Vortech Experts...Pulley Swap Question.

94GTLaserRC · Aug 8, 2009

As mentioned briefly in my "WOT" post, I may be switching out the stock pulley. I am not 100% sure that I currently have the stock one, but Vortech did service it once and didnt say anything about it, so IM fairly sure it IS the stock one.

Anyway, since Im running the 8.5:1 comp CHP and 185 AFR's, it's going to be hard to make boost. Any suggestions on which pulley to get (and the corresponding belt) that will give me some more boost, but yet not spin the Vortech "crazy"...I guess a "happy median"?

Thanks
RC

turbogt · Aug 9, 2009

Thats a pretty open question.. I think you need to narrow down what you want before you will get any decent answers..

A 3.00 pulley should give you somewhere in the vicinity of 8-9# with your setup..

94GTLaserRC · Aug 9, 2009

turbogt said:
Thats a pretty open question.. I think you need to narrow down what you want before you will get any decent answers..

A 3.00 pulley should give you somewhere in the vicinity of 8-9# with your setup..

Ok.

First...What is the diameter of the stocker?

I have a low-comp 331 with AFR 185's. I have gone WOT only once so far (breaking in engine), and didnt get to see the boost, but at near WOT, Ive only seen about 5# boost. With my stock engine before (just the MAF, TB, and Intake were upgraded), I could easily see 10-12. (Drop off is obvious with current setup)

Im not sure what all the interval sizes are, but I would like to be able to see 10-11# with this setup, but not at the risk of messing up the S/C. So I guess the question would be which pulley size would give me a nice balance of power upgrade without putting the S/C at "high risk".

Hope that clarifies it.
Thanks
RC

turbogt · Aug 9, 2009

94GTLaserRC said:
Ok.

First...What is the diameter of the stocker?

I have a low-comp 331 with AFR 185's. I have gone WOT only once so far (breaking in engine), and didnt get to see the boost, but at near WOT, Ive only seen about 5# boost. With my stock engine before (just the MAF, TB, and Intake were upgraded), I could easily see 10-12. (Drop off is obvious with current setup)

Im not sure what all the interval sizes are, but I would like to be able to see 10-11# with this setup, but not at the risk of messing up the S/C. So I guess the question would be which pulley size would give me a nice balance of power upgrade without putting the S/C at "high risk".

Hope that clarifies it.
Thanks
RC

I believe the stocker is 3.33 for 8#..

I don't know what size crank pulleys they come with.. I have never measured mine..

There is a rpm calculator the blowers online somewhere, or, you can call vortech...

If you have the fuel system and tuning abilities to support it, I would buy a 2.75 and throw it on there.

That should get you up around 12#.. Maybe a hair more..

Pulley sizes are.....

3.33
3.15
3.125
3.0
2.95
2.85
2.75

Now that my wideband is up and running, and I'm running nice and fat at WOT, I might drop down to a 2.95 for awhile...

turbogt · Aug 9, 2009

I was also curious what your CR is and why you chose to go low compression??

I plan on running 20#+ but am still going to keep the Compression Ratio at 9.25:1 to keep the motor responsive and torquey...

94GTLaserRC · Aug 9, 2009

I measured the outer diameter now and it's just under 3.5". I cant measure inside because the belt is on it. Im fairly sure it is NOT lower than 3.15. Now I would just need to know what size belt to get with it. I dont know if the same belt would work by just lowering the tensioner pulley a bit more.

I got the low comp becaue I bought the ENTIRE CAR from Roger for a really good price. The engine was already in it...the CHP almost brand new engine, along with the entire new Tremec 5 speed and lots of other goodies. For the price I got it for, i was not going to worry about the low compression.

Anyway, that along with the 185's is going to cause me to really spin it to get 8-10 pounds.

What's the best/easiest way to remove the pulley? An air wrench with the belt on it?

Thanks
RC

ProKiller · Aug 10, 2009

your still running the stock 3.33 pulley. i just put a 2.95 on my car. i did the calc tool and i'll run out of RPM on the blower at about 5600. You have to watch that. I would think with your setup that would probably be the concern before you hit your 10-11#s of boost. i wouldn't go any smaller than a 2.95 as that seems to be the sweet spot to me. its small enough to give you some good boost numbers, and yet large enough that belt slip isn't a problem, and won't over spin the blower.

94GTLaserRC · Aug 10, 2009

ProKiller said:
your still running the stock 3.33 pulley. i just put a 2.95 on my car. i did the calc tool and i'll run out of RPM on the blower at about 5600. You have to watch that. I would think with your setup that would probably be the concern before you hit your 10-11#s of boost. i wouldn't go any smaller than a 2.95 as that seems to be the sweet spot to me. its small enough to give you some good boost numbers, and yet large enough that belt slip isn't a problem, and won't over spin the blower.

That's some good info. Wes suggested I keep what i have for now and get her all tuned up first.

I read the Corral link on the S-Trim to Si upgrade. Sounds really good to me for the price. Im wondering if price is not a "big" factor if that would be a better option than the pulley swap.

I didnt think the pulley size that small of an increment would make such a big difference.

RC

94GTLaserRC · Aug 13, 2009

I decided to go with just a one increment pulley upgrade...3.12" from the 3.33. WIth the 185s and 8.5:1 comp, this should help get me 2# more or so for only $100 price.

Thanks'
RC

Black Stampede · Aug 14, 2009

What kind of power numbers are you looking for rc?

94GTLaserRC · Aug 14, 2009

My combo is capable of over 450 to the wheels. I much prefer 400-425 with SOLID tune and very safe. I wanna switch the pulley though so I can get the boost down lower in the RPM band.
RC

Black Stampede · Aug 15, 2009

94GTLaserRC said:
My combo is capable of over 450 to the wheels. I much prefer 400-425 with SOLID tune and very safe. I wanna switch the pulley though so I can get the boost down lower in the RPM band.
RC

I like your emphasis on solid tune. I have to ask though, would your really be ok with this setup only making an extra 15 to 40 rwhp over your old combo? I realize you did all the cleanup and odds and ends, which is awesome, but were you not really looking for a whole lot more power?

turbogt · Aug 15, 2009

ProKiller said:
your still running the stock 3.33 pulley. i just put a 2.95 on my car. i did the calc tool and i'll run out of RPM on the blower at about 5600. You have to watch that. I would think with your setup that would probably be the concern before you hit your 10-11#s of boost. i wouldn't go any smaller than a 2.95 as that seems to be the sweet spot to me. its small enough to give you some good boost numbers, and yet large enough that belt slip isn't a problem, and won't over spin the blower.

I'm waiting for my 2.95 to show up also.. Can't wait to see what she does..

I got mine for $70 shipped

94GTLaserRC · Aug 15, 2009

Black Stampede said:
I like your emphasis on solid tune. I have to ask though, would your really be ok with this setup only making an extra 15 to 40 rwhp over your old combo? I realize you did all the cleanup and odds and ends, which is awesome, but were you not really looking for a whole lot more power?

i was barely at 350 with my old setup. The original 389 was with an AFR over 13.5:1, so when we added the FMU, it was down to about 340. Never dynoed it again. AT 425, im still a good 75 over previous. Having said that, I have some other factors playing in.

I have the SNow Meth Kit. If I can get that on, I can bump up the timing (and still be "safe") and get closer to 450. Wes has told me that we can still be "VERY SAFE" at 450 with that combo and Meth Kit. I have no problems with that. As I run the car and send Wes the Data logs, he will be keeping a close eye on the safety parameter, AFR, Spark, Timing, etc.

Ill go as far as he says is good while keeping it below the limits.

RC

Black Stampede · Aug 16, 2009

Oh. I just always assumed you were running 385 rwhp.

94GTLaserRC · Aug 22, 2009

Got the pulley in, removed the old one, and what do you know...it's the same size. Apparently I already had the 3.12 on it. Guess Ill step down to the 3.00, or 2.95 not slip one. to get a couple extra pounds.
RC

turbogt · Aug 23, 2009

94GTLaserRC said:
Got the pulley in, removed the old one, and what do you know...it's the same size. Apparently I already had the 3.12 on it. Guess Ill step down to the 3.00, or 2.95 not slip one. to get a couple extra pounds.
RC

oops lol.... It didn't say what size it was right on the pulley??

Mine is engraved in it..

I just put my 2.95 on but I need a shorter belt I'll have the new belt tomorrow so we'll see what she's got..

I used the rpm calculator, and 2.95 is the smallest we can run without actually overspinning the blower, although, Vortech is pretty conservative on their rpm ratings and it wouldn't scare me to spin it a little fast, especially with how rarely I ever go to redline....

94GTLaserRC · Aug 23, 2009

turbogt said:
oops lol.... It didn't say what size it was right on the pulley??

Mine is engraved in it..

I just put my 2.95 on but I need a shorter belt I'll have the new belt tomorrow so we'll see what she's got..

I used the rpm calculator, and 2.95 is the smallest we can run without actually overspinning the blower, although, Vortech is pretty conservative on their rpm ratings and it wouldn't scare me to spin it a little fast, especially with how rarely I ever go to redline....

NO markings were on it. If IM using the 3.12 now, IM hoping I can go to the 2/95 without a new belt. If I need it, so be it. Calling tomorrow for exchange.

WILL BE SELLING AN ALMOST NEW SNOW STAGE 2 KIT IF ANYONE WANTS!

turbogt · Aug 23, 2009

94GTLaserRC said:
NO markings were on it. If IM using the 3.12 now, IM hoping I can go to the 2/95 without a new belt. If I need it, so be it. Calling tomorrow for exchange.

WILL BE SELLING AN ALMOST NEW SNOW STAGE 2 KIT IF ANYONE WANTS!

I made the same swap and most definately need a new belt.. I was surprised how more loose it was...

kreymis · Aug 24, 2009

what size belt or what part # do i need to get a 2.85 on?

Vortech Experts...Pulley Swap Question.

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