Boost levels for S4 turbocharger

[Riddlemr2]

I've done some searching, but haven't had much luck figuring out what boost pressure would be safe for the stock s4 turbocharger. I'm basically trying to decide between chip 4 and 5. I'd be pretty surprised to hear that it wasn't out of its efficiency range above 1.1bar. I will be supplementing the boost with larger injectors and already have an upgraded fuel pump and open exhaust.

A friend with an Elise SC beat me (barely) on the highway last week and that's just not cool...time for more boost!

Thanks!

[esprits4de]

No matter what you do, get a HKS boost controller! Best I have ever done......

[greekmix]

Dave

I have done this work testing almost all chips available with the stock turbo before I replave to the improved ball bearing unit.

My advice is that if your turbo is healty dont change it!!!!

If all work good with your car you should get the power you are after for up to 10 seconds defore the temp catches up with the unit.

If you have changed the fuel pump and the secondary injectors you can go to chip #6 red hot otherwise go for the #5.

I have done dyno many runs on my car with all these mods stage by stage which you can view at www.lotusesprit.com.au .. if you need more help please email me and good luck!

PS: to produce the power you should have every part of the car should be working 100% dont just blame the turbo.

Some times I wish I had my original unit back since the responce was fantastic as per the dyno runs !!!

Edited March 14, 2009 by greekmixS4

[DBredS4]

I have the no6 chip and whilst I have upgraded primary and secondaries I have the stock fuel pump. I have also changed the cc pump for an electric one so won't have to worry about impeller fins falling apart.

Who supplies the upgraded fuel pump?

[lotus4s]

DB, the stock fuel pump is more than ample for the #6 chip.

[Riddlemr2]

I have the no6 chip and whilst I have upgraded primary and secondaries I have the stock fuel pump. I have also changed the cc pump for an electric one so won't have to worry about impeller fins falling apart.

Who supplies the upgraded fuel pump?

The fuel pump is a Sport 300 unit.

I'm looking for a setup that can survive a track day so I was trying to decide between chip 4 and 5. I want more power, but I don't want to detonate the engine...will it handle the 1.2 bar of boost on a regular basis? Wouldn't that much boost be borderline outside of the turbo's efficiency zone?

[Jonathan]

Doing a lot of research on this atm. Currently my conclusions are keep your old chip or at least upgrade the code.

I'm still struggling with the concept of 1.2 bar esp since the MAP sensor cannot read that high !

This lends the car to operate in open loop mode and thats not good imo.

I did try and discuss this here :

http://www.lotusespritforum.com/forums/ind...showtopic=22420

My current thought is to chip the car and increase the boost slightly to 1.1 bar.

As stated though above if the chargecooler isn't tip top the MAT rises so fast that the power you gain is only

I'm also concerned about how the chips cover the wastegate solenoid which seems to be a lot different to the standard code - instead of feeding the boost in, the chips I have seen just open the solenoid full blast which will accelerate the turbo visciously which may lead to this amazing feel of power.

That said I have seen 1989 SE turbos hold 285bhp dynod for years on end with chips in them...id like to kniow more before i shell out what is a large amount of cash for an eprom.

Everyone has commented on the smoothness which can't be a bad thing, thats what I am interested in sampling.

[esprits4de]

Jonathan,

I still have a bunch of 3.0 bar sensors lying around from my testing, adjusting the voltage levels should get you to your desired reading capabilities...

If you want one for testing....there are some verry good reads on this in the cyclone/typhoon forums.....got to look..