I've owned a stock 93 R1 since 1996 when I bought it from the original owner with 4000 miles on it. It now has 30,000 trouble free miles. I recently upgraded the car with a Racing Beat catback, Pettit downpipe,TKT cold air intake and pulley kit, AST, boost gauge, boost orifice kit, and Pettit grounding kit. Also Koni Sports. Car runs strong.
I've searched the forum, learned alot, but can't seem to find this exact problem: Under acceleration, I get the sick whoosh noise which seems and sounds to be pressure bleeding off. It then abruptly stops as if a valve has closed and I get a pressure spike to 14-15psi, then right back to around 10 psi. It seems to be timed on it's own. By that I mean you can reduce throttle to ease boost but the duration of the phenomenon is about the same. BOV? Under hard acceleation, boost is about 12-8-10 with the exception of the spike. Steady hard pulling in 5th gear is about 9.5-10 psi right up to top speed. Sure would like to get rid of that sick sound. What would be my next step?

 

check for boost leaks. its possible that your line to the recirculating valve is clogged and keeping it open until high boost. check the line and the valve.

 

Stock ecu?!?!

 

Thanks, and yes, stock ecu.

 

when i opened my intake and exhuast up with three inch i got some boost creep and a little detenation at high rpms i put he stock catback back on and it quit then my o2 sensor started to go out and it began runnign rich lazy me i have not fixed it yet but he extra gas fixed the boost creep even thoguh i get like 8 miles a gallon now.... i would try mixing premium gas with race gas if anyone sells around you the extra octane stopped my boost creeop on race days try that

 

Punctuation is your friend.

As far as your problem goes Propturner, do you have any rpm readings when your car does this? My initial thought it that you're getting a big boost spike right after transition.

Basically the whooshing sound is the secondary turbo spooling like crazy because of the huge increase in exhaust flow, and as soon as the CCV allows the secondary turbo to add boost to the intake track you get a massive spike. The boost then goes back down because the ECU fully opens the wastegate to control it. Thats just a guess though.

Check out this site for lots of good turbo trouble-shooting info: http://www.autosportracetech.com/RX-...leshooting.htm

 

You are taking this to top speed with your mods on a stock ECU and boost issues?...I dont know about you but I would be shitting my pants. Maybe the boost spike is like 911GT said with the secondary turbo kicking in but kicking in too strong with that new airflow you gave it?

 

You need to get a boost controller ASAP and set it to 10psi before you blow your engine. Keep off the throttle till you do. All you need is part throttle to spike to 15+ psi and blow the motor.

Read the newbie stickers and you will find that this car will blow an engine very quickly running that kind of boost on a stock ECU.

The only thing keeping your motor from blowing right now is the boost leak. Its likely the couplers between the various turbo and intercooler pipes. Replace with new silicon couplers and clamps from hosetechniques.com.

 

I don't think Pettit would sell me a kit that's going to blow my engine right away. Remember, steady boost is 10 psi, right on the money. This pressure spike I get is literally a fraction of a second. A very fast blip of the gauge. I made one top speed run just to test. Boost was rock steady at 9.5-10psi in fifth. Only on acceleration runs near transition, does this happen. This whooshing sound, cutoff/pressure spike even happens at part throttle. You can pretty much control the spike pressure with your foot. Worst cast is 15 psi at full throttle. For now, I just take it easy and don't allow it to spike over 10 psi. Once the whooshing sound stops, you can accelerate hard and not go over 10 psi. I think 911GT2's explanation is closest to what I'm experiencing. I will be getting a boost controller and upgraded ECU in the future but I'd like to know what I'm experiencing. Is this super quick blip still dangerous?

 

It is still pretty dangerous. If it detonates even once you have a good chance of blowing an apex seal. I'd stay out of the boost until you can get a boost controller. You don't necessarily need a new ECU as long as you can keep it at 10psi, so stick with a controller if money's tight.

 

what he said!

 

One important lesson to learn about buying after market "performance parts" aka mods is that people will sell you anything whether or not it works as described or works well in conjunction with other parts.

 

Thanks guys, point taken. I'd rather do it right. Boost controller, then an ECU. Recommendations?

 

Greddy Profec B, then A'PEXi PowerFC.

 

Or if you dont want to spend a billion dollars on a boost controller, heres the one I swear by.

http://www.turboxs.com/standard_boost_controller.htm

 

Is this a spring type?

 

Can't go wrong with the Profec. Power FC is far and away the best ECU available right now, but it's also expensive, and I only say it's the best because there are not nearly as many tuners for other ECU's like the Haltech, or AEM EMS.