I scheduled some time at Dynolab in Marietta, GA on Friday and got 242 hp and 283 ft/lbs at the wheels! I'm pretty happy with that. We tweaked the carb a good bit, got 6 pulls I think and went from 235 to 242 just by switching out jets and seats in my edelbrock. I ran out of time but I have an idea of where to go from here so I might be able to squeeze 5 more out, its still running a little lean at WOT (I've got an O2 sensor bung welded in my header for checking A/F). I need to scan the sheet; I'll post it when I get home.
Stock shortblock GT-40 heads 1.6 Roller rockers Weiand Stealth intake Edelbrock 600cfm Mallory Unilite distributor (I've got a Hylite IV that's not hooked up yet) Comp Xtreme Energy cam 218/224 lift .493/.500 Timing is at 13 BTC Hooker long tube headers 2 1/2" duals with x-pipe and flowmaster delta flows Electric Fan Aluminum radiator T-5 Pro 5.0 shifter open diff w/ 3.55 rear gears When I get bored I'm going to port the heads and gasket match the intake and step up to the next bigger cam a 224/230 .509/.512
you can lighten the weights on the secondarys. you need to take the lid off then you can lift the secondarys thingy (dont know the correct name for it but it covers the bosters and pulls open when intake vaccume gets high enough when floored). on the thing there are some weights on each end of it. you can lighten it by drilling holes or grind on it. this will allow it to open with less vaccume giving it more fuel on the top end. or you can get a holley.
I stepped down the metering rods as small as they would go, then since that wasn't enough we put the next smaller seats (I guess that's what they're called) and went back up to a bigger rod. This gave about the same A/F as the smallest rod on the stock seats. I ran out of dyno time but I've got a pretty good idea of what the next step down in rod size is. I should be able to richen it up by switching that out. Really though around town 5 hp on 240 prob won't be that noticeable, IMO.
Glad to help, save someone the $200 and 2 hrs of dyno time. Even though it seems steep I had 2 hours with time to tune between runs for a total of 6 runs. I couldn't find anyone else w/ a better price...
maybe a...600 CFM vac. 2nd Holley... i have a little more motor than he does and a ...Double Pumper... was too much...JMO ain't it a blast when they turn it up.......i saw 128 MPH last Sat. when i went... i'm going back Sat.for a couple of more pulls...(i'm working on something) ......
Where did you go, Covington? I was around 110mph at redline in 4th (1:1) What's your gearing? And as for the carb, its all theory b/c I don't plan to change the carb any time soon. I think this one is fine, I just have to richen it up. There's plenty of carb left, I still have a lot of sizes to step up the fuel mix. Like I said before, I'm not sure how much I could tell 5 hp anyway. (psst...whatcha workin on?)
These guys are accross the parking lot from me at the shop and have said they would be willing to do my dyno(s). The sound of motors revving up to those rpm's is crazy. Makes me feel like I need to hurry! http://www.rx7.com/racing.html
Good to see you tune on the dyno, thats one of the best ways, as every ones combonation is different,even with two cars built the same way. the drag strip is also a real good place to tune (if you dont mind the time it takes ,its alot cheaper than the dyno). I didn't realize how much info you could gain by the dyno , (but even if it points you in the right direction its worth it.) until I put my 07 mustang gt on one, (it had a C&L cold air intake,ford racing X pipe,flowmaster mufflers,( and on the dyno loaded up a sct excal 2, tune in )and made a first pull... well sct is in florida??? I think?? and their tune was a little lean when we looked at the a/f ratio , not enough to hurt anything mechanical but not rich enough to make full power from the tune, well in florida they run straight gasoline and where im at in illinois we have 10% ethanol added to our gasoline and thats what made their tune a little lean...so after 2 more pulls we added 6% more fuel through the whole rpm curve to get the a/f ratio right ,left the timing curve the way they had it, increased the "tip in" and raised the rpm limiter by 200 rpm,turned the traction control off and(loved the sct tuner) made 282hp at the wheels , drove it daily for 28,000 miles and raced it at the track quite a few times and never had a problem.... from then on I like the dyno and think its worth the effort of time and money.. hope when I get the new engine done for the maverick I can have a nother good time on the dyno...this time with a carb and E85.!!! best of luck to every one and have fun with your projects.