stepping up pullies

**Readyross** · 03-22-2003, 01:21 PM

I have a vortech a trim and was curious if i could change the original 6 rib 3.33 to a 6 rib 2.95. Will this work good or will it just slip under high boost. Or should I just get a 7 inch crank, and what kind of boost do you think I would get, thanks!

**bumblebee03** · 03-22-2003, 01:38 PM

you should not have a problem with that set up,, a 7" crank pulley will definitely help as well, should give you an additional 2lbs of boost,,,,, I am waiting for my 8 rib pulleys from vortech,,, so when I get them,, I think I have a 2.75 or smaller,, I cant remember,,,, pulley if your interested... Bee

**Readyross** · 03-23-2003, 07:20 PM

I went on vortech's site and they had that impeller calculator and when I did it, it basically said that anything smaller than the 2.95 would be faster than the efficiency rating for the a trim. do you think thats just to cover there butts or could you possibly do somthing like a 7 inch crank and 2.75 pulley. Hey bee are you getting a 7 inch crank with the 2.75 too.

**midnight** · 03-23-2003, 08:24 PM

It is not to cover their butts.Their butt is covered when you remove the stock pully as evidenced by the seal(epoxy)broken if it is returned for any warranty work..A 7" crank pulley & a 2.95 pulley at the rev limiter would be turning 51165..max efficiency on an "A" trim is 40k & absolute impellar speed is 45k..any thing above 40-45 you're just building heat..and you know what that can do for an engine...

**bumblebee03** · 03-23-2003, 09:54 PM

I got the 7" with a 2.95 ,,, the pulley I had on my A trim was a 2.62... bee

**Readyross** · 03-25-2003, 01:17 PM

well i guess that a 7 inch crank and a 2.95 pulley would be ok but be careful riding the redline. But won't you make more HP at lower rpm's. Would this be ok or am I missing somthing.

**blue89gt** · 04-03-2003, 07:33 PM

i had the 2.75 (seeing 6psi denver) with the stock crank pulley and my boost over the 3.33 at a lower rpm picked up 30tq at 2700 rpm and and 60tq 3800 rpm, on the hp side 10 hp at 3000 rpm and 45 hp at 5200 rpm.. i hope that helps. that was in summer with no real cool down on the car.

so stock was 207.6hp and 267.3tq
a-trim 3.33 268.1hp and 327.6tq
a-trim 2.75 305.7hp and 346.9tq

the caqr had 212,000 miles on it and when i put the 2.62 pulleyt on there the car was faster, unfortunatley I did not make it to the dyno. but i hope i helped.

**Readyross** · 04-03-2003, 10:18 PM

nice was the 2.62 a six rib , did u have trouble with any slippin

**bumblebee03** · 04-03-2003, 11:36 PM

Yes it is a 6 rib,,, I really did not have much slippage,, but I just put on a 8 rib pulley,,, 2.95 with a 7" crank,,, I have not taken the car out yet though,,, hoping to see at least 10 lbs of boost up here in Denver 5500 ft,,, I will let you know,,, If you are interested in the 2.62 let me know,, Bee

**nstycpe93** · 04-04-2003, 11:45 PM

on my previous a trim, i had a 2.75 pulley and 7 on crank with power pipe.
had 11/12 lbs of boost showing. i didnt have any problems with the little blower and it went thru 2 yrs this way. averaging almost 125 runs before i sold it. it is still running and has never been down for repair.

you might want to check with www.aspracing.com they also have pulley combos that might be a little less then vortech.