# How much horsepower a 1.8t can take. (a semi intelligent approach)



## 20aeman (Jun 8, 2006)

Horsepower=
Torque x Rev/
5250
We know that 99 percent of bolt on ko3 cars don't throw rods. Your average Ko3 with full bolt-ons makes roughly 230-240ftlbs to the wheels.
So lets move that torque all the way to the right side of the powerband. Instead of spiking at 3k,and getting max torque at 3.5k rpm...let's assume you'd hit maximum torque at 6.5k...or "redline" as we call it.
240x6500/5250=297.142857 WHP because we used WTQ in the formula. 
So you can have 297whp with a 99 percent assurance that you won't throw a rod (so long as peak torque is [email protected])









Now let's try and duplicate the stresses that some people put on their motors. I'm going to pick on swoleguy...mainly because he is such an extreme example:
We know that he made 329.3 wtq on a ko3/e85 combo...so let's move it up to 8k rpm (he has admitted to revving the motor up that high on his 50 trim)
329.3x8000/5250=501.790476
He could theoretically make 500+whp before he threw a rod...so long as peak torque (329wtq) hit at 8k rpm. 
So what the hell does this all mean? 
It means that if you want to make power on a stock block....better stow away the 28r/rs and find yourself a 35R.








Volumetric efficiency+ low boost+big turbo+good gas+revs= lots of safe horsepower.
Unsafe horsepower aka what everyone does in this forum:
volumetric inefficiency+small turbo+lots of boost+ piss gas + early torque onset.



_Modified by 20aeman at 5:49 AM 11-9-2008_


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## Teknojnky (Jun 1, 2002)

*Re: How much horsepower a 1.8t can take. (20aeman)*

so if I get this right: move the powerband in the higher revs and the engine can take roughly 500whp?


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## ForVWLife (Nov 12, 2004)

*Re: How much horsepower a 1.8t can take. (20aeman)*

to bad stock rods cant handle that much no matter what your math tells you
the hole in your block kills the equation everytime


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## FrankiEBoneZ (Jun 4, 2002)

*FV-QR*

350whp max for a very high level of safety on stock rods... if you do rods, 5-600 is fine.
/thread


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## brookrock (Sep 17, 2004)

*Re: FV-QR (FrankiEBoneZ)*

I love equations as much as the next guy, but that is a big no-no. I get what you are saying, but that doesn't mean it's safe.

Morgan


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## IzVW (Jul 24, 2003)

*FV-QR*

I like the work you did so I don't mean this as an insult... But most people are better off getting rods and a usable turbo rather than trying to find a place on local roads to spool a 35r!


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## mescaline (Jul 15, 2005)

Why is it better for torque to come on later than sooner? Engine wise, i would think that full torque kick at 6000rpm would be a lot more harsh than when engine is spinning slower.


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## not SoQuick (Jan 8, 2004)

*Re: FV-QR (IzVW)*

I just dont get how with rods costing 350-400$ why people chance it








imo if going BT its best to do clutch,rods and mounts before you even think of what turbo to put on there


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## 20aeman (Jun 8, 2006)

*Re: FV-QR (not SoQuick)*

I was being facetious with the original post. I obviously don't expect people to go slap on 35Rs on a stock block...but I do want them to understand the relationship between horsepower and torque. 
People who have huge torque curves are putting as much strain on the motor as the guy making 100 more hp than them.
I also wanted to show why Hondas, even though they have far more fragile motors, run more horsepower than we do on a stock block. 
If anything, this will be useful to the guy aiming for 300whp, where you are at the cusp of buying rods. For that extra safety buffer, it pays off to push the torque curve as far to the right as possible. You'll need less of it, to make more power.


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## NOLA_VDubber (May 24, 2007)

*Re: FV-QR (20aeman)*

http://****************.com/smile/emthup.gif Good post, indeed. It's amazing how many people cant grasp the concept of torque and power.


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## boosted b5 (Nov 1, 2004)

*Re: FV-QR (NOLA_VDubber)*

O2VW1.8T used a 35R on a stock block.. for a little while. it didnt explode.
my buddy made 496Whp on a stock integra GS-R block with 150k on it. on a 3076R at 21psi, stock never touched engine. stock head, intake, head bolts, rod bolts, rods, pistons, rings. engine was a junk yard motor. http://****************.com/smile/emthup.gif 
went 11.01 @ 128 at 18psi, on 24.50x8.5 slicks, on stock axles, b16 tranny, and springs and shocks, no traction bars, no lsd, with a clutch master stage 5 4 puck clutch.


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## theswoleguy (Jan 25, 2006)

*FV-QR*

It makes plenty of sense, more torque down low on a slower spinning motor, the motor has to absorb more stress vs spinning faster, less load up on stress. Large torque spikes are killer, but in the same sense, jumping 2-300wtq in 500 rpms can be just as detrimental to the block. Plenty of guys have done it but its based off a good tune as well, Pete (O2Vw1.8t) and Dan (GT-ER) did it for a while. It is also based off how good the tune is, not saying a tune prevents a block from inventing knew ways to vent crankcase gases, but a better tune helps prevent knock or det which on stock bottom end will be the end on stock rods. 
It is also how well you treat your car, i ran 30# spikes and retarded power on a ko3, daily, 83k miles i replaced my first stock turbo (exhaust side oil seal went), i also dont drive with a style of "foot up/Foot down" with my right foot at 93k i went big turbo, the stock ko3 i got for 100 and it bought me time to finish my parts other then smoke screening around town. Another reason i went 50trim .63 slower spooling
AND yes 8k stock block, 50trim .63, 23#s, 96k miles today




_Modified by theswoleguy at 10:01 PM 11-9-2008_


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## EpicWin (Nov 6, 2008)

*Re: How much horsepower a 1.8t can take. (20aeman)*

Deleted post so semi-intelligent conversation may continue... sometimes sarcasm is personally internalized on the interwebs


_Modified by EpicWin at 12:12 PM 11-10-2008_


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## theswoleguy (Jan 25, 2006)

*FV-QR*

wtf







level of boost has nothing to do with our motors, x boost on ko3 is not the same as x boost on a 35r, 
You = Epic FAIL
You ≠ Epic Win


_Modified by theswoleguy at 11:14 PM 11-9-2008_


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## GLI_jetta (Jan 3, 2006)

*Re: How much horsepower a 1.8t can take. (ForVWLife)*


_Quote, originally posted by *ForVWLife* »_to bad stock rods cant handle that much no matter what your math tells you
the hole in your block kills the equation everytime









its just funny the way you wrote that lol...


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## EpicWin (Nov 6, 2008)

*Re: FV-QR (theswoleguy)*


_Quote, originally posted by *theswoleguy* »_wtf







level of boost has nothing to do with our motors, x boost on ko3 is not the same as x boost on a 35r, 
You = Epic FAIL
You ≠ Epic Win

_Modified by theswoleguy at 11:14 PM 11-9-2008_

Aren't you the guy quoted by OP as being the extreme fail?


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## speeding-g60 (Aug 1, 2004)

*Re: How much horsepower a 1.8t can take. (EpicWin)*


_Quote, originally posted by *EpicWin* »_Blows my mind the levels of boost people are running in this forum. Now this is the internet, so you also can use this formula:
Claimed lbs of boost past 15, assume x - 1.47= actual level of MAP
If you like to measure the German way (why otherwise?):
Ffor every tenth over 1 bar, I assume 1 hot rod sticker on 1/4 panel window. Makes a good scale for boy-racer insanity. 

so, Seth, did you go to Pacific Waterlands? cuz if you did, you would have seen a real world example of >550 WHP with greater than 36 psi on a 4cyl 1.8T with GT35R in a rabbit. that car does half-track burnouts..... and still blows off the tires on top of 3rd and 4th, yet still manages low 11's @ 130.
it has some stickers on it. and its a real car. not some imaginary interwebz wish-creation. how do i know? cuz its mine. and anytime you go down to woodburn and see it, you'll know it. lemme know if you want to see video of it.....


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## 20aeman (Jun 8, 2006)

*Re: FV-QR (EpicWin)*


_Quote, originally posted by *EpicWin* »_
Aren't you the guy quoted by OP as being the extreme fail?

lolz. When did I say "epic failz" FWIW, Josh and I have basically done the same stuff...so I would be insulting myself.


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## 20aeman (Jun 8, 2006)

I'm also going to practice what I preach. 
E85, 50 trim, 1.1 bar, <250wtq, >300whp. 
I'm gonna play with a cam gear...retard cam timing by 4-5 degrees to push the powerband 500rpm to the right...then rev it to the 7k limiter.
If I'm short of my goal, I'll throw on an intake manifold or something


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## theswoleguy (Jan 25, 2006)

*Re: FV-QR (EpicWin)*


_Quote, originally posted by *EpicWin* »_
Aren't you the guy quoted by OP as being the extreme fail?

yes to being quoted but in no instance a fail at all bc even after all that my block is still intact and was using it to base of his equation and that 330 is about the limit of stock rods
reading > You
btw at 14 post count go make a thread about a BOV or which dp is best


_Modified by theswoleguy at 1:58 AM 11-10-2008_


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## 20aeman (Jun 8, 2006)

*Re: (mescaline)*


_Quote, originally posted by *mescaline* »_Why is it better for torque to come on later than sooner? Engine wise, i would think that full torque kick at 6000rpm would be a lot more harsh than when engine is spinning slower.


The main issue is ignition timing. You have to understand that the fuel is ignited BTDC, not ATDC. This means that while the piston is traveling up, the fuel is ignited and expanding. Since the piston is moving at a slower rate of speed and has a higher dwell time...there is a larger window of opportunity for detonation to break stuff. 



_Modified by 20aeman at 4:57 AM 11-10-2008_


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## engineerd18t (Dec 12, 2007)

*Re: (20aeman)*

What are our engine good for rpm-wise? I've got the k03 now so I dont like to go above 6k but I can see these engines getting well above 7k. I agree with moving the torque curve to the right...


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## 20aeman (Jun 8, 2006)

*Re: (bbeach)*


_Quote, originally posted by *bbeach* »_What are our engine good for rpm-wise? I've got the k03 now so I dont like to go above 6k but I can see these engines getting well above 7k. I agree with moving the torque curve to the right...

No one really knows and as such, it becomes a matter of preference. I would personally feel comfortable going up to 7k on a stock head. I'm a very careful person though.


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## NOLA_VDubber (May 24, 2007)

*Re: (20aeman)*

I rev to 7.5K all day long on stock head


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## lugnuts (Jul 26, 2001)

we made a 552 whp and about 410 wtq on a stock AEB motor, valve cover to oil pan. Peak tq was 6500-7000 rpm and peak hp was 7800, still climbing but we decided it might be a good idea to stop there








Dont try this at home.


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## DK_GTI_racer (Oct 4, 2007)

*Re:*

Makes all the sence in the world, a danish tuner i know for every builds he makes on stock rods always uses GT30 or GT35 and those cars run easy on stock rods and everything around 380whp etc. even with w/m injections etc. - but the high and fast torgue on k04, GT25, GT28rs is the snapper - thats why i upgraded - too scared and besides i have plenty mods planned


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## IzVW (Jul 24, 2003)

*Re: How much horsepower a 1.8t can take. (EpicWin)*


_Quote, originally posted by *EpicWin* »_
Ffor every tenth over 1 bar, I assume 1 hot rod sticker on 1/4 panel window. Makes a good scale for boy-racer insanity.


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## gticrazy1.8t (Apr 17, 2008)

*Re: How much horsepower a 1.8t can take. (IzVW)*

bigger turbo= better rods theres no equation to tell us that its safe to say if you want fast dont be dumb upgrade the right stuff: rods, injectors, pistons, rings, head gasket all that stuff should be at least looked at if you want it to be a reliable build if you goin for honda power then just pump up the boost on a huge turbo with stock internals and watch the smoke fly the first time i made 312 hp on 19 lbs w/ a k04 after i changed the rods, pitons, rings, injectors, head and head gasket with a 28rs with revo big turbo software 468 hp with 530 ft/lbs tourqe on 15lbs on 93 pump gas and it my daily driver it pays right to do it right


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## veedubwolfsburg (Jun 4, 2007)

*Re: How much horsepower a 1.8t can take. (gticrazy1.8t)*

You're saying you made 468hp with a GT28rs on 15psi with REVO?


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## speeding-g60 (Aug 1, 2004)

*Re: How much horsepower a 1.8t can take. (veedubwolfsburg)*


_Quote, originally posted by *veedubwolfsburg* »_You're saying you made 468hp with a GT28rs on 15psi with REVO?

dont forget the 530 WTQ and pump gas.....


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## -Khaos- (Dec 22, 2003)

All this is true, it's kinda basic really...
But remember our heads flow like crap, we we'll never make that "shoot for the moon" kind of power (where it keeps raising exponentially until rev limiter). It'll always look like a hump.
Now, do you want a nice broad hump, or a taller shorter hump later in the RPMs? Those are basically your choices on stock block/head. 


_Modified by -Khaos- at 8:28 PM 11-10-2008_


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## DonSupreme (Apr 11, 2006)

*Re: FV-QR (not SoQuick)*


_Quote, originally posted by *not SoQuick* »_I just dont get how with rods costing 350-400$ why people chance it








imo if going BT its best to do clutch,rods and mounts before you even think of what turbo to put on there









It always ends up being much more expensive than that..


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## theswoleguy (Jan 25, 2006)

*FV-QR*

rods will end up costing you about $750 not 350 lol. Theres rings, head gasket, VC gasket, bearings, bolts and a few other things in there


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## 20aeman (Jun 8, 2006)

*Re: (-Khaos-)*


_Quote, originally posted by *-Khaos-* »_All this is true, it's kinda basic really...
But remember our heads flow like crap, we we'll never make that "shoot for the moon" kind of power (where it keeps raising exponentially until rev limiter). It'll always look like a hump.
Now, do you want a nice broad hump, or a taller shorter hump later in the RPMs? Those are basically your choices on stock block/head. 

_Modified by -Khaos- at 8:28 PM 11-10-2008_

50 trim, 16 psi:


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## -Khaos- (Dec 22, 2003)

Yeah, but that's pretty low boost, probably not quite maxing out the head. Though the TQ still drops off towards the end.
By "reaching for the sky" I meant something like this.


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## cincyTT (May 11, 2006)

LOL, always with the best graphs!!!


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## skywalkersgti (Mar 27, 2007)

*Re: How much horsepower a 1.8t can take. (ForVWLife)*

seen 35r stock motor.26psi on revo 440 software.
also my own car. 25psi on3076/ 440cc file stock motor 440inj. stock fuel pump too


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## velocity196 (Feb 19, 2006)

*Re: How much horsepower a 1.8t can take. (20aeman)*

id like to see you run a gt35r at 500whp on a stock bottom end http://****************.com/smile/emthup.gif


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## skywalkersgti (Mar 27, 2007)

*Re: How much horsepower a 1.8t can take. (velocity196)*


_Quote, originally posted by *velocity196* »_id like to see you run a gt35r at 500whp on a stock bottom end http://****************.com/smile/emthup.gif 

i did a 30r on 440's stock pump and a440file. 25psi. lol car went [email protected] lol


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## [email protected] (Apr 25, 2007)

*Re: (-Khaos-)*


_Quote, originally posted by *-Khaos-* »_All this is true, it's kinda basic really...
But remember our heads flow like crap, we we'll never make that "shoot for the moon" kind of power (where it keeps raising exponentially until rev limiter). It'll always look like a hump.


I don't know if I agree with that. This is a bone stock AEB head, just a good intake manifold. Adding cams would flatten out that torque curve and extend it towards redline, meaning HP would keep climbing.


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## IzVW (Jul 24, 2003)

*FV-QR*

LOL Club18t mspaint warz ftw.


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## dochalliday (Jun 17, 2008)

*Re: FV-QR (IzVW)*

This conversation is very interesting but there is two parts of the "equation" that you all are missing.
1) If you don't know how much hp/torque your car can take, use someone that does.
2) Can you as a driver handle that much power? Believe it or not most can not!


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## -Khaos- (Dec 22, 2003)

*Re: ([email protected])*


_Quote, originally posted by *[email protected]* »_
I don't know if I agree with that. This is a bone stock AEB head, just a good intake manifold. Adding cams would flatten out that torque curve and extend it towards redline, meaning HP would keep climbing. 


Well true, but I was thinking more along the lines of stock AWP, AWW, AWD engines.
Once you start going BIG turbo, swapping heads, cams and intake manifold... On a stock bottom end... You gotta wonder why they'd keep the stock rods. 
I guess i shouldn't of said "never" in my previous post.


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## luv2exl8t (Apr 11, 2008)

*Re: (-Khaos-)*

so let me get this straight i just picked up an awp engine it is goin in my mk3 but the motor i was planning on just doing seals rings and bearing and turning the crank just basicall freshening up the motor so to get the most hp out of my motor i should put a big turbo on and change the rods witch will allow me to rev the motor a little further? just put it in simple forum i understand the difference between hp and torque


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## gdoggmoney (Feb 21, 2004)

*Re: How much horsepower a 1.8t can take. (20aeman)*


_Quote, originally posted by *20aeman* »_Horsepower=
Torque x Rev/
5250
We know that 99 percent of bolt on ko3 cars don't throw rods. Your average Ko3 with full bolt-ons makes roughly 230-240ftlbs to the wheels.
So lets move that torque all the way to the right side of the powerband. Instead of spiking at 3k,and getting max torque at 3.5k rpm...let's assume you'd hit maximum torque at 6.5k...or "redline" as we call it.
240x6500/5250=297.142857 WHP because we used WTQ in the formula. 
So you can have 297whp with a 99 percent assurance that you won't throw a rod (so long as peak torque is [email protected])









Now let's try and duplicate the stresses that some people put on their motors. I'm going to pick on swoleguy...mainly because he is such an extreme example:
We know that he made 329.3 wtq on a ko3/e85 combo...so let's move it up to 8k rpm (he has admitted to revving the motor up that high on his 50 trim)
329.3x8000/5250=501.790476
He could theoretically make 500+whp before he threw a rod...so long as peak torque (329wtq) hit at 8k rpm. 
So what the hell does this all mean? 
It means that if you want to make power on a stock block....better stow away the 28r/rs and find yourself a 35R.








Volumetric efficiency+ low boost+big turbo+good gas+revs= lots of safe horsepower.
Unsafe horsepower aka what everyone does in this forum:
volumetric inefficiency+small turbo+lots of boost+ piss gas + early torque onset.

_Modified by 20aeman at 5:49 AM 11-9-2008_


I knew I liked you for a reason. You are smart. 
Don't forget the stock K03 exhaust manifold and ko3s which pretty much act as heat retaining devices.


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## 20aeman (Jun 8, 2006)

*Re: How much horsepower a 1.8t can take. (gdoggmoney)*


_Quote, originally posted by *gdoggmoney* »_

I knew I liked you for a reason. You are smart. 


It's simply a misunderstanding. I'm a moran.









_Quote, originally posted by *gdoggmoney* »_
Don't forget the stock K03 exhaust manifold and ko3s which pretty much act as heat retaining devices. 

Yep. Which is why everyone should upgrade to bigger turbos.


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## Spa_driver (Jul 31, 2005)

*Re: FV-QR (IzVW)*


_Quote, originally posted by *IzVW* »_LOL Club18t mspaint warz ftw.

Those were the days.....when we were young.








--Highspeeder


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## 20aeman (Jun 8, 2006)

*Re: FV-QR (Spa_driver)*

Just thought I'd bump this:
stock block ls/vtec (way more fragile motor than the 1.8t):








Why is it staying together? Look at the torque. 
I'll be doing something very similar to this very shortly.


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## 5P4RK4 (Jun 24, 2004)

FAKE

no real person can be named HILARIO COLON


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## 20aeman (Jun 8, 2006)

*Re: (5P4RK4)*


_Quote, originally posted by *5P4RK4* »_FAKE

no real person can be named HILARIO COLON

Lolz


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## HidRo (Sep 19, 2003)

*Re: (5P4RK4)*


_Quote, originally posted by *5P4RK4* »_FAKE

no real person can be named HILARIO COLON

AHahahaha
So, my car has this graph:








Stock internals and all (k04-023, etc).
I have about 340NM (I believe it's around 250ftlb).
I'm reaching the limit of 400NM (300ftlb) at the engine, not the wheels.
So, the limit is TQ or WTQ?
Thank you for your reply.










_Modified by HidRo at 11:42 AM 1-6-2009_


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## enginerd (Dec 15, 2001)

You guys are not pioneers on the big power stock bottom end concept - there were lots of engines blowing in 2002 - 2003 from 300 - 350 whp on stock rods. big/med/small turbos - you can try all you want all you will get is bent rods it just takes time or a little boost spike. 1 single boost spike on these larger turbos with adequate timing can bend a rod. sure run a big turbo at low boost, or high boost with low timing - it's pretty slow


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## 20aeman (Jun 8, 2006)

*Re: (enginerd)*


_Quote, originally posted by *enginerd* »_You guys are not pioneers on the big power stock bottom end concept - there were lots of engines blowing in 2002 - 2003 from 300 - 350 whp on stock rods. big/med/small turbos - you can try all you want all you will get is bent rods it just takes time or a little boost spike. 1 single boost spike on these larger turbos with adequate timing can bend a rod. sure run a big turbo at low boost, or high boost with low timing - it's pretty slow 

The goal isn't just horsepower. It's having a big disparity between horsepower and torque. 
and as far as it being slow....we aren't talking 28rs turbos or gasoline, so all that crap is out of the equation.


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## theswoleguy (Jan 25, 2006)

*FV-QR*

lol still going i love it


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## Zrod18T (Oct 6, 2008)

*Re: FV-QR (theswoleguy)*

There should be more posts like this


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## -Khaos- (Dec 22, 2003)

Serious question:
Do you guys know of any other car enthusiasts who buy big heavy cars with an engine that has a big broad usable powerband, then go out trying to make it into the opposite?
I just can't wrap my head around how much work some people are willing to do to turn their VW into a Honda. Because that's really what you're after: Lightweight, no TQ, high revs, high HP. All you have to do is go visit your neighborhood highschooler and offer to buy his car for pennies of what it would take you to modify a 1.8T to run like his Honda.


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## theswoleguy (Jan 25, 2006)

*FV-QR*

isnt that the truth. Think about all the money we have put into some of our cars, aside looks and everything else we love, like leather and heated seats. but 6k into a honda and the bitch flies lol


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## ncsumecheng (Nov 1, 2005)

*Re: FV-QR (theswoleguy)*

NO! 90% of this argument is WRONG!
Torque and horse power forces on a rod are actually not the dominant force. Inertial force from the RPM you are running is actually higher.
But, since a motor makes toque and has an inertial force on it to get the total you have to factor in both.
If you make the same wtq at a higher RPM on stock rods, it is more force on the rod than that wtq at a very low RPM.


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## TooLFan46n2 (Oct 18, 1999)

*Re: (HidRo)*


_Quote, originally posted by *HidRo* »_

So, my car has this graph:








Stock internals and all (k04-023, etc).



_Quote, originally posted by *-Khaos-* »_Serious question:
Do you guys know of any other car enthusiasts who buy big heavy cars with an engine that has a big broad usable powerband, then go out trying to make it into the opposite?
I just can't wrap my head around how much work some people are willing to do to turn their VW into a Honda. Because that's really what you're after: Lightweight, no TQ, high revs, high HP. All you have to do is go visit your neighborhood highschooler and offer to buy his car for pennies of what it would take you to modify a 1.8T to run like his Honda.


I agree, I understand boost is addicting but to me this is a power curve (granted another 50HP would be ideal). Nice early usable flat torque curve and the HP picks up and holds to redline. Thats why I choose the k04-20 (Okay the real reason is I'm poor) but the car is a fun to drive. It puts you in your seat in any gear at almost any RPM. To me the perfect match would be a DSM 16G turbo for a street car. Awesome compressor map (for street use) should yield a nice meaty powerband.

One thing I'd really like to know is everyone says our heads can't flow. I know it certainly outflows the old 1.8 16v heads but how does it compare to say our rival b16 or 1st gen dsm 2.0 heads. I always hear talk but have never seen a comparison.
EDIT: Okay I just noticed the graph is scaled differently on each side. Still not to bad, but not as impressive as I initially thought.










_Modified by TooLFan46n2 at 10:40 PM 1-6-2009_


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## 20aeman (Jun 8, 2006)

*Re: FV-QR (ncsumecheng)*


_Quote, originally posted by *ncsumecheng* »_NO! 90% of this argument is WRONG!
Torque and horse power forces on a rod are actually not the dominant force. Inertial force from the RPM you are running is actually higher.
But, since a motor makes toque and has an inertial force on it to get the total you have to factor in both.
If you make the same wtq at a higher RPM on stock rods, it is more force on the rod than that wtq at a very low RPM.


I find this extremely hard to believe.


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## 20aeman (Jun 8, 2006)

*Re: (-Khaos-)*


_Quote, originally posted by *-Khaos-* »_Serious question:
Do you guys know of any other car enthusiasts who buy big heavy cars with an engine that has a big broad usable powerband, then go out trying to make it into the opposite?


It's not the engine that gives you a big broad usable powerband, it's the turbo. Since turbo kits are often built around the needs of the user....I get to dictate powerband, not VW. If I shift at 7k rpm...I land north of 5k. As a result, I don't need anything below that.


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## -Khaos- (Dec 22, 2003)

*Re: (20aeman)*

*TooLFan46n2*: if you search hard enough (search was down for me) you'll find a graph of the head flow of a typical (non AEB) 1.8T head compared to commonly used Honda heads. It's pretty horrible. These heads were NOT made to flow very much, leading me to my next point:

_Quote, originally posted by *20aeman* »_
It's not the engine that gives you a big broad usable powerband, it's the turbo. 


I see what you're saying, but the turbo is only one part. I've been told that the reason engines like these make so much TQ is due to the head being restrictive, giving us more TQ (but less HP up top). I'm not sure I agree with that, but be that as it may, the engine is simply not made to rev high efficiently, and that has more to do with it than just the turbo itself, the head plays a large role.
Sure you can shift the powerband to the right like you were saying, but that's not using the engine in the way it was designed, so then you practically have to redesign it and start modifying it so it becomes more efficient.


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## NOLA_VDubber (May 24, 2007)

*Re: FV-QR (20aeman)*


_Quote, originally posted by *20aeman* »_
I find this extremely hard to believe. 

I'm not agreeing or disagreeing, as I haven't done the math or looked into the matter, but...
If you want to calculate inertial force on the rod due to moving the piston head up and down at some given rpm, it's not too difficult (after making certain assumptions to simplify the problem). Using newton's 2nd law, the rod must exert a force on the piston equal to it's mass (the piston's, that is) times the piston's acceleration at any point along it's path. You can model the rotating assembly as a crank-slider 4-bar mechanism and use some dynamics to solve for the acceleration of the piston as a function of rpm. From newton's third law, you can say that the force that the rod puts on the piston is equal and opposite the force the piston puts on the rod. There's still the matter of solving the inertial force from the rod's mass...but that might be a bit tricky due to it's rotation and planar motion.
If I have time later, I'll see if I can't put something together. Any ME students out there looking for some extra credit feel free to solve it and plot up the results http://****************.com/smile/emthup.gif


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## 1.BillyT (Aug 2, 2000)

*Re: FV-QR (NOLA_VDubber)*

490 on a stock AEB bottom end lasted about 20 dyno pulls and 5 1320 passes. Granted, that particular engine had lots of 430ish wheel miles on it, some road racing even.
But yeah, it was destined to fail.
I never had a motor fail with less than 400 wheel, though. But I never just left one alone long enough to give it the chance to fail with anything less.


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## 5inchMAF (Sep 12, 2007)

*Re: FV-QR (1.BillyT)*

the difference between 6000 rpm and 7000 rpm is only about 15%
but the stress on your reciprocating parts go up about 36% though
stress on your rods goes up exponentially with engine speed.
so 250tq puts ALOT more stress on your rods at 7000 rpm than it is at 3000 http://****************.com/smile/emthup.gif


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## 18Lturbo (Nov 28, 2005)

*Re: How much horsepower a 1.8t can take. (gticrazy1.8t)*

30r, stock head, stock rods, still reving to 7.5k all day long... 16psi

former rotomaster owner... 


_Modified by 18Lturbo at 3:17 AM 1-8-2009_


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## 20aeman (Jun 8, 2006)

*Re: FV-QR (BIGGEE TALLS)*


_Quote, originally posted by *BIGGEE TALLS* »_

so 250tq puts ALOT more stress on your rods at 7000 rpm than it is at 3000 http://****************.com/smile/emthup.gif

250ftlbs of torque is 250ftlbs of torque. Regardless of the rpms, it'll apply the same amount of force. Certainly, inertial forces will increase with RPMS...but those forces are the same at 7000rpm whether you have 100ftlbs of torque or 300ftlbs. 
These forces are seperate and are practically exclusive of each other.



_Modified by 20aeman at 1:53 AM 1-8-2009_


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## theswoleguy (Jan 25, 2006)

*FV-QR*

ya but torque at 7k is a increase it seems like 100+ hp jumps per 500 rpm, also just a theory i have, maybe someone can say otherwise. just speculating. wouldnt say especially on ko3 monsters, 330 wtq be more dangerous on rods at 3300 rpms vs 7k not that it flows up there lol, i mean in a special universe like where super man is from, i mean isnt there more load and pressure and build up time on a system spinning slower, then a system moving up n down faster, bc not only is one piston being pushed down from combustion but also pulled down bc other pistons are exerting rotational forces on the crank as well?


_Modified by theswoleguy at 8:19 AM 1-8-2009_


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## NOLA_VDubber (May 24, 2007)

*Re: FV-QR (20aeman)*


_Quote, originally posted by *20aeman* »_
250ftlbs of torque is 250ftlbs of torque. Regardless of the rpms, it'll apply the same amount of force. Certainly, inertial forces will increase with RPMS...but those forces are the same at 7000rpm whether you have 100ftlbs of torque or 300ftlbs. 
These forces are seperate and are practically exclusive of each other.
_Modified by 20aeman at 1:53 AM 1-8-2009_


Very ture


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## engineerd18t (Dec 12, 2007)

*Re: FV-QR (NOLA_VDubber)*

Bump for a good thread. I think with proper boost control and careful tuning you can better prevent torque spikes. At least with a k03 at 20psi I got 250wtq, with some lousier timing. I'd love to have the same tq at 7krpm. Has anyone done any kind of analysis on the forces at various rpms?


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## 20aeman (Jun 8, 2006)

this thread is hard to kill








fwiw, I sort of abandoned the idea...but the theory is still sound.
Just decided that I want to make craploads of power since I'm already spending the money.


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## ryans05gli (Feb 20, 2009)

*Re: FV-QR (20aeman)*


_Quote, originally posted by *20aeman* »_
250ftlbs of torque is 250ftlbs of torque. Regardless of the rpms, it'll apply the same amount of force. Certainly, inertial forces will increase with RPMS...but those forces are the same at 7000rpm whether you have 100ftlbs of torque or 300ftlbs. 
These forces are seperate and are practically exclusive of each other.
_Modified by 20aeman at 1:53 AM 1-8-2009_

actually since we are talking about the bottom end, these forces, while acting independently, are actually acting on the same parts. but when we are talking about parts failing its about the SUM of the forces acting on the parts that cause them to fail. at high rpms and high torque the internals are transferring massive amounts of energy (if thinking of it in the kinetic energy sense) when a part is forced to transfer more energy than it was originally designed to handle then that part has a chance of failing. not saying it will (look up fracture//failure mechanics) but the more you approach the threshold of the original design, the more likely it is to fail.


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## 2bar b3 passat (May 23, 2005)

*Re: FV-QR (ryans05gli)*

very good thread we need more like this


_Modified by 2bar b3 passat at 1:55 PM 2-25-2009_


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## hypothetical (Oct 20, 2006)

*Re: FV-QR (2bar b3 passat)*

The time it took for me to read these three pages. I could pull the motor apart and install a set of Scats or IEs and move on to the next technical issue. All the math in the world about HP/Torque means nothing if the math about the rod strength has already been determined (350Ftlbs+/-)
I say for anyone building a big horsepower 1.8t, don't "BT" until you upgrade connecting rods in the block. Then the sky's the limit... Unless you're Lugnuts then do what you'd like.
I did 408Whp for a year on an AEB and it never had an issue. Made 435Whp for a week and Kablamo. The edge in a fine one and not to be played with.


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## 20aeman (Jun 8, 2006)

*Re: FV-QR (hypothetical)*


_Quote, originally posted by *hypothetical* »_The time it took for me to read these three pages. I could pull the motor apart and install a set of Scats or IEs and move on to the next technical issue. All the math in the world about HP/Torque means nothing if the math about the rod strength has already been determined (350Ftlbs+/-)
I say for anyone building a big horsepower 1.8t, don't "BT" until you upgrade connecting rods in the block. Then the sky's the limit... Unless you're Lugnuts then do what you'd like.
I did 408Whp for a year on an AEB and it never had an issue. Made 435Whp for a week and Kablamo. The edge in a fine one and not to be played with.

Haha, it took you 10 hours to read this thread? But in all seriousness, I agree with you. Hence biting the bullet on the drop in rods.


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## hypothetical (Oct 20, 2006)

*Re: FV-QR (20aeman)*


_Quote, originally posted by *20aeman* »_
Haha, it took you 10 hours to read this thread? But in all seriousness, I agree with you. Hence biting the bullet on the drop in rods.

Took me an hour to read the thread... What's that tell you? LOL. I didn't say pull the motor from the car. Anyway. Good choice. You gonna like the outcome and the piece of mind.


_Modified by hypothetical at 1:43 PM 2/26/2009_


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## b5boost (May 31, 2007)

1.8T + Huge amounts of Boost = Kaboom... If you want a balls out safe HP car buy an RS4 or an RS6... R8 etc...


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## themachasy (Jan 28, 2006)

*Re: (b5boost)*


_Quote, originally posted by *b5boost* »_1.8T + Huge amounts of Boost = Kaboom... If you want a balls out safe HP car buy an RS4 or an RS6... R8 etc...

No? RS4s can't be upgraded easily nor can R8s. Put rods in your 1.8t and make power!


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