After a long winters nap. We took the Mad Maverick up to the chassis dyno to lay down some baseline numbers before upgrading (hopefully an upgrade) to gt40 heads. I can say i was quite pleased with the results. I had hoped and was going to be excited for numbers over 250 hp. While getting trans and rearend oils up to temp with just a small road load numbers climbed over 265 hp . After the second pull, clutch parts started appearing from under the car, oops thought there was a problem at the end of last season... sho nuff. After the 5th pull the clutch was done! The o2 sensors read rich the whole time, got them leaned to 11.7 - 12.5. Good turbo numbers but i dare go no leaner. I looked around on the net for numbers to compare not much available, everybody has aftermarket heads and intake and 4bbls. Oh yeah for the final results 314hp @ 4500 and 323 ft lbs @ 4000. Headed to the track Saturday night, after a quick clutch r&r.
314WHP is VERY good for GT40 heads, 330 is the most I've ever seen with those. The average is around 250-280WHP http://forums.corral.net/forums/5-0-5-8-engine-tech/1270602-post-your-gt40-setups-here.html
He was referring to the A/F numbers, at least that's what I'm thinking... I don't think circle track cars are allowed forced induction or even 4 barrel carbs.
Wait a minute I don't think he even has GT40 heads on, I reread his post and he says he's going to upgrade them to GT40s.
Ya it does say that. Then it says he way tryin to compare his numbers but everyone has aftermarket parts and 4 barrels. So that means the engine is bone stock? And puttin up those numbers? Interesting
On this thread it lists him running a 351, which makes the numbers way more clearer now http://mmb.maverick.to/showpost.php?p=706262&postcount=19
351... yes a 351, 69 windsor heads, cast iron 4 bbl intake, solid lifter hydraulic cam, roller rockers, headers, stock crank n rods, badger flattop pistons, holley 4412 2bbl w adaptor... I just got the new valves for the gt40 heads and am gonna send them off for prep, hoping for more whp! Im still figuring im down 40 hp to the well prepped bowties. sorry dont have video on the dyno, the only one i have is a phone video of it running away from those pesky bowties....
You could get a bit more power out of your current setup if you would lean it out some 12.8-13.2 is what you should be shooting for n/a and be safe 11's are pig rich n/a dont give up the free power you have. I wouldnt pull the old heads for the gt40's jmo
mixture I melted one motor figuring i had mixture at optimum, I beleive the stock intake is missing the mark in some cylinders. I currently have mixture numbers that are a whole point differnt left to right side. The possibilty of one lean cylinder is making me keep it on the rich side as i dont have headers with probes for each cylinder. I have thought of going to a 2bbl intake which would seperate right from left and give me a way to lean one side more than the other. Wonderful problems rules introduce, an aftermarket intake would be a good fix if rules allowed. As far as the gt40 heads i like the look of the exhaust ports, not as squenched as the 69 windsor heads. Of course i cant find any flow numbers on the stock heads. Chamber size really isnt an issue as both heads seem to have alot of room for milling.
I built paved limited late model stock cars for 24 years and the track required us to use a 2101 Edelbrock intake (sm bk Chevy) with a 4412 Holley 2 barrel. Very easy to tech.
