I am not new to Rx-7's. I have had three. My first was an 86 GXL which had close to 250,000 miles on it. my second Rx-7 was a base model fd which I loved. I had a 99 front bumper on her and she was beautiful. But after my accident I had to get rid of her. Such a sad day. Anyway, I now have a 87 Turbo 2 and I am having problems with her. My first problem is that the gas mileage is horrible. Not much has been done to the car except the removal of the cats, front mount intercooler and a better intake. Dont ask me about the intercooler or the intake because it was on the car before I got it. My second problem is with the tires the rear seems very slick while going around corners and while trying to get a good launch from a stop. I know what you are all going to say. you are going to say get better tires but the thing is is that I have had these kinds of tires before and never had this problem. could it be that the tires are bigger in the back. The tire sizes are 205/55 front and 225/50 in the rear. could this be the problem or could I still use the same sizes when I get new tires. Someone please help me. Sorry for this being so long I just wanted to give you the specifics.

 

Paragraphs.. good...

umm.. so what do you want help with? Something about the tires? or the intercooler?

Or did you already sell the car, and that's why you're saying "goodbye" to mileage (?) and tire trouble?

Sorry.. maybe I'm being too picky right now..

 

Bad tire grip in the rear and just horrible gas mileage

 

sorry should have double checked how I typed it.

 

And yes I still have the car. There is no way I would sell it.

 

Tires - How much pressure are you running in the rears is a big deal with 225's.
Have you noticed if the inside part of the tread is wearing faster than the outside?
Too much pressure & the footprint is reduced by the negative camber, and traction goes to ****.

I run 27 PSI in 225/50's in the back.

 

Even wear. and the tire pressure is 32 P.S.I.

 

but the funny thing is that the lower the pressure is the slicker it gets

 

The poor mileage can be due to many factors - probably more than one.
Lots of driving around under boost.
Worn out plugs.
Wworn out or mis-adjusted TPS (the ECU dosen't see closed throttle, so no deceleration fuel cut.)
Someone stealing your gas.
Fuel management way rich from any or all of the following:
Bad temp sensors (water & air)
Oversized or leaky injectors
A fuel leak somewhere
Boost leak

 

And I would also like to know if there is a glitch in 87's wiring because the passenger window will not go up no matter what i do. Sounds silly but I have cheked the wiring, motor, fuse and I even changed the window switch.

 

That is strange.
What tire brand & road surface /conditions are you working with?

 

someone stealing your gas hahahahha at least you put most options in there but yeah that would suck

 

Your tires could just be old, rotted and hard if they were put on by the previous owner.

 

car has only 52,000 miles on it and has rarely been driven by previous owner. And I don't drive it that much.

 

For the passengers window, did you check out the lock window switch on the drivers side?

 

Maybe check the driver's side safety switch & connector.

The body electrical manual is at the link in my sig.
Download & print what you need.

 

Tire brand is cooper cobras which I have never had a problem with before. And road conditions are great when I drive. I never drive on really bumpy or horribly paved roads

 

Yes I checked the driver side lock and still nothing.

 

I'm thinking cold pavement, sand or salt residue after a melt, paint stripes, oil film, old patched asphault, putting down power on an off-camber surface, good surface but just left a wet or sandy area, even just making more power in the cold air than you're used to.

 

Could be. So what tire are the best for twisty and hilly roads.

 

one thing though. I went through a right hairpin turn at about 25 M.P.H's and the tail stepped out on me. I didn't have to counter steer but it was still to slick for that speed. I did not push the throttle in much either. And the road was well traveled.

 

I have cooper cobras on my NA for the all season tires, they are hard all season tires and do not grip well. I spin through 1st and a little bit into second when going hard from a stop, and the *** slides around turns with very little throttle (the LSD makes this worse)

The treadwear on the ones I have is like 450, I've done so many donuts and burnouts it's ridiculous and there is still a ton of tread left.

One thing worth mentioning about the cooper cobras however, when you heat them up alot they stick like crazy. Otherwise, they are pretty crappy tires.

You might also want to check your dtss bushings, maybe install the rear steer eliminators available from racing beat. If I have traction issues with these tires in my non turbo fc, you must be having a hell of a time. Although, my NA has more power than a stock t2, not sure what mods you have, may not be a good comparison.

 

My t2 can keep up with stock fd's. Thanks for the info on coopers.

 

something else thats strange about my t2 mine did not come with power steering.

 

What's horrible gas mileage? 16 mpg? 8 mpg? I've heard plenty of TII's getting ~16mpg.. even though I think that's horrible. One guy's horrible gas mileage (~8mpg?) was due to a leaky gas tank!

Wider tires in the rear could help traction, if the sidewall is stiff enough.. too sloppy a sidewall (cooper cobras?) might make a wider tire worse in cornering (given the same size rim).. especially at lower tire pressures. Your shocks could actually also be contributing to poor launching and cornering grip, as well as possibly bushings/alignment...

My passenger side window is slow to come up.. haven't bothered with looking at it yet.. can't help there.