Boost

[Renfrick1 83]

I have a question about boost and size pulleys to make it.

How come the same blower will make different boost on different cars. I have a 3.87" pulley in mine and I make around 6 lbs of boost. Isn't it 1/4" drop in pulley size good for 2lbs of boost? So why do I see people running 3.2" pulleys and only getting 7lbs of boost. Wouldn't it be 3.75 " 6lbs 3 1/2" 8 lbs and 3 1/4" 10 lbs and 3" 12 lbs?

I see a lot of difference in Maggie and enforce and even pro charger with the size pulley and what they have for boost with certain pulleys

[AvantSrt8 34]

More than a few reasons.

Different size balances for 5.7's and 6.1/6.4, head work, under/over drive balances, exhaust work, cam choice, etc, all have an effect on engine back pressure which will lead to variations in boost seen.

Without saying how accurately each person in measuring the boost and under what weather conditions.

[1FST4DR 85]

^^What he said^^ lots of reasons....

[Renfrick1 83]

More than a few reasons.

Different size balances for 5.7's and 6.1/6.4, head work, under/over drive balances, exhaust work, cam choice, etc, all have an effect on engine back pressure which will lead to variations in boost seen.

Without saying how accurately each person in measuring the boost and under what weather conditions.

I didn't think about balancers. All three motors have different sizes.

Thanks

[CruzKing 83]

I have a question about boost and size pulleys to make it.

How come the same blower will make different boost on different cars. I have a 3.87" pulley in mine and I make around 6 lbs of boost. Isn't it 1/4" drop in pulley size good for 2lbs of boost? So why do I see people running 3.2" pulleys and only getting 7lbs of boost. Wouldn't it be 3.75 " 6lbs 3 1/2" 8 lbs and 3 1/4" 10 lbs and 3" 12 lbs?

I see a lot of difference in Maggie and enforce and even pro charger with the size pulley and what they have for boost with certain pulleys

Your slow SlowMan. 6lbs, you can get that with a gerbal.

[Renfrick1 83]

Dick

[CruzKing 83]

No CruzKing.

[SRTROB 2]

Kevin Edelbrock claims 1.5 lbs of boost for every 1/4 drop in pulley size for our units , but i have only seen 1 lb per 1/4 drop . I think with the long runner design the unit has a hard time filling the runners and keeping them full. I also think that the Eforce is screaming for more air and a 90mm TB would greatly help .

[Renfrick1 83]

Thanks rob

[nd4topspd 12]

another mystery with mine is on dyno I see 11 lbs boost and on the street I see 13lbs

all I know is its FUN

[CruzKing 83]

Boost is like a boob job cuz......... where the hell did i get that.

[VICHRIS 13]

another mystery with mine is on dyno I see 11 lbs boost and on the street I see 13lbs

all I know is its FUN

John,,,, you still got that Maggie on there?

[BayouTiger 88]

Hell, I only get 7.5 from my e-force on my setup, but it made 650+. If I remember right we tried the last smallest pulley (2.75) and didn't make any more power so we stuck with the 3.00". I would like to get my hands on an 8" lower, but that would be custom. I know some have done them.

Rob's comment makes me wonder about the TB. I'm running the stocker.

[rdrdr90 35]

Hell, I only get 7.5 from my e-force on my setup, but it made 650+. If I remember right we tried the last smallest pulley (2.75) and didn't make any more power so we stuck with the 3.00". I would like to get my hands on an 8" lower, but that would be custom. I know some have done them.

Rob's comment makes me wonder about the TB. I'm running the stocker.

Running the mile like you do, at least an 85 or better a 90 would be a wise investment.