Had heads cut to 64cc , used 40 th. comectic gasket , did cut right much out of valve relief of -12cc mahle pistons but they come 5 thousands out of hole. Should still be at least 10.5 comp. at minamal I would think

 

Injectors you want to run at 80% duty cycle. That was one of the things that I noticed. The injectors MAY be too small. An unlocked converter will also put out lower numbers, especially if its a "loose" converter. I believe a VIG3400 is more like a 4000 since they're advertised lower than they are last time I read.

 

Does seam like convertor is REALLY loose in car. Thinking about sending it back and getting it tightened up some after I run it saturday.

 

If you're looking for better track results, then a looser converter will net you better times. Now if you plan on spraying it, then a tighter converter will better suit nitrous. You have to decide what you want, a naturally aspirated setup or nitrous.

 

Want a tight convertor because I want to drive the car alot on street and spray it for the track. Very good point you made.

 

Are you using the stock fuel pump? If you are, then this needs to be replaced before you touch the injectors.

 

First off, get the stock maf out of the intake track, replace it with a piece of tubing and tune SD. Ditch the Mac mids and get full 1-7/8" headers. A ton of your power will come back with these two mods.

Listening to the symptoms, the torque peaks really high for only 405 lb/ft. If it's unlocked you should have a huge torque spike at the beginning of the run of 500+ rwtq. That converter will still be fine for spray though even if it is flashing around 4k. You might be blowing through the converter though.

Also, you shouldn't be close to making out those injectors with only 415 rwhp. Do you still have a stock fuel pump? What fuel pressure are you running? Stock fuel filter still?

Something just doesn't add up here and I hope you can get to the bottom of it with the help of this board.

 

Who takes their car to get dynoed on a new combination like this and leaves without getting it printed to look at? Especially if you think something isn't right. And doesn't know the a/f ratio. Then seems to not know much about the motor and setup. Something doesn't add up.

 

You're running the same size chambers as me and the same HG and the same out of hole. My compression ratio is right at 12:1 w/ 2cc pistons. Not sure what another 10cc of dish does to the SCR. I'm also running a lot higher DCR than the G5x4 will give you.

Something is not right though. Good luck. Get that thing tuned again.

 

I know nothing about tuning cars, but nobody has yet to ask who tuned it.

 

With a 12cc dish it puts him right at 11:1, but that X4 is killing his DCR.

Nate

 

Oil = Knock ?

 

I found that exhaust makes a HUGE difference with these big displacement motors. They simply need more to breath because the move so much air. You can free up as much as 30 hp or more just by having the correct exhaust setup.

Then I would take a hard look at your tune. AF ratio and timing advance. If your running too rich for some reason that can absolutely kill power. Find out if the tuner suppressed any codes and find out what the codes were. You might even be getting some KR.

I would try those two things before buying a bunch of new parts.

So, if you take your baseline, 415, add 30hp for better exhaust, add another 30 for a proper tune, that puts you at about 475 hp. Just about right for that motor with those heads going through an automatic.

 

Yes still have stock fuel pump and filter. What is tune SD mean?

 

Speed Density... aka MAF-less.....

 

What's DCR and SCR? I apologize for my lack of knowledge on abbreviations.

 

Speed density.

 

Dynamic Compression Ratio and Static Compression Ratio

 

Probably a person who just got into this ls1 stuff for the first time, thats why I paid people to do this stuff for me. What good is knowing the a/f ratio if I dont know what it means, you think? Thats why im asking for help not sarcasum please.

 

Air / Fuel Ratio (your tuner should be able to tell you what your A/F ratio was when he tuned it). If he can't, I would take it somewhere else to get it tuned.