Hani

Hi Guys,

After my thread earlier this year: http://forums.bradbarnett.net/showthread.php?t=464868

I got 2008 Mustang back in July and it came with the standard 3.31 rear gear but I was not angry, at lease I got a manual transmission one which is found to be rare over here..

Till now, I had raced 2 Mustangs, both are 2007 with automatics transmission.

Here is a video for the 1st race: http://www.youtube.com/watch?v=aKIpm8_r5Iw (my car is on the right), his Mustang is convertable and he says that it has only a cat-back exhaust (I don't know the brand), he says that he is the winner!!!

On this specific race, we started from 40 km/h (25 mph) and I was in 1st gear.. he pushed the 3rd horn and kicked it and I kicked it after him.. we stayed on the same line all 1st and 2nd but by the end of the 2nd, I was starting to take the head and when changed to 3rd we had the road twisting and becoming dangerous to continue so he braked..

For information, we had an earlier trial and I gave him 1.5 cars difference in 3rd gear but he execused that his transmission got delayed in changing from 2nd to 3rd.. he had the video for this race and did not post it!!!

Today, just now, I tried with a stock 2007 Mustang with automatic transmission from the same speed and It was completely different.. I had the lead from the begining of the race and gave him almost 2 cars length upto the end of 3rd gear!!! I was really happy and came to know that the guy I raced earlier had more modificiation on his car, more that a cat-back exhasut...

My questions, is it really possible for the convertable one to have only cat-back? I presume that he had other modifications but would not argue with him.. but I go angry when he posted the video on our local forum.. especially when it does not show that he won.. I want your opinion mates.. which car had the lead: the one on the right or the one on the left???

Second, I became mad for losing the privilege of having the 3.55 ratio axle with my manual transmission.. and intending to upgrade to the 3.55.. noting that I have no intensions to modify the car in the near future, I have the following questions:
1- Is it easy to upgrade from my factory 3.31 to the 3.55??? is it worthy???
2- Does it need any calibration, tuning,... to have correct reading on the speedometer after the 3.55 installation???
3- I am intending to have it done at our Ford delaer and I presume that installing the 3.55 at their shop will not void the car warranty.. is it right???
4- What is the part number for the 3.55 ratio axle from Ford??? what brand is it???

Sorry for my lengthy post.. but would really appreciate your input guys..

jasongt06

you are not going to see much gain going fro 3.31 to 3.55. In order to see a gain you usually have to go two sizes up in order to notice much of a gain. If it was mine I would put in 3.73 or 4.10.

Hani

I know that gain will not be that much..

I am intending to keep the car stock for few years.. so not looking for the 3.73 and 4.10 at this stage.

My idea is I want to get the 3.55 with my manual transmission (to recover the my mistake for not ordering the 3.55 gears when I ordered the car)..

I've done a search on the forum and the 3.55 gears seem to be the best choice by everybody for the manual transmission non-modified Mustangs

I found this link: http://www.buyfordracing.com/shop/pr...=642cPath=3_37 and I am not sure if this is a fair price

Also, nothing mentioned on the tune required to correct the speedometer..

If anyone knows the part number for the factory 3.55 gears used, please post it.. it will help me when going to our Ford delaer here

Thanks..

Indystang

Somebody do the math on the difference in RPM at 5750 rpm through the gears for him. It's hardly noticible I think.

metroplex

TR-3650 w/ 3.55s at 6000 RPM:
1st: 41
2nd: 68
3rd: 104

TR-3650 w/ 3.31s at 6000 RPM:
1st: 43
2nd: 73
3rd: 111

69Mach1-409

Questions:
1) fairly easy job, but you'll need a professional to do it right.
2) yes, you'll be roughly 5 mph off at 70
3) Depends on the shop. I believe if you had it done prior to taking delivery it would be 3yr/36k miles, but now it might not be covered at all.
4) I'm not sure what the OEMs are, but I know FRPP sells 3.55's for the 8.8.

I'm not sure you'll see much of a diff with the 3.55's. I understand you not wanting to void the warrenty, but it's probably going to cost a good chunk of change to get you maybe a tenth in the 1/4.

gmantheman

I would skip the 3.55 and 3.73 and get the 4.10s. Check with your dealer and see if they will warranty the gears, if not, have a performance/speed shop install the gears. Usually the dealer will charge more for the gear install. Don't worry too much about hwy driving and 4.10s. I drive over 60 miles per. day on the hwy and I have 4.10s. No complaints. I may have lost 1-2 MPG on the hwy, not sure though. I still avg. 24-25 MPG on the hwy driving 75-80 MPH.

metroplex

I would keep the 3.31s and drive 60-65 MPH on the highway (no faster).

randy_tho

Remember the bullit has 3.73 gears so that is sort of a factory option.

Hani

Yeah, Bullitt seems to have a nice launch but we don't have Bullitt Mustangs over here..

My idea was only to have the 3.55 with my manual transmission and be one of the fastest stock manual transmission GT Mustangs in here

From what I see, I think I will stick to the 3.31 as it seems not to be worthy to change to 3.55 I should have ordered it from the begining though..

Hani

Thanks for your reply on each point

Yes, I want to keep the warranty.. we have a strange Ford agent here that think if I do any minor modification to the car.. they will directly void my warranty even if it is from FRPP item and installed by them

metroplex

I suppose with your gas prices, the gas mileage issue isn't a big deal. However, I did order my GT with 3.55s and in retrospect I should have stuck with the stock 3.31s

I made the same mistake with my 2000 Crown Vic. I ordered it with the handling/performance package that included 3.55s, which causes the engine to run at 2500+ RPM at 80 MPH. I'd have to drive no faster than 55-60 MPH to get 21 miles per gallon, while the Crown Vics with 2.73s are enjoying 28+ MPG at 70 MPH.

Hani

Yeah.. we are enjoying gas price of 0.83 $ per gallon..

The issue is that I found the order guide of the 2008 GT Mustangs on this forum only after one day from ordering my car from the only Ford delaer here.. I told them to amend the order and add the 3.55 gear option but the guy told me it is better not to change any thing in the order as they hardly were able to place the order.. they were out of 2008 Mustang allocation with Ford.. but my order went through.. so I am lucky..

After my trial with the 2007 automatic Mustang.. I am quite happy that I ordered mine in manual.. I will try to forget the 3.55s hear issue

Thanks for the comments mates..

gmantheman

At .83 cents per. gal, get the 4.10s.

07GTTOM

if your going to pay the money, do it right the first time and go 3.73's or 4.10's, and a cai with a tuner.

H8IMPORTS

IMO I would go with a cold air intake, tune and 3.73's or 4.10's. I have a 08 GT with stock 3.31 gear ratio in it and I'm fixing to install 3.73's in mine. Only because there are free. If I was going to buy any it would be 3.90's or 4.10's. These cars need gears. Don't fear the gear. I hace a JLT, Bamatune and I love it. I raced a buddy of mines GTO that had air intake and full exhaust and when we ran 1st and 2nd we were dead even and when I shifted to 3rd he started to pull on me till I got my rpms up and then he didn't pull anymore. When we shut down I was still in 3rd and he was in 4th gear. If I would have had gear it would have been a lot better race. I would suggest getting some gears and don't look back.

Get gears, tune and CAI. I suggest JLT or C&L and a Bamatune.