I do not experience the issue. Not with the lower gears, TC, and now SC. Just curious as to why some run into the problem while others do not and possibly come up with a answer to assist others.
Lee

 

Well I'm glad you are not, cause I think a lot of people claim to have this problem with their SC cars.

I hope it stays that way for you, but that's why I previously asked if you have relatively fresh Tranny and diffy fluids. (Say, Under 20k in milage). This may not be the root cause of other peoples bounce problems, but it could be a contributing factor.

 

Morris was responding to Mr Johnson's post.

He's also pondering between getting wheels and getting a LSD.

I have the problem with my RMM SC, stock gears, 18" wheels, brand new valve body upgrade, TRD LSD, 2800 stall TC. I'm out of town and don't know my tire sizes off the top of head. Lots of fresh fluid, including when I did the valve body (same time the SC was installed)

I did not have the problem before the RMM SC.

 

I am pretty good with my fluid changes. Oil once a month,coolant once a year, rear end every 6 months, and trans every year (entire flush) so that could be why my SC car is still running solid even with over 120k miles on it. Quick, I need some wood. I was a bit worried as even RMM said I would hit that rev limiter for sure with the lower gears. Just curious as to why some do and others do not. Fluid change could be one of the answers.
Lee

 

if i have to guess i would guess you have 275/35/18 in the back?

 

This is kinda off topic, but Lee, when will you get a chance to dyno your car? The SRT ECU is installed and tuned already?

It's not good to hear that Dave is seeing the problem and he has fresh fluids, but now I'm looking at the HP differences between your two cars.

So work with me here. I'm thinking that the more HP from an SC, the more tendency to bounce since the engine would rev up quicker. At a certain point (i.e. HP/ TQ level), the tranny can't react quick enough to complete the shift before hitting redline. If Lee's car has less power than Dave, he may not experience the problem "yet". Not an expert here just thinking out loud. Experts please feel free to chime in.

We really need to examine all the similarities / differences between both your cars to figure this one out. Your set ups are very similar, so identifying the differences and examining how they could affect the bounce problem will be the key.

Also for Dave, switching over to the Amsoil Synthetic Tranny Fluid may be a tad more slippery than the Toyota fluids. If you are on the edge of bouncing, this may help. Could be worth a try at your next flush interval. I've seen a recommendation on the Ford forums to switch to Redline synthetic on the manual tranny Ford Probes. Apparently this was the fix for rough shifting in the older high milage cars. So I thought it was worth a try, even though it's a different application, to see if it will fix the bounce issue.

 

You make a very good point and one that I have been throwing around in the back of my head as well. I have now placed several hundered miles on the car and receive very little pinging-the same as pre S/C-,so it ,"appears" to be running well. I should have time next week to dyno the car and check the a/f ratio. I just need to find someone here in So Ca that can dyno the GS in 4th if possible.
Lee

 

We've had local dyno shops do our cars in 4th vs 3rd. The differences were negligible, but since you are running FI, it wouldn't hurt to do a few runs in each gear.

Never know what you'll find out.

Look forward to seeing some numbers from you soon.

 

Sorry just thinking out loud

The thing kwith the LSD is
I can get a complete unit with 3.76 gears for 650 plus about 2 hours in labor to install, or try it myself even.

Or I can do an LSD Unit I think it was about 1000.00 plust 700 ini labor to remove my gears from the stock carrier and then install them in teh new LSD unti and then reinstall the whole thing back into my car.


The other thing is I thought only FI cars were having the rev limiter bouncve problem. Its internesteing to note that NA cars are having the problem also.

 

When buying used, make sure you are buying a True LSD, because they did make rear ends with the 3.76 gear but NO LSD.

So this means you would have an LSD and would have stock gearing, not the 3.76 . Are you sure that is what you want to do? Unless you are planning to go FI, I would go for the 3.76.


Good point. This is why I am interested in this thread since Pearlpower has an SC and does not bounce.

 

I got in on JPI's group buy for the TI PC at a lower 2600 stall than my current one and with a turbo stator pump, when I have that put in I'll switch to the Amsoil Synthetic. However, if all goes well and the problem is fixed, we won't be able to tell if it was the stall speed or the extra lube . That's a situation I hope I'm in.

Morris already has FI (RMM SC)

 

RMMGS4, I already have the blower, thats when I started having the bounce issues. I am currently with the stock rearend. I didnt have the problme untill I put the blower on.

As far as the LSD, that is the whole issue, I dont know what I want to do. I dont want to make the rev bounce issue worse by going with the 3.76 gears. But I dont want to pay twice as much for an LSD where I will have to use my stock gears.

I have heard that line pressuer in the tranny from increased HP causes the problme but I dont think anyone at this point really knows, at least I havent heard a definitive answer.

What I need to know is does the problem get worse with the taller gears or will it stay at the same level that I see now.

Better yet what causes teh problem and how do we fix it.

Franknly from the responses here, I dont think wheel size makes a difference with this problem, it seems to happen to guys like me with the stock 17's on up to guys with 18 and 19's


DAve, I had the 2800rpm converter before teh blower and I didnt have any issues with rev limiter problems. So I am not all togetehr sure that it is relatged to TC either.

 

OK, I compiled the data above from the responses and listed them below to find a common denominator. Please correct in the same format for easier reading if I listed something in error.

HITS AND STAYS AT REV LIMITER-REQUIRES FOOT OFF GAS TO SHIFT
klynchgs4 -stock gearing, PI TC, tire diameter+2.08% over, RMM supercharger 2.87 pulley year-1998 model
morris-stock gears, 2800rpm TC,tire diameter-stock-0%, RMM supercharger 2.87 pulley,1998 model
Mr Johnson-stock gears, stock TC, tire diameter .99% over, SRT supercharger, SRT valve body, 2000 model
DaveGS4-stock gears/TRD LSD, 2800 TC, unknown tire size, RMM supercharger, 2.87 pulley, valve body,

NO HIT-CAR SHIFTS INTO NEXT GEAR AT WOT.
Pealpower-LSD/3.76 gears, Stock TC ,tire diameter-.09% over, RMM supercharger 3.12 pulley, 1998 model
RMMGS4-LSC/3.76 gears, RMM TC,tire diameter .67% over, RMM valve body, 1998 model

I have an appointment Monday at SP Engineering for a dyno. Anyone is welcome to attend.

 

One clarification, I occasionally hit the rev limiter and after a moment it will shift up, when I do hit it. It also only occurs when at WOT

 

OK, I compiled the data above from the responses and listed them below to find a common denominator. Please correct in the same format for easier reading if I listed something in error.

HITS AND STAYS AT REV LIMITER-REQUIRES FOOT OFF GAS TO SHIFT
klynchgs4 -stock gearing, PI TC, tire diameter+2.08% over, RMM supercharger 2.87 pulley year-1998 model
morris-stock gears, 2800rpm TC,tire diameter-stock-0%, RMM supercharger 2.87 pulley,1998 model-occasionally hits rev limiter
Mr Johnson-stock gears, stock TC, tire diameter .99% over, SRT supercharger, SRT valve body, 2000 model
DaveGS4-stock gears/TRD LSD, 2800 TC, unknown tire size, RMM supercharger, 2.87 pulley, valve body,

NO HIT-CAR SHIFTS INTO NEXT GEAR AT WOT.
Pealpower-LSD/3.76 gears, Stock TC ,tire diameter-.09% over, RMM supercharger 3.12 pulley, 1998 model
RMMGS4-LSD/3.76 gears, RMM TC,tire diameter .67% over, RMM valve body, 1998 model

I have an appointment Monday at SP Engineering for a dyno. Anyone is welcome to attend.