Boost/Pulley help

[97stanger]

Well, I am currently in the process of building up my motor. The motor will consist of MMR stage 3 ported/polished PI heads, CMS stage 3 blower cams, ported Edelbrock Victor Jr. EFI manifold, Vortech SI Trim, Paxton front mount, MPH power pipe, slp longtubes, bolt ons, built auto, 3500 stall, etc. Now....before I built my motor I was running an SQ trim with paxton front mount, MPH pp, and a 3.12 pulley. So this is the current stuff I have (except I am upgrading to SI trim). My question is, considering i am forging out my motor, what do you think I should do to play around with my pulleys? I dont want to build this whole motor, keep what I had, and be at 8psi or something. Before I believe I was seeing about 12 psi, but that was through stock heads and not blower cams and a stock PI manifold. Can I go any lower on a 6 rib, or is 3.12 about the smallest? What would you guys suggest doing? thanks

 

[NERD]

you can go with RR 2.9" or 3" if you have a good belt but I wouldn't advise it. Don't worry about how much boost you'll see. In fact the higher your boost numbers the worse off your setup will actually be. Stick with your pulley you have now and if you want to increase it, go with a I/W 10% OD Balancer. Then jump to smaller pulleys. The SI will be maxed out at 3" with an ODB.

I run a 3.12 and see more boost than I should and I'm sitting at 600rw through a manual. If you have an Auto, don't pay attention to Hp numbers, especially if you have a stall.

 

[97stanger]

so mike would you suggest just going with the I/W 10% OD balancer right off the bat? What is this actually doing?

and btw, i talked to Jim for a while, i ended up going with the stage 3's

 

[NERD]

The ODB does two things, It increases rotation therefor, increases boost and also helps increase grip of the pulley. I'm running an 8rib which I bought used for $250 and if I ever do switch to a 8rib setup if I pulley down, it's there and I don't have to worry about buying another one. I would see where you're at with power and money and if you're within your goal & satisfaction level; then adjust from there.

Although I'm a little confused by his suggestion of the stg3's, Jim knew I was a little on the conservative side, so maybe that's the difference. Stg3's sound amazing, I just hope your tuner knows what he's doing.

 

[97stanger]

well, it seems to me after reading on some forums that guys were picking up 2-3psi with just putting on the 10% od balancer. Do you think it would make sense to keep everything i have, except just add the 10% od balancer for now, but keep my 3.12 6 rib setup? And you are telling me I can go with the 8 rib 10% od pulley and still run my other 6 rib pulleys?


as for the cams, he said especially with my stall setup and auto he would no doubt go stage 3's. that could make the difference too. And my tuner i go to I feel is the best in NJ. He has tuned my car over 6 times, and I have never had a problem. They also hold the record for fastest 2v on drag radials, the shop is called Big Daddy Performance, so I'm not worried about tuning purposes.

 

[NERD]

I also picked up 2-3lbs. That's all I did was keep my 3.12 6rib and the rest of the 6 rid stuff. The ODB is an 8rib but does not interfere with the 6rib belt.

I never knew (Or put it into my head if I did know) that you where an Auto and that does make more sense why he'd suggest the 3's for you.

 

[97stanger]

sweet, then thats what I'll do. Before the motor goes back in the car just do the 10% od balancer and keep the rest of my stuff. I'll go with the 8 rib balancer. If I dont make nearly what I want to and want to crank up the boost, I can just change the rest of my pulleys to 8 rib and run smaller than the 3.12.


yeah man, I have a built AODE with a BC auto 3500 stall and a custom valve body.


thanks again for the help mike, you da man. my next step is the MMR MOD 900 rotating assembly. should have the money to get this in the next month, two months top. After that sending my PI heads/cams/valvesprings to MMR for their stage 3 port/polish job and assembly. They are also port matching my Edelbrock manifold.

 

[blown98gt]

i've got a RR 8 rib 2.9 pulley and no belt slip

 

[97stanger]

i just dont want to go much lower than my 3.12 because its a 6 rib. the only 8 rib will be the 10% od balancer

 

[blown98gt]

just switch over to an 8 rib setup

 

[97stanger]

i honestly dont think i have to/want to right away. I am going from a car with 400rwhp to mid 500rwhp. I think at first I'm going to just keep what I have and add the 10% od balancer. after the car goes on the dyno and I see where I'm at, then i can eventually add the 8 rib setup. thats why i want to get the 8rib 10% od, so if i do decide to go 8 rib I'm good to go

 

[justinschmidt1]

your boost will drop because of less restriction but I wouldnt worry about that since you should be making a bunch more power even with less boost, but I would do the 10% od balancer instead of the blower pulley to prevent belt slip

 

[blown98gt]

the RR pulleys are amazing and i've not had any belt slip issues with a 10% od bal and a 2.9 pulley on an 8 rib.. just food for thought.. the design on the RR pulleys are very nice and do help belt slippage

 

[97stanger]

definately some food for thought, but I think I'm just going to keep my whole 6 rib setup with the 3.12, and just add the 10% od balancer

 

[justinschmidt1]

go with that and see what happens, you will probably need a t trim upgrade to make some more boost

 

[97stanger]

well im getting the SI, which only flows 50cfm less

 

[justinschmidt1]

ooo good shit

 

[97stanger]

yeah i mean its a no brainer. For $380 you can do the SI trim upgrade. For $1000 you can do the T trim upgrade. The SI trim as i said only flows 50cfm less so to me it seems like an easy decision

 

[CobraObsession]

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