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-   -   does this make sence (https://www.racingjunk.com/forums/showthread.php?t=30577)

melson3086 06-18-2011 04:08 PM

does this make sence
 
Im was running a 7.25-1 sbc with a surcharges 12-14 lbs boost brodix track1 heads comp blower cam 575 lift solid roller the car went 10.20's rebuilt motor went to alcohol this year bumped compression up to 11-1 and 10lbs boost same cam and heads went almost same e/t and same mph 130

melson3086 06-18-2011 04:11 PM

Supercharger sorry used my phone to post this and my phone likes to change my words

maxpower671 06-19-2011 05:30 PM

need more info on engine and vehicle...cam specs...the more the better...

its possible, you have more compression, but less boost....

hard to say how good your 'tune' is?

melson3086 06-20-2011 05:14 PM

Tube chassis 2500lb 355cu sbc bowtie block comp cam 12-704-8 255 262 @50 LS 114 575 575 solid roller turbo 400 4500 stall 3.89 gear 28-10.5 MT's changed from a 26cc dish piston to a 14cc dome piston 2 850 ken Jones alky crabs. the blower is a 420 mega blower 6% under

hotrod1994 06-20-2011 05:57 PM

you gained the compression ive herd (compression gains abut 4% of hp per 1 point of compression like from 10:1 to 11:1 ) some say you gain from 10-20 hp depending on the engine itself but you lost boost you get about 10-20 hp per pound of boost depending on size and cfm of the supercharger so depending on the supercharger itself it may have just equaled each other out

fast75vega 06-20-2011 06:11 PM

sure your carb is jetted right for the alky? what temp you running? we were running mid 9.50's @ 160deg. ... jetted it down and got 180 temp and running 9.43's now

melson3086 06-21-2011 05:31 AM

I know I have the crabs on the fat side I haven't been able to get back to the track to do some tuneing it was the first time out this year and just expected a little better performance but also had the timing locked at only 25 degrees total

maxpower671 06-21-2011 08:23 AM

bump timing up to 30 degrees total....then bump it up one degree at a time...don't go over 35...

watch your engine temps as others have said...don't go over 180 degrees

maxpower671 06-21-2011 08:26 AM


Originally Posted by fast75vega
sure your carb is jetted right for the alky? what temp you running? we were running mid 9.50's @ 160deg. ... jetted it down and got 180 temp and running 9.43's now

how many jets sizes did you move ? what carb, fuel system?

melson3086 06-21-2011 12:36 PM

I went from gas with 2 750's to alky with 2 850 ken Jones converted carbs A2000 pump boost ref regulator took the secondary jets from 79's to 85's both carbs figured better to start fat!


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