Yes.

 

Technically yes. But in real life our car is drag limited at 160 or so. (Assuming the technosquare flash to remove speed limiter) Which makes all gearing beyond that pointless anyway without lots more power.

Cruising in 6th gear at 65 puts the tach at around 3000rpms.

 

omg! i thought that having the 3.9fd gearing would drop your top speed in 6th down around 140 or so... i couldn't live with that as i <HYPOTHETICAL SITUATION> love cruising around empty interstate roads at 155 </HYPOTHETICAL SITUATION>. but if there's no major loss at the top end, i think i'm going to go buy me some 3.9fd gears right now

 

Here are the approximate values. Theoretical top speed is reduced to 167mph. Which we can't hit anyway without a reflash and more power. With reflash top speed is 176. Also, you will not have to shift into 5th at the 1/4 mile. I wind 4th out and cross the second trap beam at around 6500 rpms. If I were going to improve 1/4 times with this setup, I would add a plenum and headers. That would help generate more power near redline.

3.538 OEM vs. 3.917 350EVO
Gear/ max speed OEM / max speed 4.0 @ 6850 RPMS
1st/ 38.9 / 35.1
2nd/ 63.5 / 57.3
3rd/ 90.8 / 82.0
4th/ 116.1 / 104.8
5th/ 147.1 / 132.9
6th/ 185.6 / 167.6


With Technosquare reflash
1st 36.9
2nd 60.3
3rd 86.2
4th 110.2
5th 139.7
6th 176.5

 

Great info zillinois, we really appreciate it. I just ordered the tilton clutch/flywheel combo and will be ordering the nismo lsd and 3.9fd at the beginning of the year, I was just curious how much the gears would cut down the top speed.. I doubt I'll ever hit 150 let alone 167.

 

Great write up.
Just curious how did you get a clutch replacement under warranty??

 

 

Here is the secret to getting your wear items replaced for free. Blow them up real good, don't just wear them out.


BTW, I'm going to the dyno tonight. I should have some numbers later.

 

I run a similar setup, 3.9 final drive and Tilton "rally" semi-street clutch/flywheel. I love this and can't recommend it enough!

I have about 5,000 miles on the clutch and it is holding up good to my daily street driving as well as a couple track days and about 10 drift days. The clutch is agressive for daily driving, but it is usable.

Running some shorter than stock rear tires (245/40/18) My car tops out at speedo indicated 150mph (redline stock ECU 6'th gear) and can bounce off the limiter still pulling.

 

Here are the dyno graphs. Thanks to Charles @ CJMotorsports. This dyno includes over prior run

Tilton
3.9 FD
Labree Pipes

Horsepower Peak 262.05 w/ smooting set at 5. I had a pull at 265 but the graph was a bit jumpy so I took the next highest one.
From 75-115mph there is a 35hp increase!! You can see that the curve is pinched up earlier. This was my prediction that the area under the curve would be about the same it would just be peakier.


Torque Peak 254.The torque is especially peaky. From 50-95mph I've increased torque by 25ft/lbs!! You can really feel the power flatten out after 100. I think headers and plenum would really help this setup breathe at the high end.

 

Looking good! what gear did you end up dynoing in? Do you happen to have the plots of HP vs. RPM or Torque vs. RPM?

I agree that some headers, manifold, and cams will complete your N/A package, that is the route I am planning on going.