Dynoed car today... Air fuel all screwed up. Some advice?

[Stang8URMPRT]

Ok, so I got the Stang dynoed today. It's a 306, 10.5:1 with forged internals and stud girdle. Custom Crane Cam, Torker II 302 intake, full exhaust, MSD dist and 6A, and a 600 Edlebroken carb.... Also, a Cheater kit with the 150 jets installed with a dedicated fuel system for nitrous enrichment... enriching 110 octane. Total timing is +-30 degrees.

My car made 310 RWHP at 4000 RPMs, and didn't change all the way to redline. I made 400 ft/lbs of torque at 3500 and it wasn't steady. My dyno graph looks like a plateau! Here's the shiitter, My air fuel ratio was off the charts... So rich that it didn't read that rich. lol... It fell off well below 10:1 which is where the graph starts. No black smoke... I pulled out 1 psi from the nitrous which didn't pull it back up even to 10:1 but hurt torque 16 ft/lbs. My fuel pressure is 5.5 at the carb, and 5 psi now at the fuel solenoid for the nitrous... I think my culprit is the POS edlebrock carb I have. What do you guys think? Are these easy to rejet and what jets should I use?? Or would it be easier to just get a 650 speed demon?? Thanks for your help Stangers, and I will post a pic of the dyno print out shortly!

Nick

 

[Stang8URMPRT]

ttt... It's aggrevating me! lol.. Help out here carb guys.

Nick

 

[Stang8URMPRT]

Here is my dyno sheet...

View attachment 523851

 

[Stang8URMPRT]

ttt

 

[timewarped1972]

what do you have for cylinder heads???? and what are your cam specs? was that pull with out the n2o? you definatly have some carb issues.....

 

[Stang8URMPRT]

Completely stock E7s... Cam specs are .484 intake .512 ex... 212 @ .050 in, 226 @ .050 ex.

I figure I'd make 250 on motor and closer to 400 on spray. This was on SPRAY.

 

[timewarped1972]

well with that manifold, and the cam, those heads are'nt helping. that manifold and cam should be good to atleast 5500 ( the manifold to 6500 )but your heads wont be. as for the n20, and your carb, sounds like your carb and or the n20 is waaaaaaaay riching your engine. you might wanna try getting the engine running right without the n20 first. you have torque but your horse power is falling off fast. horse power and tq cross at 5250 rpms so if you can get your engine to run good up to there or 5500 you should be ok....those heads aren't helping but somethings dumpin fuel in there......

 

[Stang8URMPRT]

Well no **** those heads are helping anything, but they are NOT the culprit... Sure they don't make the power like Trick Flows would, but I ain't got 1500 bucks to dump. The cam is perfect for the stock heads, and the intake is a good intake for a nitrous plate kit. I pulled out .5 psi out of the nitrous enrichment on run 2, and .5 psi out on run 3, with no help, other then hurting torque. I've been told the carb is fuqed and I've been told that the timing is the problem... Dunno... But I know it's not the heads. The heads have nothing to do with the air fuel being that bad.

Nick

 

[timewarped1972]

no, but my point was, when you have a manifold of that type the heads will bottle neck it........and no thats not whats making it overly rich, but with that manifold and n20 is trying to cram alot into the stock heads. did you make any runs without the n2o? start with the carb and when thats fixed then mess with the n20. and yes heads are pricey but you can have the stockers ported for not alot and it would help with the combo you have..........just tryin to help.....

 

[maverick0716]

Sheesh man, don't freak out on people after you just begged for their help.....it doesn't look good. I bet you do have a carburetor problem for sure (or the n20 like the other guy said) instead of messing around with the Edelbrock, you should get a Holley or Demon 650 DP. You're right about the cam, it does suit the stock heads fairly well.....but that single plane intake may be hurting you.....but then again I'm not a nitrous guy so I have no idea what would or wouldn't work good with nitrous.

 

[Stang8URMPRT]

lol.. I wasn't biting his head off... Just being a smart ass. The single plane is better suited for a plate nitrous kit because it dispurses the nitrous more evenly... without the obstruction the dual plane gives... That's the reason for the single plane. I actually like the intake a lot, and sure I lost some low end, but it pulls like a bizotch at top end. I'm going to take it to be tuned by a local guy well known for his tuning capability... Just wondering if anyone has had this problem before.

Nick

 

[Stang8URMPRT]

Also, like I said I pulled fuel pressure out of the nitrous enrichment and it didn't help, just hurt torque.. But the air fuel never came up.. So it's def a carb or timing problem. I'm going to have the car dynoed on motor very soon and get it taken care of.. I was stupid for using all three runs on spray... With spray, you tune the motor for NA and get it running perfect... THen you introduce the nitrous and tune around it.

Nick

 

[green]

if your carb was bad, i think you would know it even when the car is idleing, if it was getting that much fuel it would never work right. id say its not the carb, but maybe timing. id try it on the dyno without the no2 first and then go from there.

 

[Stang8URMPRT]

if your carb was bad, i think you would know it even when the car is idleing, if it was getting that much fuel it would never work right. id say its not the carb, but maybe timing. id try it on the dyno without the no2 first and then go from there.

The car doesn't run "correctly" on motor either... It gives me a bad hesitation when the secondaries open up. You can tell it's running super rich at idle and it sorta bogs until about 3000 RPM at WOT, but not at part throttle.. It's crisp and pulls nice at part throttle, basically about 3/4 throttle right before the mechanical secondaries open.

Nick