Schurters LT1

OK is there a diff from dyno to dyno on rpm?

Am i over thinking this i make peak power at 6600rpm , ok parts

Ai heads(fixed ARE)
gm 847 cam
1.6rr
1 3/4 mid headers
52mmtb
all the outher bolt on's

going to next year
58mmtb
LT headers

There is outher people on the board that are making power @6900rpm, is there somthing in my set up do i need to change somthing here or is that just all there is?

HELP!!!!

Ai

Jeremy,

I think peak power at ~6600 is about what I'd expect with that particular setup... so thats normal. If it doesn't fall off too badly, then I'd probably shift around 6900...

Mmm, I need to try to find that program to convert my files to something you can use to experiment I suppose. I'd grab freescan & log it though.. somethin's up .

Schurters LT1

HM ? Ok , no the power comes down slow after 6600rpm, Phil you have see the other cars on here that are posting high revs them me with the same set up, should this be a problem , or just drive it ,

I went back to the dyno and had spraytheway do the tune on the car cleaned it all up drives nice, still the same power number 380 but i am making 380from 6200 - 6600rpm tq is up 10ftlbs, i can maybe lean this thing out a little more and try a little more timing but that is it i think o well we will see when we go to the track and put up some numbers

rskrause

What valve springs?

Rich Krause

Heatmaker

Why do want to go over 7K RPMS's? I thought that was bad for these cars?

STAR

What's your exhaust set up? If your exhaust is choked up, than no way can it make any more power up top. The hp seems a tad low, but the tq is really low
AI heads produce some great numbers, I'm sure there's some more power lurking in your combo. BTW, can you give some input about the your heads before AI fixed them? HP or flow numbers? Phil, feel free to comment
I agree that your peak hp should be about 6600 rpms, but if your headers can't scavange the exhaust gases then that's your bottle neck!

Schurters LT1

V spring are cc 918 set up by Ai, Um the tq is 351 @5400rpm i think i will have to ck. HP is @ 381 @ 6600rpm the , Would the twin disk have anthing to do with this being that the flywheel is 60lbs?

With the ARE heads and cc306 i made 350hp 330tq

got_hp?

?

STAR

What kind of headers? Is he running cats? What diameter piping? Stuff like that!

atljar

Thats about where i would expect the peak too, but the numbers look very low IMO.

Ai

Part of the problem was the jacked up ARE ports I was trying to fix. Unfortunately, they were large where they should have been small & small where they should have been larger. The latter is an easy fix, the former would have required welding.

They peaked at 273 IIRC, but the midlift #'s werent what I'd like to see due to a couple areas that were already way too big. Not much that can be done about that... a good example of why it's always best to start fresh though .

I think it should still make 395-400ish through exhaust & around 370rwtq, but ahh dunno, could be tuning, could be a few things. Springs are probably 985's, not 918's, but I'd have to go check paperwork to figure that out. Dunno, could be all there is in it I suppose, but I'd tend to doubt it. Not much you can do but tweak/tune on the dyno.

Schurters LT1

Ya sorry worng spring 987 yes i know i sould have started with a fresh set of heads o well, Phil did a very good job of geting the number up on the heads he did his best.

What kind of headers? Is he running cats? What diameter piping? Stuff like that!

Headers 1 3/4 rksport mid 2 1/2 " y pipe, 3" off road pipe, borla cat back,

Lets set HP/TQ number aside because well all no every dyno is diff know one would say anthing about my HP/TQ number if my car was going 1117-118mpr in a fully load T/A .

Where should i start looking ,change, do.
thx

Ai

Pick up Freescan, http://www.andywhittaker.com/ecu/ecu_software.htm

I'd start there . Send me the logs & I can poke through them & share them with a few guys from around here & in texas that have always gotten good results for me in the past.

Schurters LT1

I just put the car away Phil, but i have some data saved that i can send you it is data master, and a tuner cat file, How is this free scan tool? Do you have to pay or is it as it says FREE Ya all the help need
thx

atljar

Not to burst you bubble, but 117-118 traps isnt really impressive for what you have. You are still down some major HP if you are running around there. Im running 115+ traps with just the cam in fully loaded z, much heavier than stock, no weight reduction.

The exhaust would benefit from longtubes as im sure you already know. No experience with RK sports, so cant say what the design is like or what you would gain. Rest of exhaust looks good.

So that more or less leaves a few things that i would check into first. Bad tune (0 knock retard at ALL times, proper a/f ratio). Bad valve springs not holding up to high rpms. Pull some off and have them pressure tested. Hydrarev kit is good investment, or bigger springs. Finally, do a leakdown test on the cyls to make sure you have proper compression. Good luck bud.