954RR

iTrader: (1)

Went to the dyno last night and am a little dissapointed in my numbers. (See attatchment). Car made a max of 358/ 349 hp/tq. Mods are in the sig below. We were tuning with HP tuners.

The heads are bone stock except for some 918 springs, on stock block. For some reason the car did not like anything over 19 deg of timing. We tried 21 and got knock and the air fuel was around 13-1 (Not sure if it can be read clearly from the graph) I am running BP 92 in the tank as well.


It was around 70 deg F in the dynoshop and we had a big fan blowing in front of my car so I don't think that was the problem. ELE is 1100 ft. This was a dynojet as well.

When we were done he showed me countless other dynos where cars with cams like mine without things like LS6 intakes were making the same power as me. Some were cam only cars and there were making more power. Hell even a stock graph was comparable to mine.

I know heads would help but why does this thing dyno so low in the first place?

Any advice, comments? TIA

ls1wannabe

iTrader: (2)

maybe you need some more tuning and a pulley wouldn't hurt either

Pete K

Silly queston...what did your car make before the mods?

Also, seems like you were getting detonation after 4500 rpms.

Pete

2xLS1

iTrader: (25)

19* of timing is what killed your power.

BlueSix

I'd say you need to figure out how to get 8*-9* more timing to make optimal power.

954RR

iTrader: (1)

Thanks guys for the replies!

Not sure what the deal is with timing, I just know that it would pull timing with anything more than 19*. Pisses me off!

I purchased the car from a member here and he had the tuning done at straightline performance back in may of this year after all the current mods. Back then it would only take 19* as well but on their dyno it made 20 hp/tq accross the graph more (ELE there was 500ft mine is 1200ft) than it does on mine and that one was a mustang... this one is a dynojet.

At 19* WOT it pulls NO timing whatsoever. We pulled in 5 times. Not sure what it made before the mods because I bought it modded.

As far as ignition goes it has NGK tr55 plugs and MSD wires.

I am going to run a leakdown test on it this weekend to check the bottom end but that wouldn't cause it not to be able to have less timing?

954RR

iTrader: (1)

any other insight?

I am now looking into some other cam options

lilbuddy1587

iTrader: (1)

Without optimum timing, a bigger cam or any other cam will still not make the power you're looking for. You need to address the small problem first and then dive into another cam swap if need be.

954RR

iTrader: (1)

Should I put this into internal engine??

True... still not exactly sure what to look for as far as getting more timing.

the cam has 4deg of advance ground into it as well, not sure if it makes a diff.

even if i did a compression test and found less than normal wouldn't that allow me to run more timing due to less static compression?

i am positive this is not false knock as well

any suggestions on what to check look for?
TIA

Bombguy99z28

What was your injector duty cycle at? Did you try backing off your A/F ratio a bit? I'd push it back down to 12.8 and see how it does. Is 13.1 what you are commanding? (using the PE table). Check your fuel pressure at load, maybe its dropping when you hit the throttle, causing you to run lean and have to back the timing off. When is the last time you changed the fuel filter?

Something is wrong with your tune somewhere. I am just about at 12:1 compression and I run 21-22 degrees of timing. Not saying you should run max timing, just whatever timing is good for your heads. Which being stock should be around 26-27*

954RR

iTrader: (1)

I asked my tuning guy and he said injector duty cycle was fine AF was actually 12.8 which was what we commanded. We logged fuel pressure just in case the wideband wasn't accurate and it showed 56 or so all the way through.

As soon as midterms are over (this weekend) I am going to pull the plugs and check them. Then do a leakdown test.

Fri afternoon we are going to put it back on the dyno with race gas and see if there is a possibility of false knock making it show KR when it might not be. If so desensitize them some.

This look like a good plan of attack? What about the MSD wires, should I put the stockers on?

300bhp/ton

Pointless.

It's not the cam at fault, and this spec cam has proven to produce GOOD results.

You have an issue with your car, and by the sound of it, it was an issue before the cam swap. I know it's a bit late in the day, but you should have spent the money fixing the car not buying a camshaft. As now you have more issues to deal with.

This is always a risk with modding a car, even more so if you by a car which is already modded. You just don't know what's been done to it, you only know what you find or where told.

You really need to get some one to look at the motor and find out what's up with it. Solve this and you should make reasonable power, if it's still not enough, then it's just a bad cam choice on your behalf.

SideStep

Question is why... I get away with 27-28 degrees timing, even in the summer.

-Oil Vapor in the cylinder
-Damaged piston or head/chamber facing the piston
-???

954RR

iTrader: (1)

How could it be a bad choice of cam on my behalf? I bought the car modded.... meaning cam/ headers/ intake and other misc items were already installed.

I have bought no camshafts. My thought on ME researching other cams was maybe the cam was degreed wrong or something is wrong with it in general. I am trying to find out what timing the car ran before the cam swap. If it was higher like say 27 or so them it will lead me to believe cam is causing it or maybe knock sensor messed up.