stevieturbo

Am I right in assuming that if you gear a blower to spin at a certain rpm/airflow, say for example for 500bhp, if all things work out well, the engine should be capable of making that power ?

I ask as I got a couple of pulleys made for my LS1/YSi trim, FMIC etc.

I have a 8.25 crank, and 4" blower, and a 3.65" blower

This will shift a certain amount of air/rpm. What sort of potential on pump fuel would each pulley have ? Approximate figures just on a relatively std 346 LS1

My intention is to use the 4" pulley on a stock 01 LS1 with Pace Headers ( hoping it will give around 8psi ? )
I'll try the 3.65" when I put together a low compression motor, with ported heads and GT2-3 cam.

Thanks, Stevie

Pro Stock John

iTrader: (34)

8 rib or cog?

The base LS1 Vortech kit uses 8.00 and 3.12 pulleys. Good for like 9 psi. Why not use the 3.12 blower pulley?

stevieturbo

Mine isnt an F-Body. its been a mix n match of parts. My layout is more akin to a Holden Commodore

I originally got a 50mm cog setup from CAPA and it wouldnt fit, and they were useless in offering me a solution. Cog belts just arent made in sensbile lengths. How they ever sold it to me as a kit is beyond me.

So I got ASP to re-cut my 86T crank pulley for ribbed belts and blower pulleys to suit.
I ended up with a 14 rib crank, 8.25" and I had them make me 2 x 12 rib blower pulleys, estimating 8-9psi std LS1 and 13 psi for the other ( hence the 4" and 3.65" ). I had the room, so just went for widest pulleys I could for more belt options.

I appears there are no 12 rib belts available in the 64" length I need though.

I can get a 10 rib, so will probably use that. I have tried 2x6 ribs just to hear what the blower would sound like ( Ive only just got the engine running over the past week or 2 )

Some vids :-)
http://www.putfile.com/media.php?n=stevieturbo-blower
http://www.putfile.com/media.php?n=s...rbo-blowerspin

Pro Stock John

iTrader: (34)

8.25 and 4.00 sounds like 6-7 psi, but I could be wrong.

With mine I am:
8.00/2.85 ~21 psi
8.00/2.95 ..18 psi guess
8.00/3.12 ... 15 psi guess

So I figure
8.00/3.33 ~ 12 psi

stevieturbo

Cool. That'll give me a good starting point anyway. At what rpm's are you basing maximum boost ?

I'll maybe get them to make me a couple of smaller pulleys then so I dont ahve to wait about on them.

stevieturbo

Turns out the 8.25/4" is giving me just shy of 9psi at 6000rpm. ( 160kpa ). Just using a 6 rib belt for now until I can get a wider belt.
I tried 2 x 6 ribs together, and they lasted about 15 miles before one got shredded. Luckily didnt do any damage though.
Im quite impressed alread at how the engine goes. Normally aspirated it felt good. Now with a bit of boost it feels sooo much better.
It does seem to pull much harder from about 5000rpm though. Haven't went much beyond 6000rpm really..

Still need to work on fuelling a bit. I also have a bit of a dead spot every time I change gear, and re-apply the throttle.
I think its too much accelerator pump enrichment as opposed to not enough?? What way is that type of thing set up on other aftermarket ecu's on an LS1 ??
Mine has 4 bands.
0-1500
1501-3000
3001-5000
5001+

Cheers, Stevie

Im almost tempted to try the smaller pulley I have on the std engine, but Im guessing that would be a very bad idea...