum as this would most likely save a lot more weight. 

On that same note, I really don't understand why Audi did not use an aluminum block. Aluminum blocks have been used in many high performance applications for quite a while. It just seems obvious to me that using aluminum would shave off a drastic amount of weight right where it is needed. I understand that the block would have to be a bit larger for strength, but I cannot imagine that this would be a major issue.


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## hightechrdn (Dec 9, 2011)

Williamttrs said:


> What did they do to save the weight? It does not sound like a change to aluminum as this would most likely save a lot more weight.
> 
> On that same note, I really don't understand why Audi did not use an aluminum block. Aluminum blocks have been used in many high performance applications for quite a while. It just seems obvious to me that using aluminum would shave off a drastic amount of weight right where it is needed. I understand that the block would have to be a bit larger for strength, but I cannot imagine that this would be a major issue.


Audi reused the basic VW 2.5L 5-cylinder design for the 2.5L TFSI engine... If you read the design overview PDF which is floating around, it has a lot of technical information on the TT-RS, including engine details. For example, the block of the 2.5L TFSI engine is made from a higher strength material/alloy than the regular cast iron VW 2.5. 

Remember that cost is a major driver of design for low volume cars like the TT-RS. Engineering and testing an aluminum, sleeved block would have driven up the R&D costs. Though aluminum would have saved weight, I am glad that the current high strength block will more than likely stand up to a tremendous amount of abuse.


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## R5T (Apr 7, 2010)

Williamttrs said:


> What did they do to save the weight? It does not sound like a change to aluminum as this would most likely save a lot more weight.
> 
> On that same note, I really don't understand why Audi did not use an aluminum block. Aluminum blocks have been used in many high performance applications for quite a while. It just seems obvious to me that using aluminum would shave off a drastic amount of weight right where it is needed. I understand that the block would have to be a bit larger for strength, but I cannot imagine that this would be a major issue.


The Donkervoort does not have the Airco pump anymore, to start with.
Further a new intake manifold, and some other custom parts.


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