I would definitely go with the setup that provides more belt wrap or contact area. Slippage seems to be a marginal issue with these setups.

Slippage not only decreases boost over time, it also results in wasted energy in the form of friction or heat.

I say go with a bigger primary pulley.

 

But of course...

I'll make sure I have my meth working by then so I can get a little bit more torque out of this engine...

 

crazy numbers! im so damn tempted to get the smaller pulley on there 2.87. so damn tempted!

btw! thats crazy with the cats you ended up putting those numbers down. im running test pipes right now, and im thinking going to high flow cats just to reduce sound since my hks tru duel is retarded loud.

i mean , when you were on your stock block i know shawn said also try to stay away from the 2.87 because you can really tear apart your internals ... BUT ITS SO TEMPTING

 

Well...its actually a single cat vs the usual dual setup...see Motordyne XYZ Pipe...I'm running ART pipes where the cats usually are...

And...well, the reason I have this built engine is because I burnt a piston/rings on my stock block...so running the 2.87 is fun, but be prepared if the engine blows...

 

nice

this setup is very similar to what I have in mind..
my aim is also 500+ whp

but why not IPP STG 1 ?
and also, I was thinkin' about going stock CR. any toughts about that?

 

If you are going for higher HP #'s on a vortech setup belive me stay at a minimum of 9.5:1 CR.
When i build i am going to stay at the stock 10.3:1 CR, upgrade to a T-trim head unit,add cams and throw a 150 shot of No2 when needed for good measure.

I have driven a vortech equiped Z with a built short block,8.8:1 CR setup with a 2.87 serp pulley. It was doggy as hell and had no throttle response in the lower rpm range. I let the owner of that Z drive mine and he could not belive the difference in how snappy it was "we both were pulling about the same boost numbers in both Z's". I told him one of the largest factors was that his built engine was setup with such a low CR and that his engine was optimaly built for a turbo setup.

 

I picked Stage 2 IPP because I wanted to S7 cams, mostly...Stage 1 should get the job done as well...

As for running with the stock compression ratio, I suppose it may still be ok; pharmd had 9.0:1 CR built engine for his 500whp build, and my 9.5 CR build has the highest compression for a built Vortech Z that I know of; that being said, str8dium ran about 500 whp (for dynojet since he did his dyno on dyno dynamics) with a stock block, so maybe a built engine with forged pistons with stock CR may hold up to around 17psi, which is probably about the max you can get out of the Vortech kit...particularly since the torque isn't mind blowing like turbo kits...

Well you and JetMech try the stock compression built engines, if it holds up my next shortblock (which i hope I will never need lol) will be stock compression too...

 

maybe a noob question,
but is there any "rule" for wich CR can hold a said psi of boost?,

Edit: and also how do u like the Vortech power? any regrets? would u go turbo?

 

I am running stock CR on a built motor with a T-trim. I have yet to tune tho as i am just over the break in miles now just need to get my new exhaust and and intake mani. Should be all done in the spring, shooting for 20psi with my ATI super damper!

 

Bottom line: If I didn't have to have a CARB number here in SoCal I would probably have done turbo....like that immediate torque ...

But I am very happy with the power...I don't think I can handle more than 500whp/500torque without some sort of traction control...

As for the rules of CR vs psi, most of the info on this forum is for turbos, so I don't know if that is equivalent to SC...

 

Good luck with that ...are you worried about overspinning the blower?

 

Nah. Ive been doing my research and judging from boogers all cog set up and quamans 8 rib set up, the 6 rib slips so much overspinning shouldnt ever be an issue. Quaman made 14psi on an 8 rib pulley set up that spun his blower to about 43,000 rpms i believe, while most ppl have a hard time hitting that on a 6 rib pulley set up that is supposed to spin the blower at the max rpm. With the 6.78" ATI, 3.25" J/S, 34 and 28 cogs my blower is supposed to be spinning around 60,000, but i dont think it will ever see that due to belt slip. Also the V1 blowers have a different internal gearing and will actually spin around 2,000 rpm slower than the V2s with the same pulley combo.

 

BTW, BIG congrats on ur set up Makes me even more anxious to get mine done

 

your "research" is from projects many years old. They didnt even have revised pulley setups back then, and those 2 are both home made 1 off setups.

I was making 17psi with the standard belt routing, no slip. 20 psi with that crank pulley will be no problem. If you are slipping, you dont have your setup installed correctly.

 

Well i think some slip is inevitable, but if i am wrong and i do overspin the blow n it goes bad, all the more reason to try to stuff a v7 YSi in there!

 

I couldn't find anything about the BPV in this thread...

so wich BPV/BOV are you using?

 

I'm using the standard Vortech BPV; Pharmd called Vortech about how much the standard BPV can handle, and Vortech said it can handle up to about ~20psi

 

may I ask; did you upgrade your axles?

and cams?

EDIT: I Re-read the thread and found out about the cams, wich was the reason you went with stage 2 = S7 cams

 

I have never heard of anyone needing to upgrade their axles. BC Stage 2 cams are also a fine choice.

 

So what did the car do in the 1/4 mile?