35thSLP

Does anyone have any ideas on how to improve throttle response on an stock 951? anyway to improve low end torque as well. I don't need a drag car but a little more would be good. Thanks!

Dal Heger

Hmm, let me think...

8.0:1 compression ratio...
2.5l 4-cyl engine. . . .
Tall gearing . . . .

Nope. Gotta wait for the boost, then hang on!

It's never going to have the throttle response of your v-8 engine. It just can't. But wait until it gets on boost. It's really easy to keep it on a boil if you want to.

Off the line, there is nothing you can do without SERIOUSLY abusing/breaking (expensive) components.

Dal.

Jason_86_951

The best you can do is lower your turbo's spool-up.
A set of good chips and a manual boost controller is a good start. Get a boost controller that has a drain like the Accuboost, then you can delete the cycling valve.
These alone will drop your spool-up time by a bit.
From there a test-pipe, better flowing intercooler, Tial wastegate and a quick spool turbo will get you closer, but will never equal the off the line push you get from a v-8.
Hope that helps,
Jason

theedge

I second the better boost controller. My EBC made an amazing difference.

Im actually in the process of going several steps further too, lightened flywheel, KEP aluminum pressure plate, increasing the compression ratio via milling the head (should help a tad), plus other work like valve griding, and ceramic coating the exhaust headers and crossover pipe. Theres also a Tial going in. Eventually ill get more serious about weightloss (on the car and its driver ), ive already stripped out the power steering junk. The lightweight flywheel makes a nice difference, I drove an MR2 Turbo with one and it felt really I dunno... "Alive" down low.

Keep in mind that the turbo, its piping, and the intercooler, plus the longer air filter tract, all slows down the throttle response compared to an N/A car.

pikey7

Bi-turbo.......

theedge

Pffffffffffffffff screw that...



TWIN CHARGED!

pikey7

Oh oh, SUPER-TURBO CHARGED!......

Seriously, a better wastegate, more efficient turbo, EBC, light flywheel, A/C delete, manual steering conversion and MAF/MAP help a lot. Anything to take the load off the engine will help. (then you may as well pay for a SUPER-TURBO CHARGER!!! (j/k) )

Eyal 951

I have milled my head (theedge, pm me if you want some info since your doing it) for more compression, along with some nice radiused and back cut valves. I notice a difference right there. The head is also ported, among other things.
Other the chips, mbc, exhaust, i dont have much more. but this stuff wakes it up a bit earlier, along with a bit more when not under boost.
~Eyal

DanG

I've brought this idea up over on the turbo board before, but I dunno if anyone has tried it yet. I don't have a 951 to try it on myself. Once I get one, I will try it out.

Cheap and easy anti-lag device


Its worked well for turbo dodge guys, the theory carries over to all turbo cars. If there is ever any negative pressure differential between IC-TB pipe and just after the MAF sensor, then this WILL improve your spool-up times. The cycling valve has a significant amount of resistance to this direction of flow, based on the fact the air has to push the valve open against the spring force before anything gets by it. No, I'm not claiming this is a miracle part. But I do believe it can have positive effects on throttle response and spool-up times (or bring full boost on at a lower rpm).

theedge

And Eyal, YGPM

Eyal 951

Dan, you got more info?
~Eyal

DanG

This is the thread from the turbo board (or just click the picture in that first post)...

https://rennlist.com/forums/showthread.php?t=143308

theedge

Hey Eyal youre over your PM limit.

mroberts

My friend used to swear by his pre-cat exhaust cut out. Now he swears because he got ticketed for a noise violation