Guys seriously and this is no joke. I have a STOCK ported 12A 166,000 mile engine in my 1985 GSL RX7, with a semi-stock ( a bit ported and tuned) 79 nikki, 79 ported intake, holley FPR, A/F ratio gauge, fuel press gauge, double sheave alt pulley, cheap *** headers (home made), carter fuel pump, 2.5" freeflowing exhaust ( no presilencer) to a superturbo Dynomax, stock clutch disc, stronger engaging press. plate., stripped storage bins, no spare tire, jack or insulation.

I got done tunning most of the carb, and the fuel pressure, still need to tune high RPM WOT throttle.

My problem is although I CANNOT be over 150hp with this settup (or can I?) I cannot get the tires to hook up...I am running 215/50/13 with an appropiate wheel size on all four corners. I just bought two discontinued but new 215/50/13 for the rear, they are yokohomas 352 with a 200 treadwear...I thought these were going to be a lot better than the Proxes FZ4 (crappy all weather) I'm running in the front, but again I get no traction even on 3rd...car is tail happy when I shift to third...yeap it's impressive to my friends but I just feel it's just wrong. I just don't know I feel very bad with this, I have another set of wheels, 15 inchers and I am considering stepping up to some DOT drag radials when I change the diff. to higher gears.

Does anybody have this kind of problem? any good tires you recommend. I need some good DOT tires with really soft compound.

If I can't get this car to grip as it is, then it's going to be undriveable when I slap in the bridge ported engine.

 

Put more weight back in the rear of the car

Dunno man Im lost there, my problem always was cant get it to SPIN

 

Well I'm going to move the battery to the rear soon, but still that is not the problem...i had another rx7 which was streetported and I never had this problem and I had euro t/a on panasports and they were like 185/50 or something like that and that car was well over 190hp, that car felt really stable at any speed.

I just feel there is something wrong with this car. Maybe the car has the rear differential housing off axis or something??? could that be it? maybe it was wrecked and the whole geometry is off...damn it I just don't know.

 

that definatly does not sound right.. try throwing some sand bags in the back, or some extra wheels or soemthing... but my guess would be that something is definatly wrong..

does it only happen when you are hard on the throttle, or all the time.

 

hard on the throttle...maybe I'm a freaking magician and this thing is puttin more than 150hp!

I'll thy that extra wheels idea...I'll put them side by side like the dually trucks. J/K lol!!!

 

duallies rule!!!!!!!!!!!!!!1

 

i meant in the back for added weight, but i am sure that you know that..

those tires should handle a hell of a lot over 150hp. plus i somewhat doubt that you are pulling that much to the wheels... i would say that there is definatly something worng.... check the axle, diff, what not.

 

i wounder if you could fit duallies if you had a wide body kit on there..

 

The Tire profile (50) is too low, and is making you actual gearing even lower.

Try a 60 series tire on the rear for a couple of passes.

Also, make sure the rear tires aren't overinflated.

 

You keep refering to this as a problem, many of us here see this as a blessing!!!!!!!!

If you feel that the car is unstable due to power availiable put on a stock Nikki on it, stick a potato in the exhaust, or learn how to drive. If you feel the car is unstable due to syspension geometry, or the frame being twisted, you need to take it to a body shop that has the ability to check/straiten the frame.

But judging by your last post, and reading what you told us you have,I think you blowing smoke out of your ***.

 

man, back off, that was brutal Seriously, people come here to find answers to questions, not get flamed by people like you. Sit back, relax, and count from 10 backwards...

Jeff

 

maybe there is something wrong with the wheel bearing/diff/axle on one side and only the other side turns or something??

 

moremazda I'm serious man...it's no joke man... but I don't take your post as a flame...you are right 100% with what you say. I think is the geometry. But I also think the tires I'm using are just not cutting it, like a combination of both.

I got a set of 15" wheels with some cheap tires too...same thing. I'm going to borrow a set of tires I just spoke to a friend of mine. If it helps then problem fixed. If it doesn't then it's off to the alignment shop and I'll do a complete check on the suspension...

if that also doesn't help...then I stick a potatoe not in the exhaust but up my *** and try to f*rt and then I'll hang myself...LOL!!!!

 

Direct freak 50 serie on a 215 tire is still pretty tall...so back to point A. Also same prob with 205/50 15" although with bad tire.

 

Not really. The 50 series has very little flex, and is great for cornering, but sux for draggin'

 

Check all your rear end components. if a trailing arm or the watts link is bent, or a bushing is really really bad, it could lead to problems at the backend, although my first guess is tires.

 

Here's a good question that's no one's asked yet? Are you spinning one tire or both? Could be the rear end.

 

I can lay 2 5 foot black strips if I drop the clutch at 4000+ and nail it.
But right now it has stealy 13s with 165 80 13s of a brand I have never heard of. They really suck.

But i can drift like a madman with them. THey dont seam to wear at all.

 

Stiff sidewalls = no traction

215/50s will suck.

Stiff suspension = no traction

What kind of suspension do you have?

Old tires = no traction

I know you said they are "new", but how long were they sitting on a shelf somewhere before you bought them? I bought the last set of 205-60-13 Eagle STs in Ohio. I had a "NEW" set of them on my T-bird and the grip was excellent. However the set I put on the RX-7 was more like excrement! I looked at the date codes - the tires were made sometime in the 80's and had sat on a shelf for about 10 years. During that time they got hard as hockey pucks. No traction. Fun to drive, of course

 

I got the stock suspension in the rear even to the stock coils and old bushings.

Funny you mention that, I think I just bought a pile of excrement too and installed in the rear.

Yeap peejay I'll do that...I'll check the manufacturing code. They were factory wraped and air sealed but who knows they might be bad too, they look nice though. But the Proxes were new although 50 series too... we'll see thanks for the tips guys, really appreciate your help.

 

Yayarx7 and myrxbad I'll check the rear today and also if it's spinning only one tire most of the time. I suspect it is somewhere along those lines. Could a bad bearing like mentioned before do that? I have another complete housing assembly so I might just switch them.

The links are all straight. None bent.

How can I check for a bad bearing?

Is the disc rear end any better than the drums one I got drums now? the other one (disc) is from an old 80 rx with rear discs. I know the diff. flange is going to be different. I got the brake lines and everything to do the swap.

 

Um, does the rear happen to kick to one side???

You might have a worn LSD and are only spinning 1 tire i had a problem like this on my 79 with a 83 LSD diff..


-Zach

 

Zach yeap exactly...humm everything is leading to the rear end. I'll check it out thanks man!!! I don't even know if it's LSD but yeap it kicks to one side all the time.

 

mperformance,
I'm glad you didn't take my last post as a flame, it was not ment to be one. If you have drums you probably don't have an LSD. Put the rear-end in the air, spin one tire if the other spins in the same direction you have LSD, if the other wheel spins oposite you have the standard open diff.

This experiment could reveal a lot about your car you didn't know. In your first post you said the car an '84 GSL. GSL's came with rear discs. That is the resaon they are called GSL. You said in your previous post that you have drums in the back. Drums only came on S and GS models. If you have drums on your GSL, some body went through a lot of trouble to put the lesser of the rear ends availiableon your car. Drums = open diff. If both of your wheels spin in the same direction with this experiment, somebody installed an LSD into your standard rear-end, ??????????????

Also with your "problem", do you leave two black marks on the pavement or just one ?

Ryan

 

moremazda

hummm....well my car is an 85 GSL and yeap it has rear drums. It is a GSL because it has power everything, even power steering. Anyhow if it's suppose to come with disc then something is fishy with it. Maybe the previous rear went and they had it replaced with whatever they found in this case drums.

I couldn't take out the car today because it was raining so I can't really test it out, but I will...don't you guys worry I'll get that problem fixed. Anyhow I thank you all, you answered all my questions I'm very happy and glad you guys are there to help out.