i have an S5 GTU, and one of my biggest issue with it is the 5th gear...

when i shift into 5th at about 100+ (according to my semi-off spedo) the tach just drops from 8000 to near the 4-5k area and it stops accelerating. Is this just my car or is this the case for all those of this model. If its always true, i wonder if i could swap 5th gear from a different model so it was a useable gear, instead of just for crusing?

Thank you

 

semi off speedo? how fast are you actually going? i usually shift into 5th at about 65MPH


what i want to know is if you shift at a lower RPM does it still have the same problem or only once it hits 100?

 

not certain, but i think gtu's have different gear ratios than other na models, could just be the 88 model (i read it somewhere).... but if its true, then just swap trannys.......

note, could someone verify my info please...... im like 80% sure

 

Why would u need this? Wow, 8k in 4th isnt like 100. more like 140ish.

 

gear ratios can be found in the Standard features and options sticky thread (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/specifications-what-did-2nd-generation-rx-7-come-w-options-standard-features-249616/) at the top of this section.

 

thanks icemark, ill give that a look over.

the speedo is off due to 18" wheels on the car, im not sure how greatly that throws it off...but i think it may be significant

 

well, from what that said... the only 5-speed na that had a different gear ratio was the 1988 convertible ... and it was just a different 5th gear

 

depends on the tire size...... but it wont be off more than a few miles an hour at most, if at all!!

 

well i thought some of the FCs had a speed governor or is that only the import models?

 

^ is that true? i would be very curious to know.

 

hmm... i dont think the wheels would slow the car down/throw off the speedo THAT much, think there is something wrong with my car?

 

uhm, no.
I'm pretty sure GTUs had a different 5th gear

 

i thought gtuS only had a different rear end......i think their tranny is the same as the NA....am i wrong?...the ring and pinion is what gives it the 4000rpm in 5th=80mph

 

Question is where/why are you shifting into 5th at over 100?

 

hes a racer.....

 

what track near boston lets rx7's out at over 120mph?

 

the onramp

 

Why would you want 5th gear to be much for anything but cruising? 4th gear gets you going fast and can maintain that speed all the way up to our NA top speed of 139.

My car goes 80 at 3000 rpm in 5th. The gtuS rear end is built for more acceleration at ¿4.35? instead of 4.1 and therefore should give you slightly more accel ability in 5th

 

well, the 5th gear i think is to keep you up there. 5th gear has no power,. if you shift into 5th, and unch it, it tops out at around the 100 mph barior. its hard to get past it. but if you downshift and gun it to redline, then upshift, you can get to like 140. i know i waspissed off at this. maybee cus our transmitions suck.

 

The GTUs has a different rear ratio; 4.3:1 instead of 4.1:1
I belive the GTUs transmission also has different gear ratios.
However, he doesnt have a "GTUs", he stated "GTU"

5th gear is an overdrive gear here, so it is ONLY good for high speed fuel economy, it is too hard for the engine to push it to get any decent acceleration out of it.

 

Ekkk nothing like throwing away 10-15 HP by using 18" wheels...

 

lol. ironic that the na 5th gear would suit the tII better and the tII 5th gear would suit na better:P

 

Ah man you guys are clueless... I posted the link... you all could have looked for yourselves:

86-87.5 non turbo coupe 5th gear: .711
87.5-91 non turbo coupe 5th gear: .697
87-88 Turbo 5th gear: .762
89-91 Turbo 5th gear: .719
88 convertible 5th gear: .711
89-92 non turbo convertible 5th gear: .697
89-90 GTUs 5th gear: .697

 

i was right.......GTUs has the same NA tranny.......only the rearend is different........

ps...dont flame me..

 

so you're saying its possible to ride 4th all the way to 130+?