On my 87 TII with a 90 Turbo setup, I get great pull from 3000rpm to 6000rpm, but then between 6500-7000rpm there isn't much pull. It feels like the car isn't going anywhere or at least very slowly...like if your revving in the redline zone type thing. Is that because my car might be running too rich in that zone or my turbo is running out of juice?

 

Your peak HP is at 6500 ish and starts to drop off

your peak torque is 3500 ish and thats why it feels so strong from 3000 ish to 6000 ish

 

you need to get a more high flow system and run some more boost if you want peak power at 7500-8000 12psi should cut it with a free flow system, but then you need upgraded injectors, exhaust, intake, fuel pump and fuel computer (or full ECu)

so you would probably be better off living with what it gives ya...but at least get rid of the precats with a downpipe or something.

 

Haha, I didn't know I was going out of my power range at that point, I thought something might be wrong! Should I be shifting earlier like at 6500 or 6800rpm, instead of redlining it in every gear? Actually I just updated my SIG, so as you can see, I've already done a lot of the stuff that you recommended. Its probably from me sticking in another straight through muffler into my midpipe to quiet the car down, it was so damn loud before, probably cut down my high end power!

 

I had the exact problem your are describing when I first bought my car. It felt like almost no power at those revs! When I got rid of the cats it helped things alot, but it did not completely go away. When I did the ATF trick the problem seemed to go away completely. Although there is still a bit less power past the power peak, it still buries the redline! I guess it's possible that carbon deposits were hindering the speed at which my engine could rev....i dunno just a theory.....

-Brian

 

Eh Brian,

That MAKES TOTAL SENSE! My car always runs RICH right now and also before I put in this slightly used Mazda Block into my car, it was in another RX7 that had 3000kms on that brand new motor and my installer told me that the engine had a lot of carbon in it from the old guy that never REVVED the engine. I'm going to try your ATF suggestion and see if that frees up some more POWER up there!

 

#1, you've got a 2" downpipe and have your boost controller set to 12 psi ..you're creating boost with not enough exhaust flow.. all you are going to be doing is heating up your intake charge.. and I'm sure you know what will happen when you do that.. chances are a car making 10psi but has a 3" downpipe will have more power then you at 12psi with cooler intake charge

#2, you're running a 160 degree thermostat, which is waaay to cold for your motor.. stock is 195.. if you want to go cooler go with a 180 .. at 160 your motor will be running too cold which leads up to decreased fuel mileage and excessive carbon buildup.. you're wondering why you are running rich and chances are it's because you arn't even reaching operating temperature (or not doing so fast enough) the waterthermo sensor behind your fill neck has alot to do with how much fuel you are dumping into your motor.. if it sees that your motor is not up to proper operating temp, then it will make you run richer (cold motor requires more fuel etc..)

 

Oh crap! I'm in dying need of a 3 inch Downpipe!!! Where can I pick one up cheap?

 

I believe Racing Beat sells a 3'' downpipe $100 bucks. They only list a 2.5" downpipe on their website so you'll have to give them a call. My racing beat turbo-back has a 3" downpipe, but it will not bolt up the same with other exhaust pieces.

http://www.racingbeat.com

I'd take care of these problems soon... it sounds like you are heading towards eventual engine failure... BTW, my car had 71k original miles on it when I bought it and the owner had babied the car, which is why I did the ATF trick. Hope everything works out for you

-Brian

 

Thanks guys, so Priority #1 would be to do the ATF trick and then change my DP to 3 inch, that should help great I hope!

 

Your priority shoudl be to swap out that thermostat..
I know you prolly won't do it because it doesn't sound like a "go faster" mod like the downpipe is.. but hay, if you really want to head towards a 4th motor, then you go right ahead and do whatever you please...

 

My n/a was doing that, except instead of the acceleration slowing, it completely stopped at 7500 RPM's. I would hit 6500 and the car would stumble, slow, and the hit 7500 and stop accelerating, real annoying.

First thing was spark plugs and a fuel filter, which didn't noticeably do a damn thing. Then, because I couldn't think of anything else, I ran a bottle of fuel system treatment on 3/8 tank of gas and ran the **** out of it to get the secondary injectors cleaned up.

That did the trick, runs like a champ now. I think the problem is that the car had been sitting for a couple months before I had bought it and it gummed up a few things. It would really be in my best interests to do the ATF thing soon, but I've been a tad lazy.

 

I was having the same problem, turns out that the hose for the 6 ports was disconected from the plastic valve/solenoid.

Rosh, Listen to Chris rg it makes sense whathe's saying!!