LOST BOOST!?

[spoc8hi]

hi guys, i just put a 5.1 stroker in my stang. before the swap, i made 10-12lbs of boost with my vortech v-1, but now the best i can get is 6-7. is this normal because of the increased cobustion area or do i have a boost leak?

 

[jstreet0204]

hi guys, i just put a 5.1 stroker in my stang. before the swap, i made 10-12lbs of boost with my vortech v-1, but now the best i can get is 6-7. is this normal because of the increased cobustion area or do i have a boost leak?

Losing some boost would be normal with more displacement. Boost is just a measure of restriction. Your engine is breathing more so boost goes down. I'm a little surprised it went down that much, but I guess it is possible. 10 down to 7 sounds reasonable. 12 down to 6 sounds like a little much, but I dunno

 

[SaleenGT2001]

ported heads, cams and LTs will cuase boost drop b/c they allow the engine to flow better

 

[ceracer33]

what they said. ur engine is requiring a lot more cfm to make the same boost as before now. if u did ported heads with the swap then i could see u losing a lot of boost like that. u need more cfm.

 

[speedytang]

Now you need to spin the supercharger harder and yes this is normal that is why they sell Pulleys.

 

[ADRENLN]

holy.....i didnt think you would lose that much with a stroker. i am getting a stroker myself and am not prepaired to lose that kind of boost. might have to pulley down.

 

[ADRENLN]

honestly yours seems a bit excesive.

 

[Green&GoldGT]

I know that extra displacement will lower boost. But isn't extra stroke supposed to increase the speed of the blower?

 

[SilverBullet00]

Just because you loose boost doesnt mean you loose power.

 

[jstreet0204]

Just because you loose boost doesnt mean you loose power.

Exactly! Like I stated earlier, boost is a measure of restriction. If you lose boost because you engine flows more air you have gained power because it isn't working as hard to flow the same cfm.

 

[jstreet0204]

I know that extra displacement will lower boost. But isn't extra stroke supposed to increase the speed of the blower?

Changing the stroke does not change the rpm of the blower.

 

[BennyBlown2v]

Just because you loose boost doesnt mean you loose power.

heh when I lost boost from my intercooler I lost 20rwhp ...all back now + some though hehe.

 

[jstreet0204]

heh when I lost boost from my intercooler I lost 20rwhp ...all back now + some though hehe.

That's a little different though. Your intercooloer not only cooled the air charge causing a pressure drop, it also created a restriction. The opposite of what we are talking about here.

 

[04YELLOWGT]

I lost 1-2lbs with just headers so I could see that happening.

 

[spoc8hi]

thats a relief. i was afraid i had a serious boost leak somewhere. i guess ill just swap the pulley. thanks for all your help.

 

[joshjwc9]

Now has the car been dynoed? Going from a stock block and bottom end to stroked/forged would do that...

Sounds like the little V1 should be given to me and you should step up to a T or YSi trim