as SOME may know i just went through some BS to get my car back on the road and one of the tall orders was to get another trans. ok so i ordered a 95-99 transmission...this is where my question takes place...

if memory serves me correctly, when traveling at 70mph on my old trans (2000) i thought i was turning just under 3K rpms, now with the new transmission (1995-1999) i'm turning almost 3200 rpms....can anyone confirm that the 95-99 have a shorter gear ratio? my MPG hasnt been affected, i'm still getting the same gas mileage, just curious as to the RPMs.

and please to anyone with anything that is NOT contributing to this thread, you can easily hit the back button or 'X' at the top of the screen as you did to click into this thread. this is a legitamite question.

thanks in advance

 

Somethings not right. I have a 4th gen tranny too and at about 3200rpms in 5th gear I'm at about 80mph. The gear ratios should be the same for each transmission. Somethin isnt correct at all. Where did you get the tranny from?

 

thats kind of what i remember my old transmission doing as well. i mean my MPG is not suffering.

i got it from a place out of Opa Locka, FL..close to miami. it bolted up no problems. i didnt know if it was because of the mating of a 95-99 trans to a 00 engine (wierd thought, but its what i thought) could the lightweight flywheel be a culprit to make it turn that high a RPM?

 

5th doing 80mph at 32000 rpm sounds about right... i dont think you have a problem.

 

lol wow @ 32000 rpm lol jk i know what you mean...

but yea i'm doing 70 turning 3200 rpm..

 

I'm not the one with the problem...

 

Lightweight flywheel should not cause that. The only thing i can think of is that the tranny was rebuilt with a different final drive or 5th gear. I dont know why that would be though?

How are the rest of the gears? do they seem to be spinning at their normal rpm in relation to speed?

 

i cant really say...i never really paid attention to any other gears but my cruising gear, because i based that on my gas mileage, and i cant say that they are shorter persay right now because its revving quicker because of the lighter flywheel, so i'd probably be wrong to say that they are short...

what other 5th gear is available? btw this trans looked untouched as far as being rebuilt is concerned..

 

is the gas mileage worse too? maybe it's just a difference on how the rpms are displayed. I think analog Tachs aren't 100% accurate anyways. If I compare my VAFC rpm with my tach's for example there is a slight discrepancy

 

no as i mentioned my mpg arent/havent been affected. for soem reason, it seems a little better as i got 391/tank, 24mpg on the first tank i've been through since i've put mileage on it.

i was thinking the display may be off as well...i havent tried redlining yet since i've done all of this to see if it tachs out more or less.

 

Also for the RPM difference between Essential1 and phatboislim:

Couldn't that be because you guys are running different wheel sizes? Smaller wheels = more revolutions at the wheel = higher engine rpm as well

 

i've always run just under 3k at 70 mph...g35 18s to the 19s i have now...but now i'm running about 3200 @ 70mph

 

That can also affect engine speed vs. actual speed, but if the same overall diameter is the same it shouldnt make a difference. But even if that was the case, it still wont explain why his is different after just a tranny and flywheel change.

 

only thing that made sense was the fourth gen 5 speed trans has shorter gears, or as you said essential, possibly the trans was rebuilt with a different final gear..but when the trans came in it looked like a totally used transmission untouched....dirty and grimy on the inside, but absolutely clean on the inside.

 

That's true, I just thought right about 200rpms might be insignificant, especially since the MPG hasn't changed... I remember reading somewhere how some peoples' rev limiter would kick in at different rpms. As in different numbers on different people's tach even tho the ECU limits all at the same spot. And that was explained with the tach's inaccuracy.

If your RPMs were really higher, your MPG would drop.
If your gears were shorter, you would have higher RPMs.

If your gears were shorter, your MPG would drop.

 

yea its not a huge concern, but if the 4th gen trans has shorter gears, that'd be an extra jump for acceleration...maybe someone can eventually chime in on this

 

I am 98% positive that the gear ratios are the same between the 5th gen 5 speed and 4th gen 5 speed. Hence my car has a 4th gen tranny.

 

i gotcha

 

i probably could have saved a little bandwidth by google searching earlier, but i'm sure this will be 'helpful' to someone else with teh same/similar question...as you said, it is the same gear ratio according to this website:

http://www.vibratesoftware.com/html_...nsmissions.htm

so..i guess its down to 'why would it be @ 3200?'

oh well, whatever. MPG is the same thanks essential and scuba steve lol

 

No problem man, but that still doesnt solve the mystery of the high reving maxima. lol


Do you have a way of logging the actual RPM other that the stock tack? safc? scon tool? other?

 

lol, naw i sure dont, only way i have is the stock tach....i dont have any tuning apparatus right now...hopefully the beginning of next year i will start to get some tuning goodies as i start collecting some other things.

 

Unless equipped with a GPS for verification, it wouldn't make a difference since the speedometer will be off by the same margin since the VSS/RPM relation is always the same for the same car, etc.

So in theory the the RPM/MPH relation on the dash will ALWAYS be the same, even if the speed is off due to smaller tires.

 

So hypothetically speaking. could it be that Essential1 has lower RPMs because he's putting out way more power, thus the engine has to work less hard to drive a certain speed?

 

Not really.

This will only be true if the OPs clutch was bad. Meaning if he pushes the gas pedal while in gear, the rpms will flare up a little, but it should NOT hold if i'm not mistaken. I've never driven a manual car with a bad clutch though so I dont wanna say this as a fact.

Maybe someone else can chime in?

 

I see that makes sense.

No problem, but please call me by my full name.

I'm Connor McSteve, of the Clan of the McSteves. I've been alive for four-and-a-half centuries... I am... immortal....

 

ok...scuba steve aka Conner LOL.

but all of my stuff is new...new stage 1 clutch, lightweight flywheel...so no slippage or nothing at all. so this one maybe a good mystery forever. i'm not mad at it...just have to get use to seeing my rpms where its at. since i'm not losing MPG i'm not going to make a big deal of it

 

Nope.
Crankshaft to the "rubber on the road" is a solid connection, once the clutch is engaged.

The throttle might be open a bit less, though, but the rpm's will be the same.

If the engine was spinning 200 rpm's high because of clutch slipping, it wouldn't be doing for long....that clutch would just smoke itself to death.

 

Yep, mechanical relation cannot be changed unless by a perfect constant slipping (highly unlikely, and even more so unlikely to be linear throughout all the gears). The only way it can be changed is obviously by an FD &/or single forward gear change.

3.823 is the FD for the A32 / A33 5MT's IIRC.

 

am i reading this wrong?

http://www.vibratesoftware.com/html_...ons.htm#Maxima

seems like its 0.759 is the final drive for the 5mt...

 

That's the 5th gear ratio, not the final drive.


http://www.vibratesoftware.com/html_...les.htm#Altima

 

oh! i'm not too savvy on gear ratios/drives

 

Wait a minute...

Nmex in a thread about manual transmissions?

 

Yeah, I've done a lot of soul searching on my A32 re: swap, etc. And comparing different ratios for even the A34 5AT..

http://forums.maxima.org/5th-generat...s-5a-5-5g.html

 

ohhh...so this may mean that i have a 98 or 99 transmission amirite?

 

http://forums.maxima.org/3261761-post2.html

Honestly one of my favorite posts of all time.

 

Off-topic but somehow related: Would Suprastick take care of TCM compatability issues with the 5AT?

 

As in eliminate the electronics headache if one were thinking of swapping? I don’t think so, since the SS does not have a 5AT option, from what I remember.


I had so many spreadsheets with all kinds of different cars, and would ‘pick’ my ‘races’ that way back in the day, as in I knew with respect to my dyno, where the sweet spot was.

Although, it was theoretical and on unloaded tires (as the tire flexes with speed, etc, the diameter will change by a factor dictated by temperature, )

 

It doesnt. And the 5AT wouldn't be a good idea for those of us with extended rev limits either. Even in the tiptronic mode if you try to hold the gear past the redline, it will still force the shift at the stock redline... I think that thread was on the NYCmaxima forums. I dont recall exactly where I saw it though.

blah blah blah is correct. lol