does this make sence

[melson3086]

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]

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

[maxpower671]

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]

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]

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]

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]

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]

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]

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]

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!

[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?

its a 850 holly that flows like 930cfm's it had 146's x 4 and went down to 142's x 4 and it ran much better. we just pulled it apart and put 140's in it and we will see this weekend :wink:

[maxpower671]

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!

correct, better to start fat and move slowly...but still make a real change to see if it helps :wink:

i wonder if that is fat though???? Does Mr. Jones have any advice?

[maxpower671]

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?

its a 850 holly that flows like 930cfm's it had 146's x 4 and went down to 142's x 4 and it ran much better. we just pulled it apart and put 140's in it and we will see this weekend :wink:

looks like you're moving in the right direction....watch temps and MPH, and have fun 8)

[fast75vega]

looks like you're moving in the right direction....watch temps and MPH, and have fun 8)

yeah.... its getting there.....it ran 9.43 @ 144.67 mph and was 180 deg when he got back to the pits. its a 1/4 mile track with 3000 feet of shut down plus a long as return road and it still was only 180 after all that.... so we jetted it down to 140's square :wink: