boonesjgsilverado

iTrader: (2)

i have a 69 camaro with a lt4 tea stage 3 heads 12.1 comp 383 and so on its getting tuned and he says its falling on its face above 5000rpm he wants to put a msd 6 box in it to give a hotter spark is it worth the money and is it even the problem?


thanks guys

moehorsepower

iTrader: (3)

OK, It has heads, what cam, injectors, fuel system ect. it could be all of the above, tuning, or valve float, opti ect,

96capricemgr

iTrader: (1)

An MSD box is not going to fix this. Guys are making massive power to the pcm's rev capability with stock ignition.

Moe, has some goosd suggestions there, I like the valvefloat one in particular becuse there are a lot of guys putting undo faith in people who can not spec a proper valvetrain AND it seems that adjusting valves is something a lot of folks struggle with again causing valve float.

A lot of guys "upgrade" a lot of good parts by putting LESSER quality aftermarket stuff on too, look at the current thread about "when to upgrade MAF? for an example on that.

Maybe tell us what year pcm you are using with this too.

Jon@BruteSpeed

iTrader: (3)

Is the timing getting pulled out of it?? Do you have a fuel pressure guage on it? If this is on a dyno throw up the chart.

z28_theantirice

iTrader: (2)

Fuel pressure is a good place to start. On my LE2 setup on a stock block, it was running way lean above 5100 rpm. They didn't have a fuel pressure gauge when I was on the dyno so I couldnt confirm it. None the less if you are on a stock pump you are near your limits anyway.

boonesjgsilverado

iTrader: (2)

its a mighty sumo pump i think which was good to 800 hp i think. The pcm was out of a 1995 impala ss and the tuner put a maf out of a 2001 z06 i had a descreened stock maf and he didnt think that would work.
here is all the specs that i have on the engine i bought it from a guy on here 00TurboT/A
12:1 compression
Eagle h beam Rods
Eagle crank
Srp pistons
Tea stage 3 LT4 heads with port matched LT4 intake
Arp head studs
Arp main studs and rod bolts
comp 987 dual springs
titanium retainers
custom ground cam fro TEA 236/246 610intake
618exhaust 114LSA

Hardened pushrods
high volume oil pump
MSD opitspark
New GM waterpump
Polished fuel rails
polished valve covers
Holley 58MM throttle body
PCM with motor tune in it
total seal rings
4 bolt main
clevite bearings
0 decked
balnced and blue printed

and the car is setting at his shop so no dyno sheets. the fuel pressure was at 50 with the vac on it and it does have a gauge on it its an aeromotive fuel pressure reg. Hes says he has it runnin fat up top so i dont think its a fuel problem. but who knows

thanks for all the help guys

96capricemgr

iTrader: (1)

Don't know that it would surface that low but a LOT of guys who try and use those springs with aggressive cams find valvefloat issues, and that is a pretty aggressive cam.

Would probably look for fueling issues now and tackle the valvefloat once you are able to rev it.

You know the MSD opti is MUCH more troublesome than the stocker right???

If the tuning is poor then when the ZO6 MAF maxxes out at 360gps it may not be getting the extra fuel it needs.

Who is tuning it? The fact that he thinks a MSD box will fix this worries me.

You said it has a fuel pressure gauge and that you have it at 50psi vacuum on, that is quite high are you trying to make stock injectors work or something?? Is the pressure still holding while it lays over? What injectors are you using?

You bought a combo that had money thrown at it rather than knowledge and if you stick with it long enough you are going to get to learn a lot the hard way about how "supposed to be best" and actually best are two very different things.

If the "descreened stock MAF" was an f-body one it would have worked well, frankly with screen is better depending on the intake tract and it will read higher when combined with the LT1 pcm. The ZO6 MAF maxxes out the pcm's ability to understand it at 360gps where the stocker will read to 471gps. The b-body MAF would have been a pretty bad choke on a motor like this so I would not have used that if it is what you had.

boonesjgsilverado

iTrader: (2)

they guy i bought it from says it had 30 lb injectors. Force fed performance is tuning it. im just starting to see that the msd opti are troublesome do you think that is a possible issue? The tuner said with the angles in the intake ducting that with the descreened maf it would have caused some of the intake air to be read twice. As far as it holding fuel pressure when it lays over im not sure the car is 3 hours from me i will ask him to look into that.

thanks

boonesjgsilverado

iTrader: (2)

any more help on this?

jimbob

iTrader: (4)

I can tell you from experience you have to have a real good grasp on tunning when that Maf maxes out. I run a little more in the PE table where my 85mm maxes out the freq (usually 6k rpm on my car) and add a few more in the PE table around that point. Sense it does max out, I tune WOT at a cool temp outside to guarantee that I have enough fuel at higher rpms. It won't even be an issue when it gets hotter outside, except a little more richness.

boonesjgsilverado

iTrader: (2)

any more insight on this?

boonesjgsilverado

iTrader: (2)

would a ltcc setup solve some of my problems? would it be money well spent?

96capricemgr

iTrader: (1)

Probably not, the opti is vastly better than given credit for and the LTCC keeps half the opti anyway.

I might be inclined to try a stock opti instead of the MSD one though.

boonesjgsilverado

iTrader: (2)

do you think thats the best place to start were replacing the wires and coil first then we will try the opti, fuel pressure is in check and i need to check the valves. do you think i could be maxing out the maf? the tuner should be able to tell correct?
are 30lb injectors to small for this setup?

96capricemgr

iTrader: (1)

I know a guy with an Impala putting 480rwhp down through the automatic running 30lbs SVOs at stock LT1 pressure which makes them closer to 32lbs and the pressure you are running has them acting even bigger. The SVOs are rated at 39psi so at the pressure you run they are going to be over 35lbs.

The tuner should plainly see the maxxed out MAF the AFGS will stop rising and stay pretty steady, honestly this seems like a little too low an rpm to be doing that though.

boonesjgsilverado

iTrader: (2)

thanks for all your help