What gear ratio for 1000hp 69 camaro?
 

I just got my 315/30/18 wheels mocked up and have got my width I need to get a custom ford 9" from Moser. I would like to get some suggestions on what gear ratio I should run. I will not be racing or going down the strip with this car. The type of driving I am looking for is being able to have that torque to screw around in the streets and not running high RMP going 70 mph down the highway. With a 1000hp, I was told 3:75 is a good ratio, but I would like to get more opinions before I order my rear end.

Thank you

what trans?

I will be running a 4l80e

I ran a 3.25 gear with my 4L80E and twin turbo LS2. That trans doesn't have as much reduction in overdrive as the 5/6 speeds or even the 4L60s. With that much power I didn't miss the lower gear and appreciated the extra drop in rpm's going down the freeway. I wouldn't go lower than a 3.50 max with the auto. A T56 likes a 3.70 gear as it has a much taller 6th gear.

I did not plan on going any lower than 3:70, but do you think with a 3:70 I will have that torque to launch of the start?

You have 1000 hp......:lol:

exactly. :lol: There's about a 300 rpm difference cruising down the freeway between your 3.70 gear and a 3.25. That's guessing tire height at 27", and using the overdrive gear of .75 in the 4L80E. That trans does not get as much drop in overdrive as the other auto overdrives or any of the 5/6 speed overdrive tranny's.

You have so much power the taller gear will probably help it hook at higher speeds. You will not hook it at lower speeds anyway, so the lower gearing just makes it worse. I wanted the lower rpm's cruising down the road; doesn't sound like much, but the drop really made cruising a lot nicer.

Maybe look at the gear ratio as traction control. Motors usually have a cruising sweet spot, once that's determined gear it accordingly? You might also prepare yourself to change ratio's once you get some seat time in the car.

:thumbsup:

I'm going to run the same engine as we do in our sand rails.

http://i548.photobucket.com/albums/i...i/P5260604.jpg

http://i548.photobucket.com/albums/i...i/P5260605.jpg

http://i548.photobucket.com/albums/i...i/P5260606.jpg

There's a couple of fun toys! Any video? :thumbsup:

Dude, I bet your car will cost less to build than the sand rails. One of the chassis guys I dealt with was a builder of sand rails from scratch---200k for a turbo'd ecotech 4 seater, evidently, was a fair price. He was doing a couple of them a year. I guess when the shocks are 5k apeice and you need 8 to ten of them--or something like that, it adds up quickly.

I've been in quite a few cars with 1000 or more HP which were street drivers. Most all of them had 28 to 28.5 inch tall tires on the rear (dual purpose street and strip type cars) and, if memory serves, most ran between 3.50 to 3.73. Some of them ran as low as 3.20's, but that typically worked in conjunction with stock ratio's of a T400 trans (2.48 first gear low I believe) to tame the launch. They all seemed to do well on freeway with these setups, but these were with tall rear tires. I'm assuming you will have a 9in center section in the car with this power level, so good news is that a gear change, if necessary, won't be a very intrusive or expensive event.

Keep us posted with pics.

Doug

My tires are 315/30/18, so I believe their just under 25.5 inches tall. Would you say with these tires and a 3:75 ratio, I would get that all around purpose car I'm looking for? I have no experience with horse power on the streets. Everything I've ever worked with is off-road, so I appreciate the advice.

Thanks

you'll be running almost 2600 rpms with those tires and a 3.70 rear end at 70 mph, and that's if you use a lock up converter. It'll be higher if it's non-lockup.

That is not what I would consider great rpm's for cruising, but it's doable.

with that much power the last thing you need is a lot of gear especially with that short tire. I would be down 3.42, 3.30

I believe I have made up my mind. I'm going to order my rear end with a 3:50 gear ratio and go from there. From everyone's advice, it seems to be a pretty decent staring point.

Thanks

I do not know how to add a video on here, but here is a link to a video of one of our cars.

https://www.youtube.com/watch?v=o8LevEkvlhs

Suspension balance is looking good. Thanks for sharing with an old desert rat. :thumbsup:




On YouTube, click the share button, copy the code.
On Lat G click the green film icon and paste the code so it looks like this:
YOUTUBE]http://youtu.be/o8LevEkvlhs[/YOUTUBE
(I cropped the brackets for display)
Then remove the forward slash and everything left of it:
YOUTUBE]o8LevEkvlhs[/YOUTUBE

Good God Almighty that looks like fun....

Awesome!! :thumbsup:

3.42 or 3.50 will work in a high power turbo app. A low numerical gear, can cause lugging in overdrive / low load circumstances. Conversely, too high numerical a gear will usually zing the motor right to rev limit--especially TT LS motors that are so rev happy.

Most modest NA apps with 26" tall tires like 3.73 gear ratio.