Lousy 60' Times.

[motorhead]

I had a serious issue with launching my T at the track on Saturday...

1) Build 4-6psi @ line
2) Lift off of brake
3) Stab gas
4) Car falls on own face
5) Picks up after a 2.2 or worse 60' on slicks
6) Runs sad mid-14 passes, with MPHs in the mid-90s.

Probably related to my off-idle/low speed cruising surge.

Any thoughts?

 

[UNGN]

Swap 2 and 3.

If the car falls on its face, you need to leave with more boost.

 

[motorhead]

Are you implying that this could just be some ugly lag from the stock turbo?

 

[salvageV6]

Gas to the floor just as you release the brake or a bit sooner is what I think he is saying.

 

[Spoolinup]

Mr.T you have a ton of mods and two things really stick out here.

You have the stock turbo and the atr double pumper?

I know we all should mod the fuel system above future plans, but thats overkill.
Did atr recommend that pump with the twin 242's?

Is the double pumper on all the time, or do you have the one pump on and the other turning on later?

What is your blm at idle?

Sounds like the car is so fat down low that even 8 psi would still not get it out of its own way.

You might be having return issues on that huge pump also.
Do you have a complete billet afpr, or the stock bottom half with the billet adjustable top?
The return orifice is .18 on the complete billet ones like CAS carries compared to .14 the stock orifice is. A big difference in what the reg can return back to the tank.

 

[UNGN]

Originally posted by Mr. T
Are you implying that this could just be some ugly lag from the stock turbo?

No the ugly lag is probably coming from the double pumper overwhelming the FP regulator and then overwhelming the airflow provided by the stock turbo. Your car is probably way rich at launch or .5 seconds after launch when the second pump kicks in. I'm not familiar with double pumper tuning. With your parts, I sell it and get an intank single. much simpler for 11.0 and slower.


I mat the accellerator pedal before releasing the brake. That way, I get the maximum possible boost the brakes will hold before I release the brakes.

 

[John Larkin]

I'd agree with the bottom end richness. Last time out I was baselining the new combo. First run was horrible, EGT 1081, car was lame until it hit mid 2nd gear, then it took off like crazy. 5 runs later, 1550-1600 EGT and got the time listed below. All I did was drop one pound of fuel out each run (from 42 line off to 38 line off) until the 5th time and then I just decided to give it hell as is. Only saw 0.7 KR at some point.

And depending on the slicks, you are somewhat at the mercy of the track prepper. If they don't spray, you won't get stunning 60' times. On the first burnout, cook 'em until you can't see out the back window (5-6 full seconds). Then medium ones should carry you through the evening.

 

[motorhead]

Originally posted by Spoolinup
You have the stock turbo and the atr double pumper?

...Heh, yeah.

I know we all should mod the fuel system above future plans, but thats overkill.

...LMAO.

Did atr recommend that pump with the twin 242's?

...Nope.

Is the double pumper on all the time, or do you have the one pump on and the other turning on later?

...Nope again, should be engaging at 14psi as per the Hobbs switch.

What is your blm at idle?

...It is in the clean 128+/- range... it stays in TurboLink's green bar the whole ride.

Sounds like the car is so fat down low that even 8 psi would still not get it out of its own way.

...My money is on... I dunno.

You might be having return issues on that huge pump also.
Do you have a complete billet afpr, or the stock bottom half with the billet adjustable top?
The return orifice is .18 on the complete billet ones like CAS carries compared to .14 the stock orifice is. A big difference in what the reg can return back to the tank.

...It has a rather large all billet FPR -10 AN in, and -6 AN out/return lines.

Note: I bought a rolling chassis (sans-engine) of a former 10 second DFI car, and stuck a stock LC2 (80K miles) back in it.

UNGN: There is no way I am redoing the fuel system in this car, even though it still has the stock lines in place... I am not touching it. Not because I like the pretty braided lines, but rather it means that I will be pulling the trans to feed the AN lines out of the engine compartment. This car was psycho.

I really need to get some pics posted.

 

[motorhead]

Originally posted by John Larkin
I'd agree with the bottom end richness. Last time out I was baselining the new combo. First run was horrible, EGT 1081, car was lame until it hit mid 2nd gear, then it took off like crazy. 5 runs later, 1550-1600 EGT and got the time listed below. All I did was drop one pound of fuel out each run (from 42 line off to 38 line off) until the 5th time and then I just decided to give it hell as is. Only saw 0.7 KR at some point.

I hear ya. I have had the pressure as low as 40.5 psi, and still only registered 1 knock count, and 1.1* of retard at ~17psi peak... on 94 octane... nothing worth writing home about... I just upped the pressure to 44 to try and get he part throttle surge out of the car.

It is never wise to buy another man's project.

As for the burn outs... roast I will