gothic_sera

I had my first attempt at 1/4 mile yesterday - no mechanical problems at all thankfully but my speed and ET are awful...

First couple of runs out I got my shift points dialled in and made a minor fuelling adjustment after the first run.

I managed to put in 4 runs as the track was quite busy.

Best run of the day was 14.118@105.48mph

With a stock 4L80E converter it's never going to launch great, but to be honest I was expecting better. In each case I launched at 1850rpm which is as much as I can get out of this converter.

The 4 runs were:
14.200@105.08 (1st run)
14.247@104.48 (2nd run - hit the limiter 1-2 and 3-4 shifts)
14.294@104.90 (3rd run - hit the limiter 1-2 shift)
14.118@105.48 (last run - clean, launched at 1850 rpm)

Car is 2nd gen Camaro, carbon hood and front bumper (nothing inside it), full interior. Rest of the spec is in my signature including the motor. I guess the car must be about 3400-3500lbs

I have no traction issues off the line whatsoever, it doesn't spin the tires at all. Even with rubbish street tires.

I always knew I would need a better converter - what improvement should I be expecting after I've got that sorted?

I spoke to FTI and they recommended 4000rpm stall for my combination. I just need to save up!

gothic_sera

Here's a vid of the first run

346only

If it were my car it would have a th350 and a good stall and look for 10's on motor if it has a good tune. If it wouldn't run 10's I'd burn it to the ground.

Doug G

I get my best times flashing my converter by staging at 1000-1200 and going WOT on the last yellow
Good looking 2nd Gen....my BIL would give his left testy for that...lol

Taxman20

iTrader: (11)

I would weigh the car first. My S10 weighs 3250 with me in it, it had a LQ4 6.0 that's tired with about 180k on it and a 4L80E trany, stock converter. It ran 13.00 in the 1/4 and was a turd off the line of course. The LQ9 has more power to start with and you have a small build in it. You should be running in the low to mid 12's easy.

And if your going to race it stay away from the TH350. Its too weak. Go with the TH400 if you go with an old school trany. I am putting a powerglide in mine since is getting a turbo build now. The 4L80e can hold a lot of power, but its a heavy pig.

murphinator

iTrader: (2)

simple... you have created the typical turd stick scenario when you put a cam in without a high stall it will be slower than stock cam every time , convertor is going to help you out a lot.

I also agree with above about flashing convertor , if your holding it up against the brake to the highest rpm possible (sounds like 1850) I bet if you mash it from idle you get more stall out of it.

your trap says it has low 13's in it currently, hopefully the convertor allows it to get in and stay in its powerband and drastically improve that trap speed (shift extension) I would expect a heads cam 6.0 setup to trap over 120 and be in the 10's

What tire are you running on the back ? what size ? how tall ?

what were your 60 foots and 1/8 mile trap and et ?

1970camaroRS

iTrader: (8)

You're missing some horsepower somewhere. I'd expect you to trap well over 110mph. You said you hit the limiter? Why rpm is it set to and what rpm does it shift?

transam69230

iTrader: (49)

You clearly must have over estimated the hp of the car here, and your choice of transmission is not ideal.





@goth_sera the car should probably be in the 115-118 range for mph based on your mods and running mid to low 11s. Something is definitely up besides lacking a converter.

All your plug wires on? Do you data log you runs? Have you verified that when you depress the gas pedal the throttle body see WOT? You could have the pedal to the floor but the throttle could only be part way open.

How much timing do you have? Did the car get hot and the IATs climb and pull timing out?

Just some things that you can easily check.

SoFla01SSLookinstok

Right on. The car didn't sound too healthy for what it is. That's about the mph of a stock LS1 f-body. Did you build the motor? Another thing to check, if power is missing, is compression. Good luck!

gothic_sera

Thanks for the help guys. Must say I'm disappointed with the performance - I knew the converter would kill it a bit off the line, wasn't expecting it to be so bad.

It was a poor choice during the build and always something I planned to replace as soon as funds allowed. That might have to just be sooner.

I have a hunch that the converter might be a motorhome one... I don't know, I didn't pull it out myself. I had it cleaned by a supplier in the UK who also fiddled with it and increased the stall as high as they could - doesn't seem to have helped much. From my datalogs I'm only getting about 3-4% slip in the converter at full throttle - which seems crazy low - and given how tight it feels it doesn't surprise me.

I tried different launch techniques, all the same, stabbing the throttle or bringing it up to stall against the brakes.

I did data log the run - 12.5afr all the way except at very low rpm when I first launched it dropped to about 11.5. I pulled some acceleration enrichment out and got that a bit better on the last run but it made virtually no difference.

Timing steady at 24deg above 2700rpm. IAT are 30-35 deg.

Limiter set at 7000rpm - I reduced the shift mph a bit and it's shifting at 6850 now.

Rear tyre is 28" tall

60' was 2.505

Definately getting WOT

Plug leads are all on, all are new, Taylor spiro wound ones, none are burned.

I had a thought last night as to whether I'm pulling enough air through the intake tube to collapse it, I have a short 18" length of 4" silicone hose in there to get the filter away from the radiator. Might check that out as soon as the weather picks up.

I'm also going to check my cam timing and make sure I didn't screw something up there - although I checked it during the motor build can't hurt to double check it.

98CayenneT/A

That 60' is god awful. Even a 1.8 60' would get ya a solid 12 second pass. What about switching to a 26 in. tall tire also?
What was the d.a of those passes?
Imo at the very least you need a decent converter

gothic_sera

DA was around 500ft

The 60' felt god awful too, lol

Doug G

I think you're killing the power.
Are you running a MAP ? any added timing anywhere ?

I would try 30* from 1500 - 7000 with no added timing from the MAP.

98CayenneT/A

I apologize, I was under the impression you were spinning your way to a 2.5 60' when I posted this. Didn't realize you were not even turning the tires over until I just re read your original.

1970camaroRS

iTrader: (8)

At your weight and that trap, your making close to 330rwhp. That 60' with no spin says youre making very little torque. With that combo, even with the mismatched converter, you should have enough torque to spin the tires to a better, yet still slow 60'. And you should be making close to 400rwhp and trapping over 110. Somethings missing.

gothic_sera

Thanks guys.

I based my 24* timing on some stock maps I found. Several people told me these motors rarely need more than 26* to make best power? But then that's very combo dependant I guess.

The tune is speed density, so I'm using MAP for load. I don't have a MAF.

The weather in England currently sucks, so it's likely to be the weekend before I am able to work on the motor.

But I'm getting a list of physical things together to check out...

1. Verify TDC mark and check base ignition timing again. It idles best at 22deg and its steady at that.
2. Check cam timing. My cam has 108 intake c/l so I'll be sure it's set at that
3. Test with intake pipework removed
4. Do a couple of pulls and datalog - bit limited on where I can do this without a 150mile trip to the strip.

gothic_sera

Here's the current ignition table and fuelling table. Load axis is MAP.





I think the next thing for me to do is verify my cam timing is correct - perhaps I messed it up when I set it up during the motor build. It's simple enough for me to check out. Not so easy to put right if I did get it wrong.

Heavy H.P.

What gears do you have in the car?

346only

[QUOTE=transam69230;19279696]You clearly must have over estimated the hp of the car here, and your choice of transmission is not ideal.

I don't think the 4l80 is ideal. It's a big heavy turd in a low hp car. A th350 it that car with good converter would be faster. He still should be faster than he is. I think be should run 10's

gothic_sera

It's got 4.11's

I've checked the cam timing this morning and it's spot on 108 intake c/l per the cam card - TFFT! Also checked ignition timing and that's spot on too.

I've ordered myself an FTI converter, based on their recommendations an SRL series 4000rpm hard hit.

I could perhaps try giving it a little more ignition timing on my next runs too, I should be safe where I am, so I'll increase it 1 deg at a time and see if there's any improvement in trap speed.

The car was completely dead for 300' until the rpm got up into the cam power band - I should have expected that really.

With any luck my new converter will knock a good chunk of time off my ET and also bring my speed up a few MPH.

Oh and BTW... I'm a girl - the sort you parent's warned you about and every guys worst nightmare