I have a 1999 gsx eclipse, and i take it out on the highway alot. With that being said this car rund pretty high rpms while going 80 mph. So my question is how could i get like a 25% taller 5th gear for when im on the highway

Use 5th gear from a FWD GST

Are you SURE the FWD 5th gear will work in a AWD? We have always been looking for the EVO 5th gear but never heard of using a FWD 5th and hate to give out erroneous info.
@twicks69 , what do you say about this Tim?

Not sure what he is talking about as the ratio of 5th gear in FWD is 0.741 which is lower than the 0.666 in the AWD. It's the final drive on the FWD of 4.153 which makes the total ratio in 5th 3.077 which is taller than the AWD total ratio in 5th of 3.227. So even if it would fit the FWD 5th would make your RPM's higher on the freeway in an AWD which I'm sure is the opposite of what OP is looking for.

The only way to go taller in 5th is the Evo 3 5th which is 0.617 and makes your total ratio 0.299 on a 97-99 secondary and 3.042 on a 90-96 secondary

You NEED to run the FWD 5th gear needle bearing sleeve with the FWD 5th gearset, then clearance the bottom side of the 5th gear (detail gear and curve the teeth a little) otherwise use a rear diff pinion preload spacer to offset the gear a bit higher. The assembly height is different.

All is doable, but you need to know what you are doing and use the right parts to make it work.

WITH THAT SAID...... FWD 5th gearset (0.741 ratio) is 11% SHORTER than the AWD 5th gearset (0.666 ratio).

The Evo 1-3 5th gearset has been discontinued for years. You might find a used set pop up on places to purchase. This is a straight drop in gearset with no modifications when using a 1991.6-1999 AWD transmission.

Only way you are going with a taller 5th nowadays is a custom 5th gearset or running a PPG 5th gearset (0.633 ratio -- 5% taller than AWD DSM 5th) and modifying the transmission case to delete the reverse synchro, reverse wave spring, reverse cone and fasteners and the casting in the 5th gear cover (while keeping the input shaft oil guide) by grinding the cover smooth, then you will need to change the detent range and shape a bit to engage 5th and ramp the detent to keep pressure on the 5th engagement side so the slider doesn't rattle.

If you are planning on wasting like $1500, then this is for you.

If you choose to run a taller than PPG 5th gearset, then you will need to do more clearance modifications to the tops of the 1/2 and 3/4 shift rails to clear the larger diameter of the input 5th gear, and then modify the main case oil guide as it will contact the gear as well. If you contact MTM custom ratios on Facebook, their page is https://www.facebook.com/MTMCustomGearRatios

Thanks guys!!!!

When these cars were built it basically wasn't legal to go over 55! Now there are plenty of interstates around me where the posted limit is 80, so I kind of get what this guy is saying. But honestly I think the going faster part is worth the slightly higher revs part. Ideally a taller top gear would be great, but passing could be weird when you're going 75 and have to drop into 4th? Sounds like a lot of effort/ expense also.

They're geared low for a reason, the car makes better power at higher RPM. I actually get better mileage in my car at 85 than I do at 75 and the cruise isn't constantly trying to compensate for speed because it's lugged down more at 75 than 85. These arent small block V8's that can turn 1600 RPM at 80, low compression 2.0's don't make the torque at lower RPM to do it.

The cheapest way you can drop a couple of RPM's is to put a 26" or near tire on the car.

Haha yeah I've been wondering the same thing...but I have a FWD!! It sucks doing 80 down the freeways in LA, getting my doors blown off on both sides as other drivers race by in a hurry in their crappy Tesla's, BMWs and Benzs, and seeing my RPMs already at 3500! I'm thinking maybe some 19" wheels would help??

Sniffbooger said:

Haha yeah I've been wondering the same thing...but I have a FWD!! It sucks doing 80 down the freeways in LA, getting my doors blown off on both sides as other drivers race by in a hurry in their crappy Tesla's, BMWs and Benzs, and seeing my RPMs already at 3500! I'm thinking maybe some 19" wheels would help??

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Wheels wont change your gearing, rolling diameter will. What size tire do you have on the car right now? A taller tire will make your gearing longer so if you have something like a 225/45/17 a 225/50/17 would drop the RPM's SOME. Works the same way if you have 18's, just keep it 26" tall and under and you'll be OK pending wheel specs and how low you are.

Sniffbooger said:

Haha yeah I've been wondering the same thing...but I have a FWD!! It sucks doing 80 down the freeways in LA, getting my doors blown off on both sides as other drivers race by in a hurry in their crappy Tesla's, BMWs and Benzs, and seeing my RPMs already at 3500! I'm thinking maybe some 19" wheels would help??

Click to expand...

The extra rotational weight of the 19” wheels and tires would prolly negate any fuel savings from the few hundred rpm drop.