JonnyC's Audi S3 Project..

[DanGB]

do you think there will be much difference in low end power going from the stock (BWA) CR 10.5 to 9.5?

[jonnyc]

do you think there will be much difference in low end power going from the stock (BWA) CR 10.5 to 9.5?

A little, but for sure you will make more top end power.. It really depends what your after, if your sticking with the 28 then dont go any lower than 9.5:1.. JE now do 10.25:1 compression pistons for non tapered rods..

[Hurdy]

All very interesting.   

I've gone for the RSR VF piston and rod upgrade with the GT2871R you sold to me Jonny. They are 8.8:1 comp ratio and (so I'm told) should be better for me in conjunction with the DSG and a ECU/TCU upgrade to allow me to run upwards to 8krpm on the GIAC software. I've been told that boost will be around 200rpm later(ish) than with the higher comp  pistons, but will ultimately give me around 20-30 bhp at the top end through more flexibility with boost/timing whilst remaining very tractable at the lower rpms.

Does this sound about right?

[jonnyc]

All very interesting.   

I've gone for the RSR VF piston and rod upgrade with the GT2871R you sold to me Jonny. They are 8.8:1 comp ratio and (so I'm told) should be better for me in conjunction with the DSG and a ECU/TCU upgrade to allow me to run upwards to 8krpm on the GIAC software. I've been told that boost will be around 200rpm later(ish) than with the higher comp  pistons, but will ultimately give me around 20-30 bhp at the top end through more flexibility with boost/timing whilst remaining very tractable at the lower rpms.

Does this sound about right?

Sounds about right, just bare in mind revving to 8k on the standard valve train is really pushing it.. Are you having the head rebuilt?

Same deal as me too, your leaving yourself the option to go bigger in the future if you wish.. Really you only want to (in my case can afford to) build a forged engine once..

[Hurdy]

The valvetrain will stay the same. It looks like they will go as far as setting the ecu limit at 7,800rpm with the change up at 7,600, so not quite as high as I originally thought. I don't know if I'll eventually go bigger as the FWD will probably be at the limit with the GT2871

[jonnyc]

The valvetrain will stay the same. It looks like they will go as far as setting the ecu limit at 7,800rpm with the change up at 7,600, so not quite as high as I originally thought. I don't know if I'll eventually go bigger as the FWD will probably be at the limit with the GT2871

At 7600 you should be ok.. Yeah I agree, around 450hp with FWD is about the limit without going to extreme measures..

[Ryan_Evo]

Soon changed your mind about the gt35!  
gt3582 spools 500rpm slower than a gt3076 in my experience and the powerband is more linear.
I wouldn't run any higher than 9:1 compression on a high hp turbocharged engine.

[jonnyc]

Soon changed your mind about the gt35!  
gt3582 spools 500rpm slower than a gt3076 in my experience and the powerband is more linear.
I wouldn't run any higher than 9:1 compression on a high hp turbocharged engine.

It was always something that I was thinking about.. The real question is how long will I stick with the 3076 lol..

Just depends how fast it really is, I want it to be fast.. If that means a 35r then thats what its going to have lol.. I would never go any bigger than that on a 2.0L though..

There is a 35r Audi A3 in the states that Revo have tuned, in fact, the guy who owns the car works for Revo.. He made 650WHP recently, and he's going for 700WHP shortly.. He's still running a FWD chassis at the moment but is sticking a quattro running gear in it to rein in the power..

Apparently they can only do logs in 5th gear hahaha..

[Ryan_Evo]

The GT3076R is a decent turbo and for a all-round street turbo i think it's one if not the best but they have there limitations as far as 1/4 times etc.IMO on pump fuel they will not do 10's.You need a gt3582 or bigger to get into 10's but it's still not that easy!
I tend to ignore all the yanks to be honest they tend to use dynojet's which overread massively and there 1/4's seem so optimistic.I personally like the delivery of the gt30 compared to the gt35.

[jonnyc]

The GT3076R is a decent turbo and for a all-round street turbo i think it's one if not the best but they have there limitations as far as 1/4 times etc.IMO on pump fuel they will not do 10's.You need a gt3582 or bigger to get into 10's but it's still not that easy!
I tend to ignore all the yanks to be honest they tend to use dynojet's which overread massively and there 1/4's seem so optimistic.I personally like the delivery of the gt30 compared to the gt35.

Im going to see how I get on and go from there.. Its all down the line anyways, just nice to know I have the option of an easy upgrade in the future..

[Ryan_Evo]

Your a bit like one of my mates jonny he had a gt3076 made 500bhp took off within 2 weeks and had a gt35 on.Personally i like my 500bhp hybrid ,i know it will never do better than 11's but imo drives alot nicer than his gt35 although 50bhp down.
When's that turbo turning up?

[jonnyc]

Your a bit like one of my mates jonny he had a gt3076 made 500bhp took off within 2 weeks and had a gt35 on.Personally i like my 500bhp hybrid ,i know it will never do better than 11's but imo drives alot nicer than his gt35 although 50bhp down.
When's that turbo turning up?

haha.. I wander how many times you have told me that I wont get into the 10's?? lol.. Seriously mate, its a goal, something that im going to work to, its a bit of fun and nothing more. I appreciate your opinions but I dont have short term memory loss  

Turbo is on its way, so its down to shipping and customs now, fingers crossed within a week, then all being well a few days to get it all back together! 

[Ryan_Evo]

Sorry to bang on about the 10's  To give you some hope another lad did 10.9 with a gt3082 at 129mph but his car was extremely light and about 580bhp,so there is still hope.Anyway i'm coming down when you go to pod give you some proper competition 

[jonnyc]

Sorry to bang on about the 10's  To give you some hope another lad did 10.9 with a gt3082 at 129mph but his car was extremely light and about 580bhp,so there is still hope.Anyway i'm coming down when you go to pod give you some proper competition 

Thanks lol.. Think ill be having a few practice runs so I know what im letting myself in for haha..

Should have pics of the turbo kit tomorrow all being well. BSH are sending me a load of stuff later today! 

[DanGB]

Dont know how you can live with lag of a Gt35, I think the 2871R is more than enough lag as it is.