Speartech

iTrader: (14)

I'll see where I end up with this thing; those 2" headers look very nice and I'm sure would be worth something on a 408" engine!

That Y looks good too. I don't have the room to lay one out quite like that.

Thanks for all the help on the exhaust system!

3.8redbird

iTrader: (3)

time to change the sig

Speartech

iTrader: (14)

Good point!

firechicken76

iTrader: (14)

Nice exhaust setup!!! Im going to do my exhaust eventually too. how much of a gain did the headers and exhaust make total?

Speartech

iTrader: (14)

Got the small pulley on over the weekend. It shows a good 12 psi on the gauge now. That should be about where I want to be with this setup.

I took it back to the track Wed. night to try it out, but it was a bad day weather-wise for drag racing. It was about 90 degrees and humid (compared to a nice 60 degrees last Wed.).

My 60' times were off by a full tenth for whatever reason, and my best ET of the night was a 10.31 (compared to 10.22 last week), but even in all of the heat, the MPH went up to 135.29 (compared to 132.17 last week).

Here's a good pic of it launching last night:




I think on a decent weather day it'll all come together!!

mightybird

did you change anything in the tune ?

Speartech

iTrader: (14)

I logged the first pass to see if there was any knock, and then added 1 degree of timing for the remaining runs; that's all.

1986irocz28

iTrader: (5)

subscibed

Speartech

iTrader: (14)

I took the car back over to the track on Wed. night.

I added 10 gallons of 100 octane unleaded race gas to see what that would do.

I also added 1 degree of spark advance in the higher load areas to see how it would do with the good gas.

The car responded well! (I'm in the left lane)




It's really nice how the car responds as expected to changes, ever since I added the headers and the free flowing exhaust system!!

With the stock exhaust manifolds, I'd make a change and it might be faster on one pass, then slower, then maybe faster again; stuff just didn't make sense. Now with the good exhaust, the car is repeatable, and when you make a change, the car does what you would logically expect it to do.

The problem I'm having now is that since I've gone to the smaller pulley on the SC, I'm having problems on the launch. Since the boost is instant on these things, I'm blowing the tires out a little bit when I hit them with the 12-13 psi off the line.

I've lost a full .1 - .2 of a second on the 60' times, so I need to do some more chassis tuning in order to get the 60' times quicker instead of slower.

I have to either get the chassis to hook better on the higher boost launches, or limit the initial boost until the car gets moving.

Still, the 10.teens @ 138 is feeling pretty good!

Now if I can just get back to those 1.44 60' times.

Stay Tuned!

Yun Gunz

nice, good work man

rsz288

Sounds like you solved the torque/throttle limiting challenge there John?

Boosted One

iTrader: (6)

Great results!! You have to be very happy with that mph! Very impressive motor! Can you bring in torque management mildly till X rpm in order to get the 60fts back in line?

Frank

Bob@BruteSpeed

iTrader: (16)

John, you should wait and run on weekends. Wednesday's test & tune nights are a waste of time when you have a high horsepowered car. The track is never prepped as well as it is for the weekends, and too many street driven cars come in and run on Wednesday nights.
You'll be in the 9's with a prepped track! Bob

Speartech

iTrader: (14)

I probably could do something like that, either with torque management or there is an unused solenoid on the SC bypass valve that could be wired and pulsed to limit boost for X amount of time.

I'll look at the options.

Speartech

iTrader: (14)

Ian,

Right now we are doing some product development (non-4L70E) with the car, so I have a TCI box running the trans. No limiting going on with that! I like!

Speartech

iTrader: (14)

You're right Bob, I should bring it on a Saturday and try it out.

I've always been a Wed. night guy, since testing and tuning is really all I'm ever doing at the track, but I would like to take advantage of some good track prep and see what it would do since the car is running so well.

I still have a couple of adjustments to play with on the M9 torque arm too!

Boosted One

iTrader: (6)

hmm, if that's the case then an eboost2 may be a great option. It pulses a solenoid to control boost.

BrazenBeast

John, what did you do for the oiling system on this. Did you stick with the dry sump and if not what did you run? If you stuck with dry sump what oil pan did you use? I'm working on planning a project with either the 2300 or 1900. Thanks and sweet car.

Speartech

iTrader: (14)

Thanks. I'm running wet sump with the LS1 F-body oil pan.

Speartech

iTrader: (14)

BTW, I'm just waiting for a chance to get back on the dyno and see where it is with the smaller pulley.

It made 564hp/582tq with the big pulley at 9 psi, so the numbers should be a little better on the small pulley since it brought the boost up to 13#.

I also need to get back to the track and try out some of the suspension setting changes; I just wish this 90 deg. weather would go away for awhile.