Hey, I've got an 89 n/a. The high end power (6500-8000) Really sucks. At the moment, I've determined that the VDI system is working properly (it moves and opens at the right rpm), and my actuators are open from 3000 rpm and up. Are there any other systems that up high end power on the car that could be broken? Could low compression be to blame? The car has 146000 miles, but feels pretty strong. Also, if I do a compression test, what kind of compression is "good"?

could be compression, anywhere above 90 is good, but excellent is above 125. vacuum leaks cuz power loss also.

Hmmm...my first guess was a cat, but that's not the case. My TII had a problem with high end power when there was air in the cooling system.

wow how would that affect power??? hmm interesting.....

I think it was kinda overheating when the boost was up there...trust me, it took RD and me forever to figure out the problem!



I wonder if the stock knock sensor was retarding the timing or something.

crazy ****. i believe you sometimes the simplest **** can upset everthing. So how did you get rid of the air?

The bleeder valve...it was stripped, so I hadn't been bleeding the air out (after having a coolant leak) but after that, we crammed a screwdriver in there to get it out. You'd think I would have just bought the $7 part. https://www.nopistons.com/forums/pub...#>/biggrin.png



Not all TIIs have the bleeder...I think it may be different for S4s and S5s, but I'm not sure. I just know that 1revin7's TII doesn't have one.

Its hard to say why youd have bad top end power with your mods. You sure your 6 ports are working? Only other thing I can suggest is make sure everythings tuned up i.e. plugs, fuel filter etc......

Maybe it's because you have an N/A. https://www.nopistons.com/forums/pub...#>/biggrin.png



I wonder why people think we TII owners are assholes. https://www.nopistons.com/forums/pub...DIR#>/wink.png I am probably buying an N/A soon, so don't go thinking I don't like them.

where is this bleeder valve??/

The one in front of the AFM on the radiator elbow.

maybe thats why i don;t know about it i have the k2rd radiator.

Yeah, it's probably only on the stock radiator.

my guess is clogged cat(s).

Check your leading coil. Make sure it's firing. If the lead coil is not working you will loose alot of power. Check your trailing coils too, take a look at your spark plugs.

i have the same issue and it was the o2 sensor......i grubbed a motec wideband and it showed me that the o2 sensor was old and tired. Remeber 13B/12A exhaust is much hotter than piston engine exhaust

my cats are laying on the floor in my garage.

FYI rx7.com has o2 sensor for like $40, i replaced mine last year.

I thought it was in open loop under WOT, that would render o2 sensor irrelevant.

mine too, but what about that performance cat u have?