Regardless if you lose it or not it is still a good mod for autos.

 

has anyone clocked their speed changes? how much of a difference would it be? I'm thinking about just paying 450-500 to buy what i need from 350evo and then going and getting everything installed.

 

anyone have any numbers on the gains?

 

why would you loose cruise control with a gear change? so the car thinks it's going faster then it really is, how does this affect CC. is it a direct swap or is some sensor left unplugged with the new gears.

 

There are prox sensors on sprockets at the output shafts.
They provide the ECU with speed feedback.

If the speed doesn't match the expected feedback;
the cruise will kick out because it thinks there is a malfunction.

 

the speedometer does not change,it gets its info from the abs wheel sensors.they are on the stub axles,only tire size variances will change the speedo.my buddy is a md state cop and he verified my speed for me.

 

where can I pick up a set of gears for my 5AT. This sounds like it might be mod I will look into.

 

According to what I've read on this site and my350z.com, there is no 1/4 mile gain with gears. It "feels" faster thanks to the increase torque multiplication, but since the car has shift into 4th in the 1/4, the car falls on it's face. Last year I made two passes on 23" tall drag radials which effectively lowered my gear ratio to a 3.5. I had to shift to 4th about 300' short of the finish and the car was actually slower in the 1/4 mile compared to running the OEM 17" rims and 3.3 gearing that I had done 30 minutes earlier.

 

Interesting?? Then how did I beat a 05 G35 Coupe Auto much easier with the 3.5 gears then before with 3.3??

 

Out-reacting him? More mods on your car? Better launch? He's a crappy driver? Large rims on his car? Coupes are generally slower than the sedans. There are so many factors. If you really want to know, then take both cars to the track. That will tell you everything.

 

maybe they didnt go a whole quarter mile.

 

Coupes are not slower then sedans . I have an 03 Auto Coupe and he has a 05 Auto Coupe we are both on Stock 18's and we are modded just about the same. Their have been proven results of this swap to be beneficial for our cars. You are the first to say negative. When you put drag radials on a non FI G35 what do you expect??? DaveB you have a lot of good input that I have read in other posts but you are wrong on this one. Read my original post before posting. Your car shouldn't die in 4th?? We have the same gear ratio as MT coupes. Maybe your launch at the Drag strip wasn't good

 

DaveBs point may be entirely valid for the 1/4 mile.
Gearing is absolutely critical when maximizing performance for a specific distance.

The thing is ...the 1/4 mile mentality is singularly specific.
It does not equate to overall performance.

 

I was just about to say that. 1/4 mile times are affected because of the extra shift, but if you look at 60ft times or even 1/8 mile times, the time will be significantly better.

 

From the 1/4 mile times I've seen on the this, the coupes seem to be fractionally slower. That's all I'm saying.

Drag radials on my G35 were not for traction because my G35 has never had traction issues at the track. It pulls 2.1 60 foots all day with barely a chirp of the tires. The 225/50R15 DRs (17lbs lighter than the stock 17s too) were left over from my Maxima that I drag raced. I experimented with the DRs because they were 2.5" shorter than the 17s and I knew they'd dramatically increase torque multiplication (~3.52 gear) plus they were significantly lighter than the 17s.

During the day I raced, I was pulling higher 14.4s@97.5mph+ with higher 2.1 60 foots on the stock 17s. After a one hour cool down, I swapped on the 15" DRs and proceeded to pull lower 2.1 60 foots however the car could only muster lower 14.5s@96mph. With the DRs on, the car definitely felt more responsive. My 60 foots were fractionally better and my 330' was better. However, the slips clearly show the car wasn't accelerating as well at the 1,000 marker. Instead of being able to hold 3rd through the finish, the DRs forced a shift into 4th and you could definitely feel the acceleration being compromised by the tall 4th gear. To me, the slips show the proof that the "3.5" gearing isn't ideal if you care about the 1/4 mile.....which is what most of us are shooting for. To me, the fact that the car was doing 97.5mph traps on the 17s and then 96 traps on the DRs was proof enough to me that the 3.5 gear wasn't a good choice. I sold the DRs the following day.

Here are best of day slips on the 17s and then the DRs:

60' 2.191
330' 6.197
1/8 9.420@76.30
1,000 12.183
1/4 14.497@97.59


60' 2.141
330' 6.140
1/8 9.399@75.90
1,000 12.193
1/4 14.518@95.75


Think what you want about the 3.5 gear. To me, it's a waste for my intended goals. Deeper gearing isn't always the answer to improved performance. It is quite possible to overgear a car. Also, more torque multiplication will almost always give the sensation of stronger acceleration, but the 1/4 mile timers and trap boxes may disagree with your butt dyno. My buddies 90 LX 5.0 felt much quicker with 3.73s swapped in place of his 3.08 gears, but the reality was the car slowed down .1 seconds with the 3.73s because his stock 5.0 couldn't take advantage of the gearing.