Doug G

Dropped exhaust at collectors


81* and 78% humidity...with weather coming in (hope it passes)

Now...what you think she'll do with no other changes exhaust was ???100#ish and a 2.5" dual system w/ H-pipe.

ZONES89RS

iTrader: (25)

Gain a couple mph and a tenth.

Doug G

I really hope for more than that

http://www.weather.com/weather/map/i...animation=true

speedtigger

iTrader: (16)

In for the results

CarbedZ-28

2 tenths and 3 mph is my guess.

98CayenneT/A

I will take 3 tenths and 4 mph

topbrent

iTrader: (1)

Are you going to bolt up some collector extensions?

ZONES89RS

iTrader: (25)

The exchange for HP for torque I think will not pick up that much, but I also conservative giving the results I would want to see from it if it was my car. If I go in expecting allot I get disappointed if I don't hit my hopes and dreams. Lol

3pedals

iTrader: (3)

in for results, good luck Doug...
bring some jets with you too, maybe try ad some jet front and rear after you run it with above changes

6D9

iTrader: (1)

Good luck!

Doug G

Track was ****. I watched them spray and drag, but I guess the humidity won out ?
Spun bad first pass on launch and at the 1-2 shift....just cruised out the back end.
Second pass, feels better (hooked), 11.61 @ 116.15 AFR on top end 12.6-8
Track guy tells me slow it down ??? said I went 11.0 on time board ...I get slip 11.61
Third pass, spun bad again, peddle it, hit second and pops a few times at top of second, hit third and it starts popping...let out and cruise out the back end. Head for truck.

I know this car can go faster, but seems it's stuck here in the low to mid 11's... WTF ?

I watched 1 wreck, and 3 oil downs...loaded up and went home. Storms coming and didn't want to get caught in it. Got home, car and trailer in garage....about an hour later it poured.

OH, and the exhaust is going back on

OH, and Dragtimes showed a 2414' DA so I punched in my numbers and...


Correct your ET and MPH using the DA

11.28 @ 119.622 MPH

Doug G

OK, looking at Best ET/MPH back in Oct'13
I made my 1st pass at 32* and went 11.80 @ 113.32...Now, not taking into account the DA This time out with the same settings I went .2 and 3mph faster dropping the exhaust. (I guess .1 could account for the weight ?)
34* made my best MPH at 117.71
36* made best 60' by .1, .01 better 660', and .003 better ET losing 1mph in the 1/4

I made no changes at the track since I only got 1 clean pass. I'm going back to 34*
This thing is still down on power SOMEWHERE

3pedals

iTrader: (3)

With respect to your timing, sounds like you need the 36* in it below tq peak and 32* beyond that. My similar engine made pk tq @ 5400 fyi.
The popping at the top of each gear sounds like a fuel supply problem. - check for crud in the needle and searts, and verify float levels are right

3pedals

iTrader: (3)

Something is definately off?
Did you check the cam degree Doug?

speedtigger

iTrader: (16)

If it were me, I would lock it in at 34 degrees and forget about the timing for a while. You have tested enough to know the timing sweet spot.

Next, here is what I would do:

• I would do a compression check on all cylinders just to rule out issue
• Replace all the plugs with fresh TR6s
• Check all the wires with an ohm meter
• Double check jetting to make sure it is factory jetting for that carburetor
• Make sure the powervalve arrangement is factory
• Double check the bowl's float levels
• Double check full throttle operation
• Double check all grounds and power supply to the MSD

Next trip to the track:

• Make 2 baseline runs. Make sure they are clean passes.
• Make sure the 2 passes have similar performance. If they do not, make another. You are looking for repeatable consistency to assure you have an accurate baseline.
• Next, jet up 2 jet sizes all the way around and make a pass. Must be a good clean pass. If is speeds up, jet up 2 more sizes. Repeat.
• If it slows down when you jet up, then jet down all 4 corners 2 jet sizes from factory. If it speeds up, repeat.

Once that is done, you will be confident about the timing and jetting and you can move on to other concerns like cam timing. Most important for me in these scenarios is to just stay calm, put my expectation away and do the work. I find it more enjoyable that way and it usually makes me more effective.

Doug G

Only was popping on last pass...I think it was due to low fuel level in the cell (thought I had half a tank I guess due to being on the trailer and not level ?)

Doug G

Didn't re-check the cam... I don't have those tools

Doug G

Looks like I'll be busy for a little bit

I just wish the combo I copied could give me so more info...would make this easier for sure.

I don't get to the track as often as I'd like, so tuning this thing is going to be a while.

Thanks for all the help....getting discouraged

3pedals

iTrader: (3)

Dont get discouraged Doug. Sometimes a certain combo takes some effort.
You wouldnt beleive the extra effort required to learn and tune a stick car

Petey-Pop-383

My 383 sbc I built in 2003 first time at the track was running 12.30s, I adjusted the timing from 32 to 38 degrees and the next pass it went 11.70.

I like to isolate aspects of the car and tune one thing at a time. I see too many people change 10 things after a pass and then go faster/slower and don't what change caused it.
You should be able to get some more out of your combo.
Good Luck!