Extra Power?

[Chrisuk]

Hello and thankyou for taking the time to read my question, I am having a full rebuild being carried out on my engine, (964 3.6 Turbo 1993).
Whilst the work is being carried out, and the guys have it in bits and ordering loads of parts, something suddenly sprung to mind.
I thought I remembered reading someone saying that if I were to put a different boost spring in my Turbo that I would get more power output, is this correct, if so, what spring would I need please?
Many thanks Chris

[Cobalt]

Originally Posted by Chrisuk

Hello and thankyou for taking the time to read my question, I am having a full rebuild being carried out on my engine, (964 3.6 Turbo 1993).
Whilst the work is being carried out, and the guys have it in bits and ordering loads of parts, something suddenly sprung to mind.
I thought I remembered reading someone saying that if I were to put a different boost spring in my Turbo that I would get more power output, is this correct, if so, what spring would I need please?
Many thanks Chris

Chris,

Yes you can gain more power with a 1.0 bar spring, although many of us have gone a bit further.

I have B&B headers, rear muffler delete (G pipe), HF K27 turbo and 1 bar spring. I am seeing 365 hp to the wheels or about 430 BHP. If you really want to improve the car eliminate the cat or go with a 100 cell cat to help the turbo spool up faster.

[Chrisuk]

Hi Anthony,
Thankyou for that, that's the sort of advice / answer that I was looking for, not major works but little tweaks, Is it easy to replace the spring for example? also do you know what bar spring I have in the turbo at present, many thanks, Chris

[Cobalt]

Originally Posted by Chrisuk

Hi Anthony,
Thankyou for that, that's the sort of advice / answer that I was looking for, not major works but little tweaks, Is it easy to replace the spring for example? also do you know what bar spring I have in the turbo at present, many thanks, Chris

The 3.6's had slightly higher boost than the 3.3's. There is a tolerance on the springs and we have found that although spring might be rated at one opening pressure or another it doesn't necessarily work at the designed pressure. So the 3.6's are within spec between 7.9 and 8.5 bar. Even thoughthe gage only reads up to .7 bar.

There is a TSB about this that reads as follows:

TSB. Number 9032 9307.

Concern: The boost gauge in 1994 911 Turbos will only read 0.7 bar at max boost

General Information The boost pressure for 1994 3.6 liter 911 turbos is .79 to .85 bar. 1994 911 Turbos are equipped with a boost gauge that is only capable of registering 0.7 bar. For technical reasons, the software for the boost pressure gauge was taken from the 3.3 liter 911 Turbo.

Should a 1994 3.6 Liter 911 Turbo have a customer complaint or "car will only reach 0.7 bar boost," the complaint must be verified and boost pressure must be checked before repairs are performed.

If boost pressure is within specifications, no repairs are necessary.

Repair Information: 1994 3.6 Liter Turbo Max boost 0.79 to 0.85 bar 1992 3.3 Liter Turbo Max boost 0.75 to 0.81 bar

[Chrisuk]

Hi Anthony, I understand better now thankyou!
Is the Spring a Porsche part, or do I order it from somewhere else?
Is it easy to change it? Do you know?
Kind regards Chris

[Cobalt]

Most performance shops have them they run around $65.00. You cantry Stephen from IA, I believe Pelican sells them also.

Not too difficult to install although it depends on the condition of the nuts and bolts. There is a lot of heat in the exhaust and it causes binding, rusting and scaling of the hardware.

For less than an hour job you might want your shop to do it just because they have the lifts and tools. You want to be careful not to damage the diaphragm and you should have it tested afterwards, preferably on a dyno to make sure your not over boosting.

Good luck