First off I'll give some details of my build.
355 11.7 to 1
Compstar 6" Rods
Mahle Pistons
LE Ported 21 Degree TrickFlow Heads
LE Custom CAM
LE Ported Intake
PP 58mm Throttle Body
Comp Ultra Rockers
42# Bosch III
ARH 1 3/4 Stepped to 1 7/8 Headers 3" X-Pipe
Performabuilt Level II
Performabuilt 3500 stall
Pcm for Less Tune

Thats the basics of the build and so far I am very happy with the way it has gone. It has amazing throttle response and drives really well. I had to drill a by pass hole in the throttlebody to get the IAC counts to about 38 to get it to idle. But now my next problem is when I get on it it seems to studder at about 4500 on up. It still has enough power to break the tires loose at 30 but then it starts breaking up. Every thing is new on it except the opti but I wasn't having any problems with it when i removed it plus I have the Delteq on there with it. When it dries up I'll try to get a run down the road with the scanner and see if it shows anything but I might be able to tell better when i get the mufflers on it this weekend and it quiets down but for now its got me a little stumped. I have a crappy phone video of idle I'll put up.

Things I'll check: (Before I change the opti and I'm open to Ideas)
Fuel pressureat WOT
Plug gap and new Plugs
Valve lash
Wires

http://youtu.be/bXDmTRicRXM

 

You've got some big injectors for your build. Monitor the afr to see if your motor is running too rich. Normally 42# injectors are used with much bigger cubes. What is your fuel pressure?

 

I have an adjustable fuel regulator set at 43.5.

 

Interesting. Why such a large tube primary?

 

Built the motor to out rev the factory computer so we wanted the bigger primary. So far it hasen't semmed to hurt it down low. Find out when we get it on the dyno and track.

 

Check your AFR with a wide band sensor, make sure it is not supper lean or rich. Also check your spark plug gaps and set then at .030 or less. High compression engines with high cylinder pressures require more energy to fire the plugs. As RPM goes up coil energy drops and at 4500 RPM you are probably near your your max torque or highest cylinder pressure which requires the most spark energy. Stock or near stock ignition systems are pushed to the limit with high powered high reving engines.

 

Breaking up is classic for a bad plug. Looks like a nice build! I should really up the compression on mine. I have a 355 also and with e85 run 46# injectors. Never thought I would have injectors that large on this car! It is working well.

 

Some guys put 32lb injs in their 383 build... according to FIC calculator for proper size injectors 42 lb are for 550 hp power band application ...what the hell of 355 ...better rich than lean

 

I ran 30# injectors on my 383 running low 11s. My 406 has 36# injectors, runs 10.50s and shifts at 6600. Monitor afr on all runs and the injectors are perfect for my application.

 

I gave the fuel injector place all the motor specs and they came up with these injectors. LE said this motor would be around 550.I hope they are not too big and can be tuned correctly. I have been thinking about putting on an O2 system to constantly monitor afr. Anyone have a part # for a good one they're using? The plugs are Ngk's and I dont think we even checked them before we put them in because we were excited to get it running that night. My other concern is we set the LS7 lifters too tight.(3/4 turn past 0 lash.)

 

550 on a HR cammed 350?
Like to see some specs on this one.
Head size (final cc), cam induction etc?
Flowsheet on heads?

 

I've used an Innovate LM-1 for years to monitor my afr. It has been invaluable. I have a speed density Accel Gen 6 management system and need to know the afr at all rpms in order to tune. I couldn't live without the thing. I think they are up to LM-3 by now. Well worth the 2 or 3 hundred. Willie

 

Cam is 23X @ .050 intake 24X @.050 exhaust. Lift is over .600 on intake and exhaust. They flow about 295 on the intake and 220exhaust. Intake runners are around 205. I don't really care about HP numbers well just have to see how it performs at the track. But so far I'm happy but I'll be happier when It has all the bugs worked out.

Thanks for the info on the afr I'll check into them tonite.

 

Not going to hit 550 but should be a solid 11 sec ride nonetheless which is pretty good no matter how you slice it. .

 

I'm running a 230/240 cam also with over .600 lift intake and exhaust with 12.5 compression in a 406. I agree with Cuisinart you should be well into the 11's with a pretty nice lope.

 

That shouldn't be an issue.

 

I agree with the poster in regard to the spark plug gap. I would also look at the Delteq-I use to run one and when it did not work it did some funky stuff.

It sounds nice in clip!

Steve

 

what timming chain you gona use??? dont get the cloyes the cam gear will eat the teeth of it...ive heard u can use the lt4 extreme unit with no problems but i havent used one yet...

 

I used a factory new gm cam gear with a cloyes oversized crank gear and a cloyes chain. The chain was very tight and my cam timing was right on.

 

If you haven't already you may want to datalog your motor and send the computer back to PCMforless to have it fine tuned. It can take several tunes to get it good and they don't charge for the second tune it's free. There first tune is close enough to get you running and on the road but you have to do a datalog to get it nice and crisp. You can download Datamaster program for free and get like 20 downloads from it. All you need is laptop and your ADL cables It made a big diffrence on my 383