I've got the T5 out of my friends 88 GTA with the 3.45 9bolt.

On the highway with 3.73 gears in 5th at around 70-80mph I am taching about 3K.

I thought I had a .72 OD, but I was reading a site and they mentioned a .85 OD.

 

Most T5s came with .63 overdrives. A very few got a shorter overdrive but those were mostly later 1LE cars. Mine has the .63 overdrive and with 3.42 gears my turns 2500 at 70mph.

 

all non 1LE cars got the .63..the 1LE's got the .73.....there wernt anyother overdrives but those 2...

with the 3.42's and .63 overdrive
1,500 at 45 mph
2,000 at 60 mph
2,500 at 70 mph
2,800 at 78 mph
3,200 at 90 mph

 

Axoid--nice SOLO II foto...does the steering brace make much difference? Did you choose 3.42's over 3.23's for SOLO?

 

hey Axoid i was wondering where you got your rims from if you had them made or there just gta rims thanks

 

Thanks,
I didn't did notice a difference with the steering brace, but is was one of the first mods that I did and at the time I was still newbe and running 16x8 wheels. I'm now running 17x9.5s and I sure there is more stress going though the steering now than before. Plus the car was very solid when I bought it, so it may of not needed it then.

Yes, the car came with 3.08 gears and the 3.42s were the largest legal ratio. I occasionally get into the 6000 rpm range in second but not often.

The wheels are 17x9.5 3 piece CCW track wheels. www.ccwheel.com

 

L69 cars got the .73 gear too.

 

Thanks Axoid--not much SOLO II activity in West Texas--rats. My car's very solid, too, and I want to keep it that way--maybe see you in Topeka next year.

 

There's a lot of SOLO II here in the mid-west. I may go to Topeka next year, depends on how things go in the first half of the year. I am going to run some CenDiv events (Divisional Championship series) next year.

 

Excellent--I want to set up my '82 for E street prepared, too, and I haven't sent off for the SCCA rule book. I currently have 3.73's and was gonna change to 3.23's because of the distances out here, plus when I get to the mountains in New Mexico the 3.73's are just too deep for my stock 305.
If you were going to run on the street, lots of highways, and the mountains and E street prepared now and then, would you run 3.42's or 3.23's? Would 3.23's make my car non-competitive? I don't have to win every time but I wouldn't want to handicap my car--thanks.

 

I don’t think 3.23s will hurt you much if at all, specially if you have plenty of long runs.
My car isn't a dedicated autocross car; it sees its share of street and highway driving.

 

I have a 1990 camaro with a t5 and 3.45 and at 2000 i hit 80.

 

you dont have 3.45's..you have 3.08 gears if you hit 80@2000
its actually 79.75mph or 2006 rpm

 

My stock 1983 T-5, behind the LG-4, came with the .73 overdrive.

My car was also a WS-6 car with the 3:73 limited-slip diff.

 

Got a build sheet? I'd like to see a factory LG4 / 3.73 car.

 

My car has a 3.45 9 bolt rear end that came of a 1987 firebird. I now what my car has. It does 80 at 2000.

 

A mystery no longer:lala:

 

If you had a gear ratio numerically lower than 3.45 and didn't recalibrate your speedo gears, then your speedo is reading high.

 

My speedo is perfect. I got a radar gun and did it. And also did it on the high way with my buddy. He also told me that i was doing 80. Beleive me that it is right.

 

Axoid--thanks--I'm going with 3.23's then--got to get that rule book.

 

there are 2 things that are possible here..
1. your car has 3.08's
2. you tranny has a .56 5th gear
3. your speedo isnt calibrated for the 3.45 gears

there wasnt ANY .56 5th gear....

now do us all a favor and go the the EQUATIONS section on the main page...

under the MPH equation put in 13 for tire radius, 2000 for engine RPM, 3.45 for rear end ratio and .56 for tranny ratio...that equals 80 MPH...once again THERE WASNT ANY .56 5TH GEAR

now put in 3.08 for the rear end ratio (since that what LO3 cars got) and .63 for the tranny ratio (since that was LO3 cars got) that equals 80 MPH....

and just for your information the 9 bolt wasnt available in 87 firebirds...only 88-89 GTA'S

 

This reminds me of my '58 BelAir in 1966 with the 348 and three 2's--I knew what I had.