# V8 Quattro performance mods



## sifu_dinan (Sep 8, 2003)

I'm currently in search of a decent V8 Q to buy, and I've found a couple good prospects in my price range. I've decided to set myself a limit of $10k on this entire endeavor, and since the cars I've found are around the 6-8 range I figured I have a bit of headroom to work with on the modding side of things. 
The thing is, while an eight cylinder engine in a car like this certainly makes sense, it's a bit underpowered for my tastes. My rule of thumb is to always have 100hp and 100ft lbs of torque for every 1000lbs the vehicle weighs. Few cars come like that from the factory, but most are certainly capable of it in the hands of the right tuner. 
The V8 Q is a bit too far under that line for me. I'd like to get this car somewhere close to the 400hp range. Now, in all the vehicles I've worked on, I've never come across a V8 engine that couldn't produce that much power. My only concern is figuring out a way to do this without forced induction. I'm certainly planning on researching a turbo or blower in the future if I end up enjoying this car and if my budget allows, but I'd really like to find a way to hit my mark or come fairly close to it on the motor alone. 
My question to y'all (yes, I know...I'm from the south







) is what should I start with? What are the typical things done to these engines to squeeze some performance out of them? Also, what's available to me in major mods that would allow me to get even more power out of the engine? I'm certainly interested in upgrading the brakes (though one of the cars I'm looking at has already done the conversion to Porsche 968 discs) as well as beefing up the suspension for some road racing, but my main concern now is getting enough power to move a two ton car at a decent rate.
I don't want a quarter mile screamer or a stripped down race car, I just want to have enough oomph under the hood to excite me. Being that the last performance car I had was a 2001 Z28, it's gonna take a bit more than the V8 Q has to do that.
So, any comments, suggestions, recommendations, questions, concerns, and especially LINKS that y'all could offer me on this would be greatly appreciated.










_Modified by sifu_dinan at 2:36 AM 1-11-2004_


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## Haiku Master (May 29, 2003)

*Re: V8 Quattro performance mods (sifu_dinan)*

Well... lets examine the options.
First: are you trying to find a 5-speed car or automatic. The reason I ask is that the 5-speed was only imported in 1991 and came with the 3.6L v8 at 240hp...meaning you've got a LONG way to go before you hit 400hp.
The 92-94 V8Qs are 280 hp and 295 ft-lbs from a 4.2L 32v...right there you get 40hp but you sacrifice the option of the 5-speed transmission...unless you start swapping trannies and such.
Naturally aspirated, it is POSSIBLE to hit your HP goal, but not your torque goal. The Audi V8 DTM race cars are the best tuned NA motors I've seen. 3.6L, 420hp @ 8200rpm, 285 ft-lbs @6000 rpm for the 1990 Season. 
By the 1992 Season, hp had increased to 470 hp (still 3.6L) and occured at 9500 rpm. The torque remained unchanged but moved up the powerband to 7000 rpm. 
Remember the following equation: hp = torque * rpm/5252 
In order to increase hp, increase torque, OR raise the rpm torque occurs at. I order to increase torque, you need more air in the cylinders at a given rpm, OR to burn the air/fuel mix more efficiently (advanced timing or higher compression). The highest I would go on pump gas is 11.0:1 compression. You are already at 10.6:1. Milling the head can easily raise this ratio but above this, knocking/detonation becomes an issue on pump gas. Intended Acceleration makes a chip claiming a 10% increase in hp/torque.
Increasing air in the chamber is tough to do without forced induction. CatCams makes a few aggressive grinds but they are over $2000 for the set. MTM makes a camset as well...but its over $4k!! The stock headers flow well and are pulse-tuned. 
The intake manifold can be upgraded by converting to the later A8-style variable geometry intake, which has bigger runners and a better throttle body. The V8 air filter is part of the upper engine cover. A cone filter would be difficult to accomplish, and the MAF is integrated into the intake manifold (yes, its THAT messed up).
The point I'm getting at is that this motor is tough to make big power on without FI. Another option you might want to consider - swapping in an S8 motor. The most modern S8 is a 4.2L 40v with variable intake manifold and variable cam timing as well. 360 hp and 310 ft-lbs of torque. To accomplish this, the S8 motors get revised cams, valves, valvetrain, pistons, exhaust, injectors, and naturally improved ECU programming. In this case, it seems easier to use the most modern variant of the motor with modern engine management and a factory hot-rod package. I am certain you will spend more than the cost of the motor trying to achieve similar results on the original V8Q motor.
Other modern motors worth considering: A6 4.2L is 340hp, as is the new S4 40v. The European models got all sorts of variations between 300 and 360hp but the cost of importing one might be prohibitive. The 97-99 A8 had 300 hp (40v) and the newer 40vs have 310hp.
You might find the V8 to be particularly lacking in torque. I watched a friend dyno an 01 TransAm - and I've never seen such a flat torque curve! The lower-displacement DOHC V8s will make power in a very different matter.
There are several options for upgraded brakes and suspension, which really really really waken up the car. It is MUCH too heavy for the small discs and G60 calipers and the suspension is tuned for luxury. 
What a novel. Guess I don't have better things to do on a Saturday night


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## sifu_dinan (Sep 8, 2003)

Wow, thanks for all the info. Much appreciated. 
I'm hoping to find a five speed, in fact I found one in the Seattle area that I may go take a look at. It's a bit on the high side in terms of both money and miles, but according to the seller the engine only has 40k on it. If so, wouldn't it have to be a newer one in the first place or does Audi still feed the aftermarket with it's older engines?
Is there any particular reason why these engines have a hard time making a decent amount of torque or is it just the limitation of the design? 
I'm guessing I should just look right into the turbo or s/c for this engine from the start. I would like to know, however, what are the typical things that I should do first? Like on my Z28, all good LS1 owners know that after doing the "free mods" (MAF screen, air silencer, EGR tube, t/b bypass, etc) you throw on a nice air lid, 3 inch catback, bigger throttle body, eventually toss on the LS6 intake and some long tube headers.......er, sorry. Kinda got off on a rant there. Is my mullet showing?








Anyways, I don't suppose you could point me to any sites that I should pay close attention to when looking for upgrades on this car? 
Thanks again for the advice.


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## Haiku Master (May 29, 2003)

*Re: (sifu_dinan)*

I have seen the car you refer to in Seattle. Black, 17" BBS wheels, big brakes. Guy wants too much for it. It's been for sale since June. When I talked to him he couldn't even tell me about the brakes (something I am always very interested in). But it WAS very well done and very well maintained. We got to share space in the "winner's circle"







at the NW Audi Club Pizza Feed in June.
Audi still supplies motors when need be, but they are quite expensive. The aluminum V8s cannot be rebuilt without going to a cast iron sleeve and custom pistons. The internal pieces are not available anywhere, as far as I know. 
Why no torque? Just the limitation of the design and low displacement. If you watch the power/torque out puts of the 4.2L you'll see what I mean. At the inception of the 4.2L, it made 295 ft-lbs. The flagship 4.2L 10 years later makes 310 ft-lbs with as much technology as Audi could throw at it (5v heads, variable intake/valve timing) however you will see that as time goes by, the torque curve gets flatter and flatter. 
There aren't any dead-giveaway easy mods to do on these motors. The LS6 intake swap on your LS1 is the same idea as the A8 intake on the early V8 motors. Much improved design, but still only good for a few hp. The factory did a decent job making power with it, but a lot of energy was spent ensuring it was lightweight and durable, as opposed to making a ton of power. Historically, Audi has always been being on specific output compared to say... BMW. Not sure why!
For exhaust: a single 3" would be weird, but a dual 2.25" or 2.5" would be great. Best of both worlds would be 60mm but thats hard to find parts for. There are no bolt-ons to speak for this motor. You will need to get real creative. 
According to Audi, the 3.6L has aluminum pistons AND RODS. I've never heard of or seen an aluminum rods and I know the later v8 motors have forged steek rods but I've never been inside the 3.6L. So keep in mind it might not like boost very much. I know the 3.6L has been twin turbo'd several times before with results well into the 400s.
I can't think of any sitesoff hand, because NO ONE tunes these cars. Sorry to say it, but mods are quite uncommon. Yahoo it for Intended Acceleration for the chip. There are a few sites in German for people who have swapped the motor into smaller cars but the motor still usually stays stock. Even then they provide very little info. Hohenester might make a turbo kit for it, but last time I looked their turbo kit for Audi A8 was 35,000 Euros or something. You know, more than it could possibly EVER be worth EVER EVER EVER. Yes I've had a bit to














tonight


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## sifu_dinan (Sep 8, 2003)

Yup, same car. And yeah, I believe he's asking quite a bit much for it. If it was to my liking I was planning on using the incredibly high mileage to drop the price. I don't suppose you have any pictures from said event I could see, just out of sheer curiority?
Seems this car isn't the best platform for mods. Unfortunatly I'm a very, very stubborn individual, especially when it comes to cars. Once I've decided I'll be driving a particular model car, nothing will stray me away from it.








There are two shops in Illinois recommended to me by a friend, though their names escape me at the moment. They've both done a lot of work on his S4 and he recommends I check them out, though as expected I didn't see too much on the website for V8Qs. 
I'd certainly prefer to use forged internals on any engine where I'd be boosting, so right now your idea of an engine swap might be the best solution. I guess I'll have to wait until after the purchase to see how much money I've got left over for mods. 
Thanks for all the tips.


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## Haiku Master (May 29, 2003)

*Re: (sifu_dinan)*

This is the best picture I have, unfortunately. Taken 06-19-03 by my roommate. I honestly didn't have any time to check out cars at the show. I spent the entire time taking to everyone about my 100LS. Funny - I was the second youngest owner in attendance with the oldest car. Whats up with that?
















This picture doesn't do the car justice. It looks a bit...blah in this shot, but it is stunning in person. For the rest of the pics from the show, check out this thread http://forums.vwvortex.com/zerothread?id=909691 
As for modding V8s....it is good to be stubborn! The suspension, while luxury tuned, has great geometry and drives great up to eight-tenths. I've only driven stock examples and compared to stock Coupe Quattro (equipped with Audi's "sport" suspension) it was surprisingly grippy and natural to drive. I dislike the electronic speed-sensitive steering assist "servotronic". It makes the steering too light and also non-linear. If your car has it, I'd suggest removing the servotronic relay just to see how you like it. No damage done and you can just put the relay back if you prefer.
At the very least, consider the later V8 4.2 for a swap. The extra 40 hp and 50 ft-lbs DOES wake up the car a lot. Also, there are occasional V8 motors on ebay. Last week I saw an A8 motor (300 hp, 300 ft lbs) which was buy-it-now for $2000. It had 97k miles and the seller said it was due for a timing belt (which is about a $1000 job) but it was in good shape save a dent in the timing belt cover (no damage behind it). A deal like that was pretty hard to refuse, but I already have a motor (no I'm still not telling anyone what it is) for my Coupe. 
One last note: if you plan on touching the bottom end of ANY of the Audi V8s you have to have to have to sleeve the cylinders. The manufacturing process for the V8 is "one-time use". If you want a rundown of that process I can take it from the factory service training for you. http://****************.com/smile/emthup.gif 
Good luck and let me know if you have any more questions or need any parts (wholesale) http://****************.com/smile/emthup.gif


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## sifu_dinan (Sep 8, 2003)

I'm actually going to check out a 1990 today that's just a few miles from where I live. Personally, there's no point in doing anything to the car if I have to drive an automatic. Might as well just let it be a luxury cruiser with only two pedals. 
Given that, would you happen to know what a transmission swap might run for one of these cars? I found the names of those two tuner shops in Illinois that I could take the car to, and if I can get this car cheap enough an engine and tranny swap might be well within budget.


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## audinut!$ (Nov 18, 2002)

*Re: (Haiku Master)*


_Quote, originally posted by *Haiku Master* »_
. Last week I saw an A8 motor (300 hp, 300 ft lbs) which was buy-it-now for $2000. It had 97k miles and the seller said it was due for a timing belt (which is about a $1000 job) but it was in good shape save a dent in the timing belt cover (no damage behind it). A deal like that was pretty hard to refuse, but I already have a motor (no I'm still not telling anyone what it is) for my Coupe. 


Was this the one in New Hampshire? If it was I'm pretty sure it was up on Ebay a month ago as well. The timing cover gives it away.

_Quote, originally posted by *Haiku Master* »_One last note: if you plan on touching the bottom end of ANY of the Audi V8s you have to have to have to sleeve the cylinders. The manufacturing process for the V8 is "one-time use". If you want a rundown of that process I can take it from the factory service training for you. http://****************.com/smile/emthup.gif 


I have been wondering about this so I may as well pose the question. These blocks are alusil (or coated with) correct? I just wondered if it might be possible to have them coated ( Swain Tech. comes to mind) and be able to get away without sleeving them? I imagine it's not or someone would be doing it already but I figure it might be worth a shot. It would make life very nice if it's possible.


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## Haiku Master (May 29, 2003)

*Re: (audinut!$)*


_Quote, originally posted by *Audi Factory Service Training Manual, published 1989* »_
The cylinder block is cast in hypereutectic alloy
of aluminum with a 17% silicon content and
weighs only 62 lbs. (28.1 kg).
Cylinder areas are specially treated to etch away
the aluminum and expose the hard silicon
crystals as a bearing surface for the pistons and
piston rings. This means that conventional
cylinder sleeves are not needed.
A fully balanced heat treated steel crankshaft is
used in the Audi V8 Quattro.
It is forged in a single plane and twisted while it is
still hot so the rod journals are at 90° to each
other. This process ensures the optimum
formation of the crankshaft counterweights. The
counterweights continue the momentum of the
power strokes from cylinder to cylinder for
smooth engine operation.
The crankshaft bearing caps are cast in nodular
iron for strength and reduce the expansion of the
main bearings in the aluminum cylinder block
when the engine is hot.
The lightweight connecting rods are also forged
from aluminum alloy. They are 154 mm long,
20.5 mm wide and weigh 621 grams, including
the bearing.
The aluminum slipper-skirt pistons are
electroplated with iron, and then thinly coated
with tin. In this way, the pistons and cylinder
bores seat in together during the engine break-in
period to give low-wear moving surfaces.
Piston crowns are cooled on the underside by a
jet spray of engine oil.


Any questions?


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## SuperGroove (Aug 20, 2000)

*Re: (Haiku Master)*

Why not buy the V8Q, and then swap in an LT1
It's been done in a Typ44 chassis


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## sifu_dinan (Sep 8, 2003)

*Re: (SuperGroove)*

Well that sounds interesting. I never thought about putting an F-body engine into this car.... 
I know a few places I could get a rebuilt LS1 or LT1 for a decent price. Maybe even an LT5 to keep the DOHC setup. I assume the Type44 is the V8Q platform, correct? Would you happen to have any links to more information about this kind of swap?
The only problem I forsee is finding a shop willing to take on the task. I'd love to perform the swap myself but I don't have access to a garage or any of the equipment neccessary. I don't think my leasing office would appreciate me swapping an engine in the parking lot.








I don't suppose a Tremec T56 would fit into the car, would it?


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## sifu_dinan (Sep 8, 2003)

If anyone knows any good sources for the newer A8 engines that Haiku Master was referring to, I'd appreciate a link or two.


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## Haiku Master (May 29, 2003)

*Re: (sifu_dinan)*

There isn't a truely "good" source for these since the cars are relatively rare. I watch ebay a lot, also there are a few Audi-specialist recyclers but A8s are rare there as well. Shokan, Force 5 Automotive, and Audi Connection come to mind immediately. Also check Campbell-Nelson Recyclers they might have one but not likely.


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## audinut!$ (Nov 18, 2002)

*Re: (sifu_dinan)*


_Quote, originally posted by *sifu_dinan* »_
The only problem I forsee is finding a shop willing to take on the task. I don't suppose a Tremec T56 would fit into the car, would it?










I know a shop in Maine that would be willing to do it. The problem is it would take him years to get it back to you. I think that the car would be better in the end if you kept quattro.


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