nuclearfishin

So I just finished cleaning both mafs and when I took the car out, I was getting some detonation on hard acceleration. I give up, it's time to take the car in again!

TT Surgeon

Detonations usually means tune is bad or your afr are f'd up, your car is pulling timing to save the motor.
Check everything, get rid of the ipd, put the stock one back on with all it's hardware.
GL
C

elite1

Plugs and Coils were changed last summer. How many miles have you put on your car since?

nuclearfishin

maybe 3000 miles, if that.

nuclearfishin

Lol, you might be right but I'm not willing to abandon ship yet (but it's getting close). When I'm not a Porsche factory driver I'm a professor of systems engineering in my real job, so I definitely understand the system of systems effect. I don't believe it's the IPD per se, but could definitely be related to 1. the tune after adding the plenum, 2. bumping hoses or connections after installing, 3. unknown damage to a part while making multiple changes/upgrades, 4. unrelated issue to plenum/upgrades, 5. other mods affecting plenum performance, 6. worn parts/connections, 7. higher boost from tune exposing other weakness in system, 8. etc, etc, etc.

nuclearfishin

This is unbelievable but I finally think you're right. I pulled the y-pipe and went back to stock (still have ipd plenum on). The difference was immediate -- car IAT is down 15 degrees, and boost pressure went from a max of 8 psi to 18 psi in 3rd gear pull. Check out the data log in my other thread. It's hard to believe a y-pipe could make such a difference. BTW, the y-pipe was not IPD brand, it was another I'd rather not say.

volv4life

Sounds like a boost leak under pressure then maybe? Would explain why the vacuum test checked out.

Team Plutonium

Damn! Glad you found the culprit, I did not expected that. When you switched back to stock did you use new seals and clamps or the same ones? If yes, I'm trying to figure out what the hell is going in with the y-pipe unless it is a serious flaw in the design itself, which I have such a hard time to accept how anybody can screw that one up. Why not say which brand? It's the price vendors pay for selling these things and promoting and promising more power. They are sponsors for a reason since they are using this forum/platform selling their products; I see nothing wrong with disclosing that information.

CincyScott

I don't get why they don't seem to work either, but it seems to be proven out quite a bit. Maybe someone can enlighten us all?

ctony66

Was it a plastic Y pipe? Maybe it's split along a seem or something and leaking only under boost. If not it wouldn't explain a loss of 10lbs of boost otherwise. Besides you had the pipe on when you made good boost before.

Team Plutonium

There is a lot of chatter across forums from folks who say they lose power with that mod, mostly mid-range, yet this is all "butt-dyno" talk, I have yet to see actual data that supports these claims. But there is a lot of actual hard data out there that supports the numbers regarding power gains. I've seen actual dyno runs before and after, and I've seen improvement on the track... hp gain translated directly into trapping 5mph more in quarter and half mile events.

I'm not discounting what others experienced, but I would love to see some real data that supports the notion that many lose power with that mod.

I agree with the poster above me, I find it hard to believe that you'd lose 10 pounds of boost all of a sudden without any damage in that pipe.

nuclearfishin

The reason I haven't mentioned the brand is because I actually don't know, I bought it off somebody here in the marketplace (it's not one of the more common brands). Anyhow, the pipe feels like aluminum and it's not cracked or anything, but since I've started troubleshooting the power issue I've been feeling the pipe and after one run it's hot as hell. When I switched back to the factory y-pipe, I can make runs all day and the pipe might get warm, but never hot. That got me thinking about my earlier good runs, I went online and checked the weather and temps were in the mid-50's compared to the 90's last week. I'm thinking maybe the cooler temps kept the engine and y-pipe cooler when I had those good runs earlier in the year. Otherwise I have no idea.

ctony66

I can see heat soak being a problem but don't understand why it would drop boost. Your sig say's you have champion intercooler and those are all aluminum. Are they getting really hot also? You should bring the pipe with you to the track and try swapping it between runs. At least then you will know if your problem is solved or there is an intermittent problem.