: who makes a bigger crank pully



1MEANV
02-09-07, 06:18 PM
i am looking to find who makes a bigger crank pully for the v. i have a 2005. i want to get more boost from my maggie. already have the 2.6 so now i want to change the crank pully to a bigger one. any info would be great.thanks guys.

rand49er
02-09-07, 11:03 PM
i am looking to find who makes a bigger crank pully for the v. i have a 2005. i want to get more boost from my maggie. already have the 2.6 so now i want to change the crank pully to a bigger one. any info would be great.thanks guys.Try ECS (East Coast Superchargers). They have an 8" crank pulley that I believe is an overdrive pulley. (They get about $500 for the darn thing.) The reason that I say "I believe" is that I don't know what our stock pulley is. I've heard it's 7.335", but I want confirmation. If confirmed, this would mean a 9% increase in drive speed (i.e. maggie flow). Going from a 2.8" to a 2.6" front drive pulley is only a 7.7% increase. Staying with the 2.8" and going to the 8" crank pulley would mean less liklihood of slip, too, with a 1.3% increase in flow over just going to the 2.6" alone.

Of course, there is the issue of overdriving the accessories by that 9%. Since I tend to upshift at much lower RPMs compared to others and depend on the fantastic low-end torque of our LS6 engines, this is not an issue whatsoever for me.

Another option is to have the maggie's rear pulleys changed to ratios that would produce higher boost. However, I believe it was Chef that tried having this done by Magnuson, and they refused. I don't understand this because the guys on either the corvette forum or the ls1gto forum or the ls1tech forum (I can't recall which) have had success going this route.

In any case, let me know how you proceed with this as I'm VERY INTERESTED!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!

1MEANV
02-11-07, 07:52 PM
bump

VDiddy
02-11-07, 09:35 PM
I have a bigger crank but no likey it pullied. :cool2:

rand49er
02-11-07, 09:42 PM
I have a bigger crank but no likey it pullied. :cool2:Yeah, but if your rear end is too loud with smelly exhaust, a bigger crank won't help much.



(I can't believe he said that. Did he really say that?)




:histeric:

VDiddy
02-11-07, 10:05 PM
I think I violated the "thou shalt not drink and post" law. In all seriousness 1MEANV, I have been looking for an aftermarket crank pulley for a long time, mostly because I wanted a better quality one. I couldn't find one and I don't think anyone makes one. For your sake I hope I'm wrong. Good luck.

rand49er
02-12-07, 07:31 AM
Here's just one of the many threads discussing this by the GTO guys. What's not clear is does this $500+ 8-rib pulley for the LS1 fit the LS6 and line up properly.

http://www.ls1gto.com/forums/showthread.php?t=125975&highlight=ecs

Luna.
02-12-07, 03:00 PM
Try ECS (East Coast Superchargers). They have an 8" crank pulley that I believe is an overdrive pulley. (They get about $500 for the darn thing.) The reason that I say "I believe" is that I don't know what our stock pulley is. I've heard it's 7.335", but I want confirmation. If confirmed, this would mean a 9% increase in drive speed (i.e. maggie flow). Going from a 2.8" to a 2.6" front drive pulley is only a 7.7% increase. Staying with the 2.8" and going to the 8" crank pulley would mean less liklihood of slip, too, with a 1.3% increase in flow over just going to the 2.6" alone.

I think I mistyped earlier. Based on what Andy mentioned to me, the stock balancer on an LS-6 is 7.25" and he often upgrades to an 8.00". That was what I based my estimates on in terms of boost.

For me, there was NOT a significant difference in rwhp/rwtq. It is higher with the 8" balancer, but it's not THAT much higher.

rand49er
02-12-07, 05:36 PM
I think I mistyped earlier. Based on what Andy mentioned to me, the stock balancer on an LS-6 is 7.25" and he often upgrades to an 8.00". That was what I based my estimates on in terms of boost.

For me, there was NOT a significant difference in rwhp/rwtq. It is higher with the 8" balancer, but it's not THAT much higher.Please elaborate. You mean that you didn't get 10% more boost (8.00" divided by 7.25")?

Several people here have posted that they get a real significant increase going from the 2.8" front pulley to the 2.6" ... like 40 RWHP or something ... and that's only 7.7% increase in boost assuming no slip but slip seems to be a problem with some guys. The 8" crank pulley gives more boost, but you didn't see it in your dyno numbers?

This is good stuff, Luna ... I appreciate your input here. :thumbsup:

Luna.
02-12-07, 07:24 PM
Please elaborate. You mean that you didn't get 10% more boost (8.00" divided by 7.25")?

Several people here have posted that they get a real significant increase going from the 2.8" front pulley to the 2.6" ... like 40 RWHP or something ... and that's only 7.7% increase in boost assuming no slip but slip seems to be a problem with some guys. The 8" crank pulley gives more boost, but you didn't see it in your dyno numbers?

This is good stuff, Luna ... I appreciate your input here. :thumbsup:

Apologies, I wasn't clear. :worship:

What I was referring to was the 8.00" crank balancer, with 2.8" pulley, vs. the stock balancer with a 2.6" pulley. Personally, I did NOT experience a significant increase in boost or rwhp/rwtq when comparing these setups. The 8.00" balancer did yield higher numbers, but they weren't by a significant amount.

From the stock balancer vs. 2.8" pulley, oh, very much so was there a significant increase. If memory serves, my gains were ~15-20 rwhp and ~45 rwtq (both after dyno tune) when comparing the stock balancer vs. the 8" balancer (both with the 2.8" pulley). Those are peak numbers by the way.

As stated before, however, the entire rwtq curve shifts up. It's a HUGE improvement at every RPM--one that you can not only feel, but one that shoves your back into the seat when you ease on the throttle; you can just feel the tires chewing up the pavement. :) :thumbsup:

As far as peak boost goes, similar to what I said in a previous thread, peak boost just isn't constant for me. It seems to jump around from time to time. At times, I get a max of about 7.5, but I've seen it as high as 10 before. 7.5-8 *seems* to be the most consistent boost pressure I get though.

Hopefuly, I explained that a little more clearly. :)

NOTE that the results above are in no way representative of what anyone else might get, even under similar dyno situations.

rand49er
02-12-07, 10:24 PM
... What I was referring to was the 8.00" crank balancer, with 2.8" pulley, vs. the stock balancer with a 2.6" pulley. Personally, I did NOT experience a significant increase in boost or rwhp/rwtq when comparing these setups. ...Okay, that I understand since the increase in boost should be about 2.6% (10.3% -7.7%).

rand49er
02-12-07, 10:27 PM
... From the stock balancer vs. 2.8" pulley, oh, very much so was there a significant increase. If memory serves, my gains were ~15-20 rwhp and ~45 rwtq (both after dyno tune) when comparing the stock balancer vs. the 8" balancer (both with the 2.8" pulley). Those are peak numbers by the way. ...Okay, this I understand, too, since this is the 10.3% increase going from the 7.25" to the 8" crank pulley (8" divided by 7.25").

rand49er
02-12-07, 10:37 PM
... As far as peak boost goes, similar to what I said in a previous thread, peak boost just isn't constant for me. It seems to jump around from time to time. At times, I get a max of about 7.5, but I've seen it as high as 10 before. 7.5-8 *seems* to be the most consistent boost pressure I get though. ....I wonder if you're getting some slip still, even with the bigger crank pulley. Do you notice any belt dust anywhere?

Thanks, again, Luna. You da man!!! :highfive:

Say, where is that 1MEANV, anyway? I bet he's off getting a new crank pulley and not telling us a dang thing! Shame on you, 1MEANV. C'mon, fess up ... you're putting down 700 RWHP now because of this ... c'mon, tell us ... :thepan: . You owe us, 1MEANV. You owe us, you stinker. ;)

Luna.
02-13-07, 01:29 PM
I wonder if you're getting some slip still, even with the bigger crank pulley. Do you notice any belt dust anywhere?

Thanks, again, Luna. You da man!!! :highfive:


Perhaps, but I don't think so. It hasn't showed up on multiple dyno runs (unlike when I had the 2.6" pulley). One variable that seems to make the boost vary is outside temperature. :confused: