New gears for the C4. Anybody else done this?
11-16-2018, 10:38 AM
#1
Instructor
Thread Starter
New gears for the C4. Anybody else done this?
so I know this has come up in the past, people asking "what gear ratio is best"
just hear me out, because all the threads I've read through on the topic, people are using completely stock cars
I'm wondering if since there are a few mods to the car, if I should be looking at a different ratio
car is a 96. 4l60E. D36 with the stock 2.59 ratio rear end
at the wheels, it dynoed at 392 HP and 350 TQ.
stock LT1 bottom end. Ported Edelbrock LT4 Performer RPM heads and manifold, Cam, Long tubes, etc. bumped up the compression a bit too. Pulls hard all the way to 6500 rpm
The car is a street car, occasional runs at willow. all new suspension and Bear 14.25" 6 piston calipers all the way around
so. I see a lot of people saying the 3.54 is the way to go, but these are all on stock cars trying to pep them up a bit. should I be looking at a different ratio than this? has anybody had any experience in this area with these cars? I don't care if I need to swap to a new carrier. Just need to figure this out before I get my new TC ordered from ATI.
Thanks for any input
just hear me out, because all the threads I've read through on the topic, people are using completely stock cars
I'm wondering if since there are a few mods to the car, if I should be looking at a different ratio
car is a 96. 4l60E. D36 with the stock 2.59 ratio rear end
at the wheels, it dynoed at 392 HP and 350 TQ.
stock LT1 bottom end. Ported Edelbrock LT4 Performer RPM heads and manifold, Cam, Long tubes, etc. bumped up the compression a bit too. Pulls hard all the way to 6500 rpm
The car is a street car, occasional runs at willow. all new suspension and Bear 14.25" 6 piston calipers all the way around
so. I see a lot of people saying the 3.54 is the way to go, but these are all on stock cars trying to pep them up a bit. should I be looking at a different ratio than this? has anybody had any experience in this area with these cars? I don't care if I need to swap to a new carrier. Just need to figure this out before I get my new TC ordered from ATI.
Thanks for any input
11-16-2018, 10:43 AM
#2
Safety Car
so I know this has come up in the past, people asking "what gear ratio is best"
just hear me out, because all the threads I've read through on the topic, people are using completely stock cars
I'm wondering if since there are a few mods to the car, if I should be looking at a different ratio
car is a 96. 4l60E. D36 with the stock 2.59 ratio rear end
at the wheels, it dynoed at 392 HP and 350 TQ.
stock LT1 bottom end. Ported Edelbrock LT4 Performer RPM heads and manifold, Cam, Long tubes, etc. bumped up the compression a bit too. Pulls hard all the way to 6500 rpm
The car is a street car, occasional runs at willow. all new suspension and Bear 14.25" 6 piston calipers all the way around
so. I see a lot of people saying the 3.54 is the way to go, but these are all on stock cars trying to pep them up a bit. should I be looking at a different ratio than this? has anybody had any experience in this area with these cars? I don't care if I need to swap to a new carrier. Just need to figure this out before I get my new TC ordered from ATI.
Thanks for any input
just hear me out, because all the threads I've read through on the topic, people are using completely stock cars
I'm wondering if since there are a few mods to the car, if I should be looking at a different ratio
car is a 96. 4l60E. D36 with the stock 2.59 ratio rear end
at the wheels, it dynoed at 392 HP and 350 TQ.
stock LT1 bottom end. Ported Edelbrock LT4 Performer RPM heads and manifold, Cam, Long tubes, etc. bumped up the compression a bit too. Pulls hard all the way to 6500 rpm
The car is a street car, occasional runs at willow. all new suspension and Bear 14.25" 6 piston calipers all the way around
so. I see a lot of people saying the 3.54 is the way to go, but these are all on stock cars trying to pep them up a bit. should I be looking at a different ratio than this? has anybody had any experience in this area with these cars? I don't care if I need to swap to a new carrier. Just need to figure this out before I get my new TC ordered from ATI.
Thanks for any input
So what are you planning on doing with the car?
-- Joe
11-16-2018, 11:01 AM
#3
Team Owner
Member Since: Sep 2001
Location: Athens AL
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Totally depends on what you want to do and what your powerband looks like.
The reason that the gear change is suggested is because the LT1/4 make their power at higher RPM due to the short runners on the intake, and a gear swap gets you into that band quicker, making the car faster to 60 but possibly cutting your top speed (that you don't ever get to see off a track anyway). Torque converter changes are doing the same thing. Stock TC for you is about 1600rpm, too low.
L98s don't need the gear change because the intake setup causes the powerband to all be in the low/mid RPM range.
The reason that the gear change is suggested is because the LT1/4 make their power at higher RPM due to the short runners on the intake, and a gear swap gets you into that band quicker, making the car faster to 60 but possibly cutting your top speed (that you don't ever get to see off a track anyway). Torque converter changes are doing the same thing. Stock TC for you is about 1600rpm, too low.
L98s don't need the gear change because the intake setup causes the powerband to all be in the low/mid RPM range.
11-16-2018, 01:48 PM
#4
With that much HP/TQ you might want to do a D44 anyway. It isn't that hard to find a factory D44 with 3.45 gears from a manual car and the swap is pretty straight forward. Complete rearends exist that came with the 3.54 but they are pretty hard to come by. I went from 3.07s to 3.45s in my 93 with a 4L60 and it really woke the car up. Going from 2.59s to 3.45s will feel like you gained a 100 horses.
Last edited by Wharf Rat; 11-17-2018 at 08:48 PM.
11-16-2018, 03:45 PM
#5
Race Director
If you are buzzing to 6500, get a 3.73. I went with that ratio when my car was a street/strip car with a 4l60e and it worked well.
11-16-2018, 05:07 PM
#6
Race Director
I got a supercharged 93 with m6.
ive pondered this for years.
what do i gain, what do i lose?
if i cant get any traction in first anymore, do i gain anything ?
currently, with the centrifugal blower, i get manageable traction in first on 315/35r17 proxes r888.
id hate for first to become unuseable.
and i believe first in the auto is a way higher numerical ratio vs first in the zf6.
So does first become unuseable ?
ive pondered this for years.
what do i gain, what do i lose?
if i cant get any traction in first anymore, do i gain anything ?
currently, with the centrifugal blower, i get manageable traction in first on 315/35r17 proxes r888.
id hate for first to become unuseable.
and i believe first in the auto is a way higher numerical ratio vs first in the zf6.
So does first become unuseable ?
11-16-2018, 07:15 PM
#7
Race Director
I got a supercharged 93 with m6.
ive pondered this for years.
what do i gain, what do i lose?
if i cant get any traction in first anymore, do i gain anything ?
currently, with the centrifugal blower, i get manageable traction in first on 315/35r17 proxes r888.
id hate for first to become unuseable.
and i believe first in the auto is a way higher numerical ratio vs first in the zf6.
So does first become unuseable ?
ive pondered this for years.
what do i gain, what do i lose?
if i cant get any traction in first anymore, do i gain anything ?
currently, with the centrifugal blower, i get manageable traction in first on 315/35r17 proxes r888.
id hate for first to become unuseable.
and i believe first in the auto is a way higher numerical ratio vs first in the zf6.
So does first become unuseable ?
11-17-2018, 07:30 AM
#8
Well,
If you choose to keep the Dana 36 and decide to put in a set of gears, I have a set of 3.07:1 or 3.08:1 ring and pinion for a Dana 36 that came out of my 85 I sold. They are in great shape with about 60,000 miles. I have them in the FS section and will sell them cheap plus shipping if interested.
Take care!
If you choose to keep the Dana 36 and decide to put in a set of gears, I have a set of 3.07:1 or 3.08:1 ring and pinion for a Dana 36 that came out of my 85 I sold. They are in great shape with about 60,000 miles. I have them in the FS section and will sell them cheap plus shipping if interested.
Take care!
11-17-2018, 07:25 PM
#9
Le Mans Master
….. The most cost effective solution and long term durability would be to pick up a D44 with 3.45 gears … they are the most plentiful and therefore most affordable replacement for your D36 … you'll be glad you did ! ….. you can buy a ring & pinion for your D36 and if you have it professionally installed you will have spent about what it would cost to buy the 44 … but you still have a D36 …..
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DykstraMotorsports (11-21-2018)
11-19-2018, 08:59 AM
#10
Drifting
so I know this has come up in the past, people asking "what gear ratio is best"
just hear me out, because all the threads I've read through on the topic, people are using completely stock cars
I'm wondering if since there are a few mods to the car, if I should be looking at a different ratio
car is a 96. 4l60E. D36 with the stock 2.59 ratio rear end
at the wheels, it dynoed at 392 HP and 350 TQ.
stock LT1 bottom end. Ported Edelbrock LT4 Performer RPM heads and manifold, Cam, Long tubes, etc. bumped up the compression a bit too. Pulls hard all the way to 6500 rpm
The car is a street car, occasional runs at willow. all new suspension and Bear 14.25" 6 piston calipers all the way around
so. I see a lot of people saying the 3.54 is the way to go, but these are all on stock cars trying to pep them up a bit. should I be looking at a different ratio than this? has anybody had any experience in this area with these cars? I don't care if I need to swap to a new carrier. Just need to figure this out before I get my new TC ordered from ATI.
Thanks for any input
just hear me out, because all the threads I've read through on the topic, people are using completely stock cars
I'm wondering if since there are a few mods to the car, if I should be looking at a different ratio
car is a 96. 4l60E. D36 with the stock 2.59 ratio rear end
at the wheels, it dynoed at 392 HP and 350 TQ.
stock LT1 bottom end. Ported Edelbrock LT4 Performer RPM heads and manifold, Cam, Long tubes, etc. bumped up the compression a bit too. Pulls hard all the way to 6500 rpm
The car is a street car, occasional runs at willow. all new suspension and Bear 14.25" 6 piston calipers all the way around
so. I see a lot of people saying the 3.54 is the way to go, but these are all on stock cars trying to pep them up a bit. should I be looking at a different ratio than this? has anybody had any experience in this area with these cars? I don't care if I need to swap to a new carrier. Just need to figure this out before I get my new TC ordered from ATI.
Thanks for any input
What is gained, mechanical advantage. At any given RPM, whatever torque you are producing is multiplied more by the gearing.
What is lost, top speed you never use and some MPG. Depending on your drive. I went to 4.10's in a Mustang from 3.55's and my average MPG went up due to my daily commute. It allowed me to drive in 5th between 45-55mph where the 3.55's didn't. However, on long highway trips it was less. Also, traction is lost. I had a Viper with 3.55's and traction was an issue with all that torque, and my SC LT4 has traction issues with the 3.45's. Both made about 380-390hp to the rear wheels, the Viper making more torque down low.
So when it comes to what gear is right, you have to decide what you want to intended purpose to be. Street performance where 30mph-90mph will be king, track where a full 1/8th or full 1/4 are king. a Touring car where economy comes into play?
What runs best in the 1/4 mile won't necessarily give you the best 30-90mph performance. I have an IROC with a TPI and 3.70 gears and love it. I don't track it, but from 30-90 getting on an on ramp or passing someone on a back road, it's the perfect gear. However, in a 1/4" mile car I know it would be slower due to traction issues and short RPMs..
If you want to do all 3, some compromises will need to be made. One could be to go to a 3.73 and put slicks on DOT Drag Radials on when you go to the track. The other could be to just sit down and figure what gear you want to cross the traps in, what MPH that will be, back into RPM and what ratio matches to produce that result.
However, I agree with the other posters, I would first start with a D44 3.45 rear end, swap it in, and see if you like it or want to go lower. I would personally suggest based of the information you gave, the 3.45 will be the best overall for your application. I will say this, I have rarely seen anyone upset they went with a lower (higher numerically gear) when they were on the fence between two ratios, and have seen plenty wish they would have bit the bullet and went lower. Unless they did something extreme like a 2.73 to a 4.56.
Last edited by KyleF; 11-19-2018 at 04:38 PM.
11-19-2018, 09:23 AM
#11
Instructor
Thread Starter
Sorry for the late response. was out of town
anyways, the car is a street car that is used for road race. doesn't ever really see a strip
some back story on why we are doing this. basically, whatever TC in in there now is either too high of a stall, or is not locking up right. I can be driving it on the freeway in overdrive and you can feel it locking and unlocking as you go. this is creating crazy heat in the trans when its not even being used hard.
I have intention of changing this out to a TCI, but have always wanted to swap the gears in the car (definitely been wanting the D44, just haven't been able to come across one yet) so I figured I would get the gears I want then the TC so they match. no point in spending all that money just to make a change that will throw it off
I'm not worried about the price of install. I'd be doing it in house. About how much does a D44 rear set up go for? and does anybody know of one for sale?
I'll find the dyno sheet and put it up when I get a chance so we can take a look at where the power comes in at
anyways, the car is a street car that is used for road race. doesn't ever really see a strip
some back story on why we are doing this. basically, whatever TC in in there now is either too high of a stall, or is not locking up right. I can be driving it on the freeway in overdrive and you can feel it locking and unlocking as you go. this is creating crazy heat in the trans when its not even being used hard.
I have intention of changing this out to a TCI, but have always wanted to swap the gears in the car (definitely been wanting the D44, just haven't been able to come across one yet) so I figured I would get the gears I want then the TC so they match. no point in spending all that money just to make a change that will throw it off
I'm not worried about the price of install. I'd be doing it in house. About how much does a D44 rear set up go for? and does anybody know of one for sale?
I'll find the dyno sheet and put it up when I get a chance so we can take a look at where the power comes in at
11-19-2018, 10:02 AM
#12
Safety Car
Sorry for the late response. was out of town
anyways, the car is a street car that is used for road race. doesn't ever really see a strip
some back story on why we are doing this. basically, whatever TC in in there now is either too high of a stall, or is not locking up right. I can be driving it on the freeway in overdrive and you can feel it locking and unlocking as you go. this is creating crazy heat in the trans when its not even being used hard.
I have intention of changing this out to a TCI, but have always wanted to swap the gears in the car (definitely been wanting the D44, just haven't been able to come across one yet) so I figured I would get the gears I want then the TC so they match. no point in spending all that money just to make a change that will throw it off
I'm not worried about the price of install. I'd be doing it in house. About how much does a D44 rear set up go for? and does anybody know of one for sale?
I'll find the dyno sheet and put it up when I get a chance so we can take a look at where the power comes in at
anyways, the car is a street car that is used for road race. doesn't ever really see a strip
some back story on why we are doing this. basically, whatever TC in in there now is either too high of a stall, or is not locking up right. I can be driving it on the freeway in overdrive and you can feel it locking and unlocking as you go. this is creating crazy heat in the trans when its not even being used hard.
I have intention of changing this out to a TCI, but have always wanted to swap the gears in the car (definitely been wanting the D44, just haven't been able to come across one yet) so I figured I would get the gears I want then the TC so they match. no point in spending all that money just to make a change that will throw it off
I'm not worried about the price of install. I'd be doing it in house. About how much does a D44 rear set up go for? and does anybody know of one for sale?
I'll find the dyno sheet and put it up when I get a chance so we can take a look at where the power comes in at
-- Joe
11-19-2018, 10:32 AM
#13
Racer
I have a (basically stock) 96 A4 and did the 3.54's.
The biggest issue is finding someone to calibrate the speedo and possibly move the shift points.
Either buy the Jet DST yourself (400.00, plus older laptop to run it) or make sure you know someone who can do it. The only tuner around Sac who could do it closed down before i got it done.
Love the spunky gearing but it shifts really fast under normal acceleration and my speedo is about 20mph+/- off.
The biggest issue is finding someone to calibrate the speedo and possibly move the shift points.
Either buy the Jet DST yourself (400.00, plus older laptop to run it) or make sure you know someone who can do it. The only tuner around Sac who could do it closed down before i got it done.
Love the spunky gearing but it shifts really fast under normal acceleration and my speedo is about 20mph+/- off.
11-20-2018, 12:55 AM
#14
Check Craigslist and the local junk yards. Fair market price for a D44 is roughly 700-1200 depending on the mileage, condition, and what gear it has.
You can reuse your c-beam and driveshaft and make it work or for about $200 you can get the right c beam and driveshaft.
You can reuse your c-beam and driveshaft and make it work or for about $200 you can get the right c beam and driveshaft.
11-20-2018, 10:14 PM
#15
Instructor
Thread Starter
and what year out of?
so I think its a slipping TC. been doing some research. the computers will unlock the converter if they sense slip. at 55 that thing should be fully locked. if it senses a different rpm at the motor, vs speed at the trans, it will unlock the converter. the tuning worked great and now its starting to slip and unlock, so I think I'm having an issue with that
gunna search for a D44 with 3.45s, should be a nice bump from the 2.59s in it right now, then have my tc rebuilt.
so I think its a slipping TC. been doing some research. the computers will unlock the converter if they sense slip. at 55 that thing should be fully locked. if it senses a different rpm at the motor, vs speed at the trans, it will unlock the converter. the tuning worked great and now its starting to slip and unlock, so I think I'm having an issue with that
gunna search for a D44 with 3.45s, should be a nice bump from the 2.59s in it right now, then have my tc rebuilt.
11-20-2018, 10:26 PM
#16
Instructor
Thread Starter
just purchased a D44 out of an 87 with 3.07s in it.
gotta get some gears now. 3.45 should be all around best? or what? because I've gotta buy some
also, does anybody know what the ratio split for the carrier is? can I use the same carrier?
gotta get some gears now. 3.45 should be all around best? or what? because I've gotta buy some
also, does anybody know what the ratio split for the carrier is? can I use the same carrier?
11-21-2018, 01:46 AM
#17
I have the 3.45 because that is what is most readily available in a D44. If I could pick I'd go with a 3.73. The 3.45 is a huge step up from the 3.07 but I'd still like a little more. 3.07 is nowhere near enough on an LT1.
11-21-2018, 08:29 AM
#19
Drifting
This. The TPI cars love the 3.40ish range when mated with the 700R4. The LT1 pulls higher in the RPM range. A3.45 would be very nice. I think you will like a 3.73 better, if you were a 6-speed I would be hard selling you on a 4.10. DON"T FEAR THE GEAR!
