RPM really high at 55mph ? GSX 2G

[GSX95AWD]

Cruising down the highway in 5th gear, doing 55, the rpms are right at 3k. Every other car i drive the rpms are around 2400~ or so. What would cause this, or is this just average for DSM's ?

 

[jrohner]

Have you verified that your speedometer is correct?

 

[ChiTownHussla]

are all the dsm 5th gears the same? how bout final drive gear?

 

[Calan]

are all the dsm 5th gears the same? how bout final drive gear?

Tranny gear ratios for DSMs

DSM EVOIII GEAR RATIOS EVO III gear ratio comparison
What Gear Set Do You Have?
2G DSM Transmission Differences

The rear end ratio is the same from 1990-1999 -- the difference is in the gear ratio of the transfer case of 1990-1996 vs. 1997-1999, and the 58-tooth front diff ring gear in 1990-1996 vs. the 57-tooth front diff ring gear in 1997-1999 transmissions.

 

[AngelOfPassion]

Have you verified that your speedometer is correct?

I was wondering this also. I feel like this could be gauge related. Either the RPM gauge not reading correctly or the MPH gauge not reading correctly...

As far as the cause, I'm not sure...

 

[nuclearr]

At 70mph I run 3300RPM

 

[TSIflyer95]

Just called my buddy with a gsx. He runs almost 4k at 80mph in fifth. 3k at 55-60 is not that high.

 

[DSMTyson]

check for boos leaks. i bought a gsx with very bad boos leakage and in 5th geari couldent go any faster than 60 with rpms at 6500. fixed the boos leak and tada!

Could it be bad wheel bearings? Frozen caliper?

Are you guys serious? Wow, just... wow.

OP. There's nothing wrong with your car. That's normal. Verify your actual speed with a GPS. I know my speedometer is about 3 MPH off at 75 MPH. Look into getting an Evo 3 5th gear whenever you end up rebuilding your trans.

 

[crash89]

Sounds pretty normal to me.. The only difference Ive noticed is the FWD to AWD 5th gears.. My FWD was just a bit lower RPM than my AWD.. 60 mph is right about ~3k rpm

 

[flawlessTSI]

That is rite. Your speedo may be off by a few mph due to wheel size or what not.

Side note. I drove my friends 2000 ss camaro 6 speed and at 100 mph in 6th gear the rpms were at 1800ish.

 

[Funfettie]

EVO gear line FTW! shep stage 4 also FTW. 2650rpm at 65 i believe, havnt driven her enough since the rebuild to remember exactly. Haha

 

[ChrisMgst]

Well considering your driving 2.0 liter which is known to be able to rev high. Those numbers to me seem fine.

 

[Black95TSIawd]

Try driving an Evo X. I was at 3700rpm in 5th at 65mph.

 

[NHerron]

It's pretty normal for little engines to run that high. Kinda the same idea as how we make power in the high RPM's whereas V-8's make it down low.

I also seem to recall having read a taller 5th gear will do nothing significant for MPG's. Something about 3kish being most efficient. But what it would be good for is getting rid of the damn exhaust drone cruising @ 70MPH...

You also shouldn't be building any boost just cruising, it should be pretty much a N/A cruising at highway speeds on our light little cars...

 

[Diamond Star Werks]

EVO gear line FTW! shep stage 4 also FTW. 2650rpm at 65 i believe, havnt driven her enough since the rebuild to remember exactly. Haha

I do that with my stock trans on 235/45/17s. I hit 70mph about 2900. 3000 is 73. 80 is about 3400. 90 is about 3900. Autos will be higher due to torque converter slippage. And no there are no dsms that came with lock-up converters.

 

[Wild93GS]

Edit.
26-2700 at 60 today on 225/45r18's. 95 awd.
Could the difference in getting in the t cases and transmissions make a difference? I don't understand gearing too well so someone correct me if I have my thinking wrong.

 

[GSX95AWD]

Well the rear tires are 245/55/ZR17. And the fronts are 225/45/ZR17. Could the tire size be affecting performance and speed? I know stock is 205/55/16 all the way around. could the fatter tire be the cause ?

 

[TSIflyer95]

Well the rear tires are 245/55/ZR17. And the fronts are 225/45/ZR17. Could the tire size be affecting performance and speed? I know stock is 205/55/16 all the way around. could the fatter tire be the cause ?

Width will not effect it. Height will though. With a larger wheel/tire combination your wheels are turning slower. With a smaller wheel/tire combination, your wheels turn fast. This can have an effect on your speedometer. But nothing too serious. You need not to worry. Your rpms are within the normal range. Speedo may be reading a little slow. But 3k at 60mph is common. My talon was like that, and my buddies gsx is like that.

 

[andrew k]

Well the rear tires are 245/55/ZR17. And the fronts are 225/45/ZR17. Could the tire size be affecting performance and speed? I know stock is 205/55/16 all the way around. could the fatter tire be the cause ?

running 2 different tire sizes on an awd is going to put a lotta extra stress on your drivetrain. those vicous couplings are probably hating life right now.

Well the rear tires are 245/55/ZR17. And the fronts are 225/45/ZR17. Could the tire size be affecting performance and speed? I know stock is 205/55/16 all the way around. could the fatter tire be the cause ?

your rear tires are 245mm wide 55 percent of 245 is 134.75mm divided by 25.4 so equals 5.3 inches tire radius so 17 plus 10.6 is 27.6
your rears are 27.6 inches tall approx.
101.25 divided by 25.4 is 3.98 times 2 equals 7.96 plus 17 approx 25 inches

your rears are approx 27.5 in tall
your fronts are approx 25 in tall
2.5 in from front to rear difference thats quite a lot

 

[GSX95AWD]

running 2 different tire sizes on an awd is going to put a lotta extra stress on your drivetrain. those vicous couplings are probably hating life right now.



your rear tires are 245mm wide 55 percent of 245 is 134.75mm divided by 25.4 so equals 5.3 inches tire radius so 17 plus 10.6 is 27.6
your rears are 27.6 inches tall approx.
101.25 divided by 25.4 is 3.98 times 2 equals 7.96 plus 17 approx 25 inches

your rears are approx 27.5 in tall
your fronts are approx 25 in tall
2.5 in from front to rear difference thats quite a lot

For 17" rims, what size tire would be best all the way around for my gsx?

 

[TSIflyer95]

Doesn't really matter. As long as they are the same. Easy way to put it. 225/35/17 all four. For example. Not 245/35/17 rear and 225/35/17 front. Just make them the same. It's less strain on the driveline. In some awd cars if you do that you screw up the entire driveline which becomes extremely costly.

 

[Diamond Star Werks]

Doesn't really matter. As long as they are the same. Easy way to put it. 225/35/17 all four. For example. Not 245/35/17 rear and 225/35/17 front. Just make them the same. It's less strain on the driveline. In some awd cars if you do that you screw up the entire driveline which becomes extremely costly.

He is right man. I was gonna say it but he beat me. On fwd it doesn't matter but for awd tire size needs to be the same. Im running 235/45 on 17/7 right now. You should be able to do the same depending in your offset.