Tuning my 07 sti (manual) 0-100?

[PtPixel]

Totally identical, then VF52 will win.

VF52 has same bottom end as VF46, but has better compressor efficiency in the top end.

[Robbks]

depends how long the race is.

if it's an 1/16 mile track (100m) I'd put my cash on the VF46
1/8 mile would probably be very even
but 1/4 mile the VF52 should sh!t all over it

Currently here in Tassie our drag strip is only 1/8 mile.
MurfB4 on here is pushing 350 ATW and running around ~7.8sec to 1/8 mile

Brent who's got a gen 1 lib pushing 420ATW is only just quicker over the same distance, 7.6@93MPH
Both running 6 speeds and similar weights (Brent's Gen1 has a full cage, etc)

But over the full 1/4, the big HP will just pull away.

[PtPixel]

Dyno differences between VF46 & VF52:

http://legacygt.com/forums/showthread.php/spool-study-between-vf46-and-vf52-198675.html

Torque differences between the two turbos (since on identical cars) comes down to pure acceleration. VF52 is accelerating better than the VF46.
Yes this a 3rd gear pull on a dyno, so not truly applicable to the 0-100 time, but similarities will still remain for lower gears.

[owen]

Ok lets take all the science out of it and let me ask a simple question.

If 2 identical liberty's had a drag race, one had a VF46 turbo, tbe and tune, the other had a VF52, tbe and same type of tune.... which would win?

For arguments sake lets say both cars were tuned by matt (kido) as he would be the best to answer this as hes getting the results out of the VF46.

From 0-100 it would be bloody close. In 3rd would be where the vf52 started to pull away. Very very slowly

[PtPixel]

Interestingly this shows differences between VF40(basically the same as VF46, just an earlier revision) and VF52. VF40 is showing earlier torque but lower peak torque - Might have something to say for VF46 over short quick distances.


That much of a difference at the beginning makes me thing the two dyno pulls were started at different rpms though...

[Robbks]

Lower peak torque because it's running lower boost

[peadya100]

Hey gus. Page 1 of my profile shows vf46 vs vf52 on my car if you want an exact comparison.

Ok, that pretty much answers all my questions then... thanks guys!

[PtPixel]

Lower peak torque because it's running lower boost

Both ran the same peak boost and used the exact same ramp rate for spool up which is locked in shootout mode.

Adam - so it does, shows about the same

[<GB>]

depends how long the race is.

if it's an 1/16 mile track (100m) I'd put my cash on the VF46
1/8 mile would probably be very even
but 1/4 mile the VF52 should sh!t all over it

Currently here in Tassie our drag strip is only 1/8 mile.
MurfB4 on here is pushing 350 ATW and running around ~7.8sec to 1/8 mile

Brent who's got a gen 1 lib pushing 420ATW is only just quicker over the same distance, 7.6@93MPH
Both running 6 speeds and similar weights (Brent's Gen1 has a full cage, etc)

But over the full 1/4, the big HP will just pull away.

looking at the dyno graph pictured id still say a 52 will beat a 46 at 100m drag

but if Justin drove the 52 and owen drove the 46 id say owen would win ha ha same driver though the 52 would win

[bigBADbenny]

My experience of having a casual 0-100-ish drag race with Bruce's lib confirms for me that there is not alot between the VF46 and VF52 under 100kph.
Bugger all given my wag is heavier than Bruces sedan and he only began to pull away as we passed 100 or thereabouts.

I'm sure Bruce can recall the exact details of where he pulled away, IIRC toward the top of third gear...

Me: VF46 3" TBE and pump and tune 170ish atw...
Bru: VF52 plus the above, headers, injectors intake etc 200ish atw...

[owen]

I'd beat Justin only if I didn't miss shift 2nd. My car hates flat shifts into 2nd.
2/3 times it just won't go in so I've stopped trying. 0-100 is no fun..my turbo doesn't really come alive until 100kmh anyway.

[alexeiwoody]

Take a look at a vf46 vs vf52 dyno graph

THIS is your problem.
A Dyno only allows the car to accelerate as fast as the dyno operator programs in.
As has been said above by other knowlegible people, "non-linear" acceleration tells you the complete story.

I don't have a problem, just not sure how to get through to people who won't listen?

You're exactly right, except we're talking about a vf46 vs 52, not a td04 vs td05. I've raced a vf52 lib on the 46, and if I was to describe it - it looked like I kept up, but at close inspection he probably won by a metre. That was to 90km. And no our cars were not identical twins, so yes it could have been down to anything. But to say the vf52 is slower to a 100...nah I imagine he had a decent tune too considering I was kido tuned at the time and still got beat

[owen]

My experience of having a casual 0-100-ish drag race with Bruce's lib confirms for me that there is not alot between the VF46 and VF52 under 100kph.
Bugger all given my wag is heavier than Bruces sedan and he only began to pull away as we passed 100 or thereabouts.

I'm sure Bruce can recall the exact details of where he pulled away, IIRC toward the top of third gear...

Me: VF46 3" TBE and pump and tune 170ish atw...
Bru: VF52 plus the above, headers, injectors intake etc 200ish atw...

Way to end the thread Benny!

[<GB>]

I'd beat Justin only if I didn't miss shift 2nd. My car hates flat shifts into 2nd.
2/3 times it just won't go in so I've stopped trying. 0-100 is no fun..my turbo doesn't really come alive until 100kmh anyway.

I cant get 3rd need a pitch stop mount and better gearbox mounts, when I was at the drags most runs I had that issue which wouldn't help with times..

I know what you mean when you say doesn't come alive till high speed though I do remember being beside bruce and he had me by a car length till I grabbed second and flew past ha ha my car does ok beside these small turbo cars the autos might be a little different cause they can stall and I just take off fast not rev it up and dump the clutch

[bigBADbenny]

If there was a stock replacement turbo that was more responsive 0-100 than a VF46 or VF52... I'd like to know.

BNR 16G: http://legacygt.com/forums/showthread.p ... 54172.html

Any other contenders?