How to tell if turbo makes boost

[Wiese]

Hi:

I am looking to purchase a 931 and I have done a lot of reading on this board and elsewhere what to look for and check on the car. One of the things that baffles me is how to make sure that the car makes boost.

The car I am looking at has no boost gauge. I would suspect that around 2800/3000 you should feel a significant power increase, but since I have never driven a 931, I don't know what exactly to expect.

Can the experts out here enlighten me. 951 owners please join in as well!

Thanks,

[pcelenta]

you will hear the turbo spooling and feel it kick in. head on over to the 924board. org site...whole section on 931 tech. lots of gurrus. Warning...931s are addictive! I have a 79 euro project and just picked up a 1980 "S"

[kcoyle]

If there is a bit of "on/off" feeling when you punch the gas pedal then one can assume the turbo is working. If you punch the gas and nothing happens then something is amiss. As stated you will hear the turbo wind up and you might hear some sort of audible "clack" when you let off the gas abruptly as the recirc valve closes. These aren't the quickest cars out there so don't expect to be blown back into your seat. Good luck and check the toofah board often.

[931GT]

Also the turbo "whistle" on the 931 is quite loud, you will hear it if the turbo is spinning up properly. In stock form the US spec 931 uses only about 6.5psi of boost, so the power surge shouldn't be dramatic but it will be noticeable.

[Wiese]

Thanks for everybody's feedback, I appreciate it!

Looks like with cat-bypass and a slightly higher boost the 931 could be brought close to euro spec hp.

I will let you know how it goes.

Cheers,
Kay

[emoore924]

The suggestion to post over on 924.org is a good one. The car you're considering may already be known to board members as there are several active in the V,BC area...

[rick13]

The main way I tell if my turbo is working is when I reach about 4000 rpm my back wheels start spinning and smoking. She gets real tough to steer too!

[Rasta Monsta]

You'll know. Without boost, a US turbo is probably only putting down 70-80 horse, double that with boost.

[931GT]

Originally Posted by Wiese

Thanks for everybody's feedback, I appreciate it!

Looks like with cat-bypass and a slightly higher boost the 931 could be brought close to euro spec hp.

I will let you know how it goes.

Cheers,
Kay

If it still has the original cat its likely already self by-passed. With a US 931, assuming the engine is in good nick and its not on its original HG, you just need to buy a boost gauge and a MBC and turn the boost up to 10psi to get Euro spec hp (you'll need to use premium gas though). I imagine the primary reasons for the lower boost level on the US car was to ensure safe engine operation on 87 octane gas and to keep its performance down compared to the 911SC.

[Tervuren]

Drive a 944, get a feel for the acceleration. If the 931 doesn't match it when on boost, you've got work on your hands. They both should be around 140-160HP.

[Wiese]

Again, thanks to everybody's input. I am going to see the car tonight and let you know how it goes.

[Wiese]

Hi:

After a 11 hour trip to Vancouver Island (return) I am the proud new owner of a 1980 931. My DD is still parked at the Ferry terminal, but now I am enjoying driving around in the Turbo. I love the "whistle".

I will probably start a new thread soon with pics (once I have it cleaned up a bit). Now I am thinking first service items:

- Oil and filter change
- Coolant system flush, new thermostat (running to cold)
- Replace timing belt
- detail the entire car
- fix some interior trim

Now the fun starts!

Cheers,
Kay

[kcoyle]

Originally Posted by Wiese

- Replace timing belt

Do this first as these are interference engines.

Also, make sure the fan switch and thermostat are matching temps.
http://www.924board.org/viewtopic.php?t=30809&view=next&sid=12017cdb5675674cb03f4726bba1fc8b
http://garage.ideola.com/prod-CoolingSystemKits.html

And congratulations.