Best Upper Pulley Size for Apten

[jfclague]

Has anyone determined the best upper pulley size with the Apten supercharger upgrade?

I am currently running with 2.93, should I drop to 2.8 before going with the Apten?

Thanks,
Jim

 

[Fast01Cobra]

I don't think that the pulley size will matter that much. The increase should be about the same. IE. if you dyno @ 420rwhp with your current config, it should see around 440 - 450. If you dyno at 440 say with a smaller pulley, you should see around 460 - 470. I'm speaking theory here, so don't take those numbers to be exact. I'm trying to point out that your gain should be about the same. I would recommend going to the 2.8 if you are not concerned with warranty and such, but get an aux. idler.

 

[jfclague]

Originally posted by Fast01Cobra
I don't think that the pulley size will matter that much. The increase should be about the same. IE. if you dyno @ 420rwhp with your current config, it should see around 440 - 450. If you dyno at 440 say with a smaller pulley, you should see around 460 - 470. I'm speaking theory here, so don't take those numbers to be exact. I'm trying to point out that your gain should be about the same. I would recommend going to the 2.8 if you are not concerned with warranty and such, but get an aux. idler.

Fast01Cobra,

Thanks for the info. I am currently at 455 and with all the mods I have already done, I think warranty issues are blown. If I do switch to the 2.8, I will definately get the idlers.

Thanks
Jim

 

[SVTdubs]

the hp will be about the same but the tq is a huge difference. I have a 2.76, see sig for numbers without the apten. Apten numbers will be here Dec 22. Tq is what gets these bricks moving.

 

[CobraBob]

I have a 2.90" RR upper now, but will probably change to a 2.80" RR after I install the Apten blower.

 

[bross03cobra]

FAST01,
I see you put 4:10's in. HOw do you like them and do you still have the IRS. I was thinking of going to 4:10's or 4:30's in mine but didnt want to go to a solid. What did the gears run you if you dont mind. I would greatly appreciate any help......Thanks, Bill

 

[AustinSonicBlue]

so 2.8 upper, no lower, NGK TR6's ok with 93 octane pump gas?

i'm in!

 

[Fast01Cobra]

Originally posted by bross03cobra
FAST01,
I see you put 4:10's in. HOw do you like them and do you still have the IRS. I was thinking of going to 4:10's or 4:30's in mine but didnt want to go to a solid. What did the gears run you if you dont mind. I would greatly appreciate any help......Thanks, Bill

Bill,


I really like the 4.10s. They haven't hurt me on the track yet, but I maybe getting close to Redline when I finish my mods. I would highly recommend staying away from 4.30s as you will be out of RPMs with them.

BTW I still have the stock IRS.

Good luck....

 

[bross03cobra]

Fast,
Thanks for the info, I appreciate it. The 4.10's will be the way I go then. Did you install them yourself or dealer installed? Thanks....Bill

 

[Fast01Cobra]

Originally posted by bross03cobra
Fast,
Thanks for the info, I appreciate it. The 4.10's will be the way I go then. Did you install them yourself or dealer installed? Thanks....Bill

I had a local performance shop install them. Don't forget that you will either need a speedo calibrator or and aftermarket chip to compensate for the gear change.

 

[jguerrero]

I asked Bryan from Apten the same question over the phone he told me that there was not much of a difference from the 2.90 to 2.80 ( i think he said a couple more horsepower, and 6 more rwtq). I am goign to stick with my 2.9RR, its worked this far, why mess with it over a few measily numbers.

another thing, I have not had any belt slip so far, and I do not have an idler sytem. Goign to a 2.8, I think you would have to...

 

[JKD COBRA]

I say go with a 2.80. I have used the 2.93 and the 2.80. The 2.80 is much better, more hp, and a lot more torque. I would never run a 2.93 again.