LAT

I have a 97 RUF CTR-2 that I have been having an overboost problem with and have been working making various changes to try to solve the problem. The overboost is still there and I will be checking the wastegate lines next. However one interesting result came from changing the Air Mass Sensor.

My car did not like lower gears and the throttle felt heavy and abrupt when used in first or second gears. The idle was not smooth and it was not the easiest starting. SInce the change in the AMS, its like wow. The car starts without hesitation, purrs at idle and the throttle response is like haven taken 100 lbs off the flywheel.

The AMS are available from your dealer, however if you like to save a couple of bucks you can do what I did. I purchased a BOSCH OEM unit for $380. vs the $800. for the Porsche unit. The Bosch part number B3130-128512

Here is the link to one supplier, others are available.
http://replacement.autopartswarehous...Air+Mass+Meter

Good luck


LAT

Kevin

I recommend that all 993TT replace there MAF's if they haven't done so..

K24madness

Also the primary O2 sensors as well.

Long term fuel trim is calculated off of the primary O2's.

fc-racer

Lat, did you get my email response to your questions? Please let me know if you want me to re-send.

dbf73

Kevin - you're talking about doing this on the basis of age rather than mileage and even if the car runs great?

LAT

fc-racer, yes I did thanks, I will be testing the wastegates on the weekend.
Much appreciated.

LAT

K24madness

LAT.... if all checks out PM me...... I have a solution that will retain your stock frequency valve but eliminates boost spikes.

I can provide pictures and instructions

MOD500

How easy is it to change the MAF, DIY or dealer job at next service?

Thanks



Martyn.

LAT

MOD500. on the CTR-2 all I had to do is remove the airbox and it is right there. I think it took me about an hour to an hour and half total. I would rate it a 4 out of 10 for difficulty.

PM if you have any issues, I will try to help.

Good luck.

LAT

tlark

https://rennlist.com/forums/showthre...ht=INTERCOOLER

Pic #2 next to the air box on its left

Pic #9 in greater detail.

Have at it, its no problem...

LAT

K24madness,

When you say primary O2 sensor, I assume you mean the pre cat one, please confirm.

What do you notice after the change in the way the motor runs?

Tahnks

LAT

K24madness

Yes the ones closer to the turbos. The function of the primary O2 sensors is to monitor exhaust gases. This information is used by the DME to adjust long term fuel trim. If you have a OBD2 scanner you should be able to see that number. The problem is that as O2's age they become lazy and don't respond as quickly. The results is improper fuel ratios during the closed loop portion of driving. During WOT it does not matter. Secondary O2's are only there to measure catalist performance. They do not affect fuel trim.

LAT

Would a OBD2 scanner inform me as to whether or not they a responding properly?

LAT

K24madness

The only way to accuratly look at a O2 sensor is with a O scope. The OBD2 program is to slow.

A 10 year old car with 25,000+ miles is a good canidate for preventive maintenace in this area.

LAT

Then my 97 with almost 36,000 miles is going to get new ones.

Thanks