I had questions and worries about the size of the 'hot side" piping on the Turbonetics kit when I was installign my kit. I have an '05 RevUp engine which likes to rev. I had previously installed the MREV2 w/ spacer which gave me lots more torque but still allowed the engine to rev.

Now , with the Turbo kit installed, it seems to be choking by about 5500 rpm. The engine just doesn't like to climb the rpms any more and it sounds like the piping between the engine and the turbo are choking the engine. ....and I have a 3" to dual 2.5" exhaust that's much more efficient than a stock exhaust.

I am thinking of putting the stock plenum back on to see what difference that might make.......

Has anyone looked into trying to make larger pipes going to the turbo? Maybe venting the wastegate to atmosphere might relieve some of the choke point?

any thoughts?

 

Its probably your engine tune running too rich at 5500. The TN piping will flow plenty.

 

Im assuming you made the standard TN kit fit the Revup-nice to see somebody else doing that. My friends TN Revup also with an MREV2(++) kit falls off nasty up top as well, its a big fall after 6200rpm's much more so than stock. He hasnt tried the standard lower plenum again though. Give it a shot and report back man...

What EM do you run? Injectors?

 

I've got a UTEC w/Tuner and 550 DeatschWerks Injectors.

 

What are your AFRs like?

 

They are around 11:1...a little higher in some spots, a little lower in others.

 

Im guessing the car has been tuned? Its possible the revup's flow more needing more boost. Torque seems like its peaking early, giivng the impression of 'falling on its face'. I used to experience this on my civic. It would fall flat on its face above 5000rpm on 6psi, but with 10psi it pounded all the way to 7500.

Cam's can help this problem out. I doubt the piping is being outflowed though - they use 2.5" stock dont they? What about boost, does it fall off uptop?

 

no...you have both sides of the engine feeding into a pipe that is at best 2" ID, followed by the turbo - which is definately an impediment in the airflow path.

Existing the turbo is no problem. They have a 2.5" pipe increasing to a 3" pipe. after that I have a reverse Y-pipe feeding dual 2.5" all the way back.

 

Larger pipes = a decrease in exhaust gas velocity.

You have other issues with your car. I had 410rwhp whiach is about 40 more than the stock TN kit and I have no issues like you describe.

JET

 

Lets see your dyno sheet.

And, the last time I checked, I had a full 3" downpipe.

What do you mean it "sounds" like its choking the engine?

 

andrew, i think you do have the mrev stuff still installed, maybe alberto is right and need to throw the stock lower plenum on??

 

Jet,

at what RPM were you making peak power?

 

Craig,

The downpipe doesn't go up to 3" until downpipe#3.

 

The power with stock cams on the non-rev up motor peak @ 6250 RPM.

JET

 

between the motor and turbo probably isn't choking, you might have a leak, where the piping isn't perfectly aligned. I've got a few like that and I have a weird issue that I think is related to it.....so i'll be aligning those pipes this weekend to see if it helps, as well as installing some new spark plugs and an air filter.

 

What is your timing values at that load point? You may need to run a bit more timing there...

 

Part of the challenge is what Mia alluded to above. On pump gas, we are very restricted in the amounts of timing we can run up top. With retarded timing in the top end, it will be impossible to make power to redline with any of these kits on pump gas. You guys might recall about a year ago, when I ran C116 on my car, and made power all the way to 7000rpm and power was still building. 22 degrees of timing will do that! but on a high boost car running pump gas, we run almost half of that. We also want the engine to have good longevity too.

 

i have been running 14- 15 peak tq timing at 13.5 psi and 18-19 peak rpm timing at that same psi with no knock ever and no issues....


i always have 93 with some 100 octane mixed in, i alternate every time i get gas pretty much...

i will take some timing out for sure when i turn it up though..

 

Not everyone gets 93 octane

 

Indeed.

My power peaks around 5500-5600rpms. I've always attributed this to the fact that I'm running the reflash and can't pull timing up top, like others have mentioned. Right now my car runs out of steam a little on the top end. I've seen mostly midrange improvements. I believe with tuning and a fuel system I could pull another 20whp out of the car safely, and that would mostly be on the top end.