svslow

Had my first ever track outing tonight. The evening started off pretty hot but eventually cooled down and I got one OK pass in. Car felt good, just seems like I am down on power somewhere.

'84 fox body, full interior, no weight removal

5.3 ~9.5:1 compression
Stock 241 Heads w/ Lunati single spring
TFS 216/220 cam
S475 1.10 A/R, 83mm
TH400


Running on 110 octane and 18psi/11-12 degrees. Tune looked good. I know the 60' sucked but I still think I should trap quite a bit more. Converter slip was only 7%. The only thing that looked weird in the log was the IAT. I have a big Precision A2A cooler and there was about a 70 degree rise throughout the pass from 105-175*F. Seems to be using fuel, about 80% peak DC on the 80lb injectors in 3rd.

Best pass was of the night was
60 - 1.60
330 - 4.35
1/8 - 6.61 @ 109
1/4 - 10.23 @ 135

How far off am I?

MY_2K_Z

iTrader: (1)

Does seem a bit slow. I'll be interested in what others have to say.

3 window

iTrader: (1)

On the log it looks you're running 13 psi, not 18, correct? What's the timing a timing ramp look like as you made the run?

svslow

The image didn't come through as good as I hoped, boost is the red 18.00 near the center. It left on 23* and just slopes down to the 11-12* from there.

3 window

iTrader: (1)

I we here you're seeing the 18 in the center, but at left it says max is 13, no? Really small for me to see on my phone. Lol

springer_4

iTrader: (9)

Were you running at Milan tonight?

svslow

Yeah I was.

springer_4

iTrader: (9)

Your Car is BaddASS, Car didn't seem slow at all. Track was really shitty tonight Air did get cooler as the night went on, I seen 2 of your passes only thing I seen was Boost seemed like it was coming on kinda late. But I could be wrong.

svslow

Thanks! It was way too hot early on. I pretty much leave off idle. No trans brake and my brakes aren't good enough to hold the car back.

a05c

You'll get it figured out, especially with no trans brake or way to build boost before the hit.

PM Me if you need help with anything, I don't live far from Milan.

1999Black_Z28

iTrader: (1)

I would also expect higher trap speeds in that chassis (~3100-3200lbs?) with that turbo at 18psi. The only thing I can see is your timing is fairly low, especially for 110octane

Forcefed86

iTrader: (4)

Need to get the weight of the chassis to guess... Trap speed won't be affected much by a poor track surface...et will. I'd guess you have some MPH hidden in that combo for sure. Keep an eye on your converter slip and sneak up on the tune a degree at a time watching MPH and plugs.

Sure you're still at 9.5:1 with the larger 67cc 241 heads and LS9 gasket?

for comparison I believe I went 143 at 3000lbs on 17lbs with a very similar combo... only 2900lbs though... Also 175 is pretty darn high IAT wise. I'm under 130* at 20lbs on my combo with temps starting in the 100* range similar to yours. Using the 1200hp treadstone core.

forcd ind

iTrader: (7)

I was thinking the timing was kind of low for 110 also-reading the plugs would help, but its hard at a track, limited passes, and you need to pull them right after a pass for an accurate reading.
You are not far off from a 9 sec pass though-what plugs are you running

Nitroused383

iTrader: (10)

I gained 10 mph by leaving in boost it makes a huge difference.

svslow

The motor is 9.5:1 with Wiseco pistons. I'm just using LS1 MLS head gaskets. I will go back out again here in the next couple week when it's hopefully cooler outside. Maybe try a hair more timing.

svslow

br7ef

Forcefed86

iTrader: (4)

I’d look into the IAT thing, somethings off there. Maybe test your sensor or try another? What are the IC dimensions? Even when I ran the cheapie ebay cooler (32x12x3) I only saw 170 at 25+ lbs when it was 90* or so ambient. (same turbo as u run on a 5.3)

You usually go by ambient temps VS IAT, not the heat soaked under hood temps reported by the IAT while staging. So if it was 80* ambient, that’s a 90* rise. Do you have fresh air supplied to the turbo? or is it sucking in hot engine bay air? My under hood temps and starting IAT are similar to yours always. But as soon as I start the run they drop down, then start to climb.

93camaro_zzz

iTrader: (13)

Holy crap, 70* rise from the intercooler? I am getting only a 35-40* rise from the cheap 31x12x4" china intercooler. Also on 1/4 mile pass. This is one problem to investigate.

svslow

My intercooler is old. It's been on the car for 7-8 years, if I remember is the "750hp" version Precision made. Has the cast end tanks. The turbo does not get a very good supply of air. The inlet faces the fender apron and there is not an opening in the apron for fresh air to enter. I can get some pictures tonight. My IAT sensor is in the charge pipe a few inches down stream of the throttle body.

dburt86

iTrader: (2)

Possible boost leak? Turbo overspinning to come up to the 18psi, late spool, hot iat's?

But it doesnt seem that far off. Maybe 5-7mph?