i am using a PCMforless tune, stock ignition setup, and s-trim hitting ~5psi @ 5700. I just recently dynoed the car, and made 310/319 and bottomed out the wideband at <10:1 AF for the ENTIRE run. also the car is a 93, so cant use an LT4 KM.

i am seeing ALOT of knock counts, for example, a little 1/4 run netted me 3400+ counts. the spark advance is about 26 degrees, but goes as low as 21 with a degree of spark retard.

i know there is alot of power left just in the AF alone, im guesing maybe 40-60rwhp? but my Q is what sort of timing should i be at? and is false knock common on a s/c'd LT1? I think my car is way off par from people i have talked to with close to stock, and stock LT1's with either a p600b, or s-trim, as they were doing low 12's and high 11's and i think im going to have a rough time even squeezing into the 12's.

 

Hmm, not sure why you'd have that much knock (what kind of rockers are you using?), and yes you should be making a hell of a lot more power. Get it dyno-tuned. On supercharged cars its pretty hard for pcmforless to get it right first try, just too many variables between cars.

 

I would agree on the dyno tuning, or logging data runs and either sending them to PCMForless to be looked at/tweaked as needed, or to tweak yourself if you have the capabilities. This is tough in your situation, as you are SD, so flashing the PCM is not an option. Your best bet is a dyno tune with someone familliar with FI applications, and burning capabilities.

Bryan can only take in so many things when tuning remotely, and WILL error on the side of safety to keep your engine in one piece

FWIW, I ran a Powerdyne 6psi before my previous set-up, with Bry's tuning. I never dynoed, but was able to send log runs to him, and make tweaks myself where I felt comfortable. I was VERY conservative on my tune, and still ran 12.4's @ 114 pretty consistently on a stock bottom end with no harm ( note, I am toting nearly 1000lbs more than the average F-Body as I drive a boat !!) And she is a daily driver

Please take a couple of things into consideration here, stay CONSERVATIVE on your tuning. With a stock bottom end, you will not be able to eek out the last "nth" or mph out of it without breaking something ( even if you are conservative...you still may break !!) Most importantly, if it isn't "right" or "feel" right, don't push it, or you will end up with a hand full of souviniers that used to be part of your working engine

Also, upgrade the igniton, and be sure to get something with a rev limiter. 1- so that you make sure that you can provide adequate spark for the increased cylinder pressures, and 2- you take the fuel cut-out out of the equasion. Also, you did not say if you upgraded the spark plugs. You really need to run a copper plug (no platinums), in a colder range. The NGK TR 6's work well for me

 

I've actually been working with Alvin through this and i have been sending TTS reports back to him and were on about the 8th or 9th revision. I considered modifying his tune a little bit aswell, just lower the spark advance to maybe 19 degrees in the extended RPM range to be safe and also get my buddy who has a wideband to come monitor for me. I think the tranny is a big problem with it aswell, as it is no where near good shape (very ****ty rebuild from a "reputable" shop who held the car for months just to get out of warranty work) when the car was stock, and i had the tranny built i went from 9.4's to 9.0s in the 1/8 and would just smoke 2nd gear every time...now if i can spin them top of 1st, i feel i have accomplished a great feet

spark plugs are NGK TR6's and gapped to ~.036. and 8.5mm accell wires.

the way i calculated my times out right now, with a 2.0 60' i think i would be running 12.9-13.1 @ ~108mph (best 1/8 was 8.5@84.3)

also, the car is ENTIRELY stock besides the blower. not even LCA's.

 

Im a local tunner....

Imagine this:

I have tuned 3 s/c cars.. and in each it has taken me more than 10 reflashes... A LOT MORE THAN 10 to get them right..

why?

because it wasn't me who put the setup.

TR6 are probably too hot for 5psi... tr55 are normal plugs... so I recommend a 7.

All plays a role... bad installation can make the tunner go nuts.. and with a supercharged car there are many things to take into account...

Right now i am tunning a 10psi stock CR car.. and its been a bit difficult...

 

but what about the installation could i have fubared? everything fit perfectly, i followed the directions to a T. only thing i had to improvise was the intake piping leading to the vortech, as i bought the kit used.

 

Do you even have headers? You can pickup 30-40rwhp woith a good set of LT's.

 

I have seen on my car too much fuel will cause knock IMO 11.5 would be safe. I have an ATI p600b w/2core intercooler on my old set up I seen 7.5 lbs boost and I used NGK TR6 gapped at 0.035”. The W/B that you using how low of a reading will it go if you bottomed it out maybe it was even lowwer. I tuned in 24 deg of advance at max boost.

Kris

 

Its sometimes what you chose for parts...

different things... it takes a while.. all im saying is be patient.

 

the WB i was using would only read as rich as 10:1.... i need to lean it out a bunch because im probably going to kill the motor from being too rich. i made another .bin file to burn, didnt mess with the fuel as i dont know what to do with that, but i brought the timing down alot. about 19* spark advance at 5600..i havent burned it yet to test it though.

as for headers, no, i dont have them. i am not buying anything for the car performance wise besides a bottom end and tranny until i know it is tuned in...if i start adding more stuff without knowing where i am at now, its just going to end up hurting me later.

just curious as to why being very rich would cause knock? i have never heard anything like that before.

 

If you add the headers.. you start from 0 again..

 

Not sure why it caused knock but it did, somone tried to explain it to me once but I forget. Seen alot of knock at 10.0:1 (might have been richer) and at 11:1 only when it went in PE mode approx. 300 counts.

Kris

 

ill have to get my friends wideband next chance i get. if being rich does cause knock, that is most likely where it is all coming from. its just wierd that it isnt audible to me or anyone else that i have taken for a quick ride.

 

If your tranny is shot, as you mentioned earlier, your dyno readings will be off. Your not putting the power to the ground, and there is probably less load on the motor therefore not requiring as much fuel. If you lean it out with the tranny shot and you get it fixed it probably will be off again. Get the tranny working properly and start from there.

BTW when adding fuel or removing it at WOT use the PE table (LT1 edit) or the %enrichment per RPM table (Tunercat)

 

Running rich can cause knock, I'll second that and no I can't explain it either.