|03-25-2013 07:36 AM|
Cool! You're on the right track... (:-
|03-25-2013 07:17 AM|
|03-24-2013 12:42 PM|
|menoaz||Update.. last night ran a 10.94@126mph. I kept the 5lbs boost and changed the. Shift point from 6200 to 6000 and changed the overall timing from 28 to 33 with the BTM. THXS again everyone. Cloud 9|
|03-19-2013 07:46 PM|
Thxs jim for the advise
I will try short shifting it next time. And me shifting at 6k was cause everyone here would tell me that my 8-71 would start making to much heat above that and wouldnt make power after that 6000rpm. Yes the cam in wrong and in the off season it will come out. Due to sequestration and 40% pay cut it will be awhile before i go back. Thxs again jim
US BORDER PATROL
|03-19-2013 04:52 PM|
I'm a late arrival in this thread. I usually stay away from "blower" stuff... Too many opinions. Very few pros. It's obvious here, who's who on this site for blowers! My compliments and my thanks. I learn from Jester and Cobalt every time I read something they write. Everyone else, of course. I just had to point that pair out. Good stuff!
I have input. First an observation then a question. Your gear is still too "low" (higher numerical). BBCs with small blowers (what's your ratio?) make torque like big N/A Pontiacs. RIGHT NOW! Take advantage of the massive low-end and gear it "up". We use 3.90s for 461s in cars under 3,500 lbs. and 1/4 mile. That MIGHT be a little stretch, but 4.10s are certainly correct. With a little shorter tire, the "top-end charge" with 3.90s will significantly improve MPH, and usually a corresponding improvement in ET. The idea with a "torque" motor is to "short-shift 1-2 and maybe a little 2-3, but "let 'er eat" in 3rd. Which leads to my question...
Why are you limiting the RPM of a short-stroke BBC to 6,000? 427s are "safe" at 7,000 when you upgrade the rockers and distributor, with stock "everything else". With the small amount of boost you have, good forged pistons and good factory rods are "up to the task".
A nitrous cam is WRONG WRONG WRONG for a blower engine. Sorry, but it's true. You're pumping mixture out the headers... Too much overlap. Nitrous engines "like" it for the scavenging effect. They also generally have longer duration on the exhaust side than "blower" cams. IMO, with a Roots-style blower, you really should have a blower-specific camshaft. You can "adjust" the duration and lobe centers to suit your RPM requirements. We use Comp exclusively for this. They have good engineers. The valve train is the LAST place to "scrimp" when building a BBC. You need the good stuff.
|03-19-2013 03:32 PM|
|03-19-2013 01:08 PM|
|AutoGear||AWESOME and thanks for posting that!|
|03-19-2013 08:33 AM|
|menoaz||Heres an update on the hot rod... I finally got the car really close to what i wanted at the track. I ran a 11.12@125mph. With a 1.60 sixty foot. Now this is all i changed and i got the 6200 thru the traps that i wanted in 1/4 mile. I really wanted 10's with only 5lbs of boost. Got really close. Hughes worked on my converter to my specs with my old 9" for 450.00. Swapped my 4.88 to 4.30 ratio and got my Holleys boost referenced at Larrys Marine in Tucson for 150.00. Thxs everyone for all the info hope this helps someone else later.|
|12-19-2012 11:29 AM|
I think we would all like to see that! Its good when we can all help!!
|12-17-2012 04:53 PM|
|menoaz||Thank you for the reply, i got some 4.11 gears,I am changing converters Hughes give me a great price at 450 to fix mine. If I am losing torque imagin with all the torque my wheels are going to be coming off the ground really easy. If they all ready do abot 6" at part throttle.|
|12-17-2012 12:29 PM|
I posted this on the wrong thread the other day LOL It was meant for this thread (better late then never)!! LOL
Here it isPositive-displacement or "Roots-type" superchargers tend to produce massive power at low rpm and taper off higher in the rpm range; from Idle to about 5500 Rpm on a low boost engine which is usually on the street or a weekend warrior!
You converter and cam don't come in till late and are wasting all your torque your putting out at your lower RPMs with a roots supercharger. Right off idle an engine with a Roots supercharger will typically have nearly full boost and massive power. This power increase will be fairly constant throughout the RPM range. Till it reaches an rpm point that the supercharger begins to lose efficiency!
Turbos are the other way around! low boost at idle and as rpm comes up boost increases to high rpm so you need high stall speeds and cam's that come in late!
Sorry its late LOL Jester
|12-12-2012 09:07 PM|
You need more crank case ventilation , especially with boosted engines!!! You need fresh air entering and boost pressure and contaminant's leaving the crank case. At the least a PCV and if your boost goes up you need more A header collector type evacuation or a pump type!!!! Boosted engines need it or your damaging internals, and losing horse power.
|12-12-2012 07:27 PM|
|menoaz||Just the air breathers.|
|12-12-2012 04:41 PM|
If that's the picture what kind of crank case ventilation do you have?
|12-12-2012 03:23 PM|
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