74u

iTrader: (9)

I had a chance to get the car back to the track Friday night. I recently swapped from a Powerglide to Jakes Performance TH400. Previous best was 11.72 @ 118 in 2300 DA.

Now with the new trans and and some jetting I was able to manage a 11.32 using a very low 3000rpm launch on the trans brake. DA was 2375..here is the break down.

http://s41.photobucket.com/user/wh62...560f4.mp4.html

1.67
7.28 @ 97.0
11.32 @ 120.4

The car went 11.39 @120 the pass before without using the brake and launching just above idle...

http://s41.photobucket.com/user/wh62...72ad4.mp4.html

1.72
7.33 @ 96.5
11.39 @ 120.4


Here is my basic set up...

89 Notch - 2880lbs. with me in it
2000 LS1 stock short block
Stock 853 heads
Lunati 238/243 - 600/600
Vic Jr.
Holley 750 HP w/77 jets primary & 78 jets secondary
timing is 33 degrees all in by 2200rpm - shifting at 67-6800rpm

TH400 - Jakes stage 2 w/brake
FTI 4000
3.73's
Hoosier DOT drag radial 275-50-16

For a pump gas car that I drive 35 miles to and from the track I'm happy with 11.30's but really want to see a 10.90 before I spray it. I'm sure I could get close in good air, but 2300 DA's are the reality for most of the racing season where I live.

What would you guys do next? My rear suspension is completely stock as are my axles. I'm planning to upgrade the control arms and axles pretty soon and then I will be able to hit it harder with the transbrake. I'm sure I will pick up a couple tenths on a good launch but I still think my MPH is a little low for a 10.90 pass.

speedtigger

iTrader: (16)

Sounds like your car likes the 3 speed.

I would think that combo would go 10.70s.

74u

iTrader: (9)

That's what people keep telling me but where am I losing 6 tenths?

I've jetted & timed it for best MPH...the tune has got to be close. It's a street car so gearing is about as high as I want to go. The converter feels a bit tight...I'm thinking it could be a bit looser (maybe make it a 4500). Wouldn't hurt streetability much.

ZONES89RS

iTrader: (25)

The heads are holding back over other pieces but your 60 needs to come down. I'm heavier with a truck engine hitting 1.5s with no brake and 3.73s.

speedtigger

iTrader: (16)

Did you plug your primary side power valve?

onefast84

Put a bigger carb on it! It needs to breath!

onefast84

Also try shifting at like 6000 rpms, or maye even 5500. My car goes slower when I shift that late.

speedtigger

iTrader: (16)

Really? Your valve springs okay? That is very un-LS like.

74u

iTrader: (9)

Agreed...some axles & control arms and I'll be getting a lot more aggressive with the transbrake. As of now I just set it to 3000 and it barely went any faster than launching off idle on the foot brake. I'm debating whether I want to do heads & a rod piston combo on my LS1, or go grab a LY6 and start over. I'm kind of leaning toward a piston/rod heads on the LS1...should make for a tough, light weight, high revvin little motor.



No...still has PV on both sides. Is there an advantage in blocking one of them?


I forgot I have a Pro-Form 850 in the garage...just needs new gaskets and I could throw it on for a test.

Now that is jetted this thing pulls to the top...I believe shifting at 5500 - 6000 while N/A would be a big step backwards.

onefast84

The vs are new. It just went 3 tenths slower shifting at 6700. I just think the 825 is holding it back. or in his case the 750.

speedtigger

iTrader: (16)

3 tenths slower! Yeah, something is seriously wrong. An over shift should be hundredths. I have seen people post that they had valve float problems with aftermarket roller rockers. As I understand it, they are heavier and require a lot more valve spring. I would be very tempted to throw some upgraded stock rockers on there and run it. You may pick up big time.

speedtigger

iTrader: (16)

Not necessarily. The only reason I brought it up is because your jetting surprised me, but if you have power valves front and rear, that would explain it.

dogsballs

power valve channel restrictors could be opened up in front and then you could jet down on front. same end result but tipping less fuel at start, more geadual increase with vaccuum.

6D9

iTrader: (1)

Is the 750HP the street hp or regular Hp?

74u

iTrader: (9)

Not sure. It doesn't have provisions for choke, and has mechanical secondaries...does that help?

6D9

iTrader: (1)

Is the carb gold or silver in color?

74u

iTrader: (9)

Silver

6D9

iTrader: (1)

Its the street hp750 then. It should have a PV in the primary and be plugged in the secondary. In my 406 sbc it was jetted 72/80 for a 12.7 ish a/f ratio. Is the link below the carb?


http://www.holley.com/HolleyNews/article.asp?ID=24

74u

iTrader: (9)

Mine has #6.5 PV's in both sides. Bought new this way with 73/73 jets on both sides. The carb in the link from memory looks identical to mine.