rear gear

[gnx107]

hi all , like to change rear gear but race 1/8 and 1/4 mile and street drive some . have a 342 now . so how low to go ? car only runs 8.0 in the 1/8 mile . thanks for any help gnx107[/list]

 

[Blake442]

Welcome!

3.42's are actually an excellent compromise for street and track duty.
If you have an overdrive trans (200-4R), 3.73's would be a good upgrade, or maybe even 4.10's.
If you're only running a three speed, I'd leave the gears alone personally. That way you don't have to rev the thing so high on the freeway like I do. :lol:

 

[gnx107]

Welcome!

3.42's are actually an excellent compromise for street and track duty.
If you have an overdrive trans (200-4R), 3.73's would be a good upgrade, or maybe even 4.10's.
If you're only running a three speed, I'd leave the gears alone personally. That way you don't have to rev the thing so high on the freeway like I do. :lol:[/quote ] thanks and yes i have overdrive so i was thinking 3.73 thanks gnx107

 

[87National]

Just curious.......from looking at you screen name it appears you may have a GNX. Is this the car that you are referring to in your post?

hi all , like to change rear gear but race 1/8 and 1/4 mile and street drive some . have a 342 now . so how low to go ? car only runs 8.0 in the 1/8 mile . thanks for any help gnx107[/list]

 

[gnx107]

Just curious.......from looking at you screen name it appears you may have a GNX. Is this the car that you are referring to in your post?
yes I one gnx and 2 87 grand national . just trying to do a little to the gnx its fun to go play somtimes .

hi all , like to change rear gear but race 1/8 and 1/4 mile and street drive some . have a 342 now . so how low to go ? car only runs 8.0 in the 1/8 mile . thanks for any help gnx107[/list]

 

[87National]

The 3.8 will tend to run out of breath above 5000 rpm, which is where a stock or near stock gn will be at the end of the 1/4 mile (assuming 26" tall tires and stock 3.42 rear). If this was going to be an 1/8 mile car exclusively, then I could see some benefit to 3.73 or 4.11 gears. However, most of the 10 and 11 second turbo buicks still run stock 3.42 gears. If you are looking to go faster, you may want to consider a higher stall torque converter, bigger turbo, 3" downpipe/exhaust, or alcohol injection.

 

[gnx107]

The 3.8 will tend to run out of breath above 5000 rpm, which is where a stock or near gn will be at the end of the 1/4 mile (assuming 26" tall tires and stock 3.42 rear). If this was going to be an 1/8 mile car exclusively, then I could see some benefit to 3.73 or 4.11 gears. However, most of the 10 and 11 second turbo buicks still run stock 3.42 gears. If you are looking to go faster, you may want to consider a higher stall torque converter, bigger turbo, 3" downpipe/exhaust, or alcohol injection.

thanks alot that was real good information . . . . makes me think i need a higher stall torque converter . I have a 3 downpipe and t 49 turbo 42 lb injectors race shocks and springs but stock torque converter . . race last friday 1/8 mile, ran only a 8.1 and 8.2 all night . I would like run 7.85 then i will be happy now my 87 grand national we are all most done . built the heck out of it hoping it will run hi 6 thanks gnx107

 

[dogsht]

Here are some sites that will have great information for you to get a lot more out of what you already have safely. These cars are first & foremost about tuneing. Without a scan tool of some type you are flying blind. Often just trying to apply old school hot rod tricks doesn't work well for these cars. The gearing, original basic suspension shocks springs etc won't hold these up until you are in the 10s in my experience.

www.gnttype.org
www.turbobuicks.com
www.turbobuick.com

ps you really won't benefit much from more gear and with a ta49 you won't benefit a lot from a converter yet. You need to get the boost, fuel, & timeing, right to "let the animal out" so to speak. You can follow some of the basic "recepies" to get way more power without hurting her.

 

[87National]

The 3.8 will tend to run out of breath above 5000 rpm, which is where a stock or near gn will be at the end of the 1/4 mile (assuming 26" tall tires and stock 3.42 rear). If this was going to be an 1/8 mile car exclusively, then I could see some benefit to 3.73 or 4.11 gears. However, most of the 10 and 11 second turbo buicks still run stock 3.42 gears. If you are looking to go faster, you may want to consider a higher stall torque converter, bigger turbo, 3" downpipe/exhaust, or alcohol injection.

thanks alot that was real good information . . . . makes me think i need a higher stall torque converter . I have a 3 downpipe and t 49 turbo 42 lb injectors race shocks and springs but stock torque converter . . race last friday 1/8 mile, ran only a 8.1 and 8.2 all night . I would like run 7.85 then i will be happy now my 87 grand national we are all most done . built the heck out of it hoping it will run hi 6 thanks gnx107

Have you considered alcohol injection? Adding alcohol injection, I went from running 14 lbs of boost to 22 lbs. The difference was night and day.

 

[gnx107]

Here are some sites that will have great information for you to get a lot more out of what you already have safely. These cars are first & foremost about tuneing. Without a scan tool of some type you are flying blind. Often just trying to apply old school hot rod tricks doesn't work well for these cars. The gearing, original basic suspension shocks springs etc won't hold these up until you are in the 10s in my experience.

www.gnttype.org
www.turbobuicks.com
www.turbobuick.com

ps you really won't benefit much from more gear and with a ta49 you won't benefit a lot from a converter yet. You need to get the boost, fuel, & timeing, right to "let the animal out" so to speak. You can follow some of the basic "recepies" to get way more power without hurting her.

thanks you have been helpfull . just got a scan tool now if i just use it wright. being green on this sucks but it s all good . gnx107