Finally made it into the 11s BUT

[don86T]

My MPH seems a little low:
1.65 - 60’
7.57 @ 90.11 in the 1/8
11.89 @ 113.8 in the 1/4
The converter is locked at 80 and the motor was turning ~ 4700 thru the traps
The EGTs were 1642 (I have the FP up to 52 line off, at 44 the EGTs were 1700 +)
This was on a 24* chip and 25 # of boost with straight 110 in the tank and 0 knock showing on the Scan Master (with fast update).

Also I did some work to the heads, opened the throat, cleaned up the pockets and back cut the intake valves.

Is the MPH low and any idea why is it running lean? (009 injectors at 90% DC)

Thanks,
Don

 

[turbotwister]

tell eric nick said to give ya more duty cycle!


email me.we will discuss the situation.

Nick,

 

[sixgun86gn]

Don't feel bad I went 11.69 @ 113.You are really too rich I think.I had mine set like that too and it responded better when I backed off the fuel.Too lean can cause high egts and so can too rich.

 

[Quick6'n'-K.C.]

how much does the car weigh?

 

[Slow91z]

I didn't think about this at the track fri. but he's right...to rich can make unburned fuel go out the exhaust and burn in the pipes making EGT go way high...I should have thought about that then.

 

[don86T]

Quick 6'n'-K.C. 3750 lbs with me

Slow91z and sixgun86gn I can try to lean it out this weekend but
the scanmaster was only showing 680 mv and I wouldn't think that would be lean. oops! I meant rich


Nick I'll send you an e-mail

Thanks all

Don


:confused

 

[Slow91z]

Hmmm, 680 huh?? doesn't sound rich...is their anything OTHER then the motor that could be holding you back?? A dragging brake, or something similar?? Just a thought.

 

[sixgun86gn]

I do know that when you turn the pressure up that high the injectors cant flow as good.I backed out on mine and the o2s went up.I was locking up the injectors with too much pressure.

 

[Slow91z]

Never heard of that...Interesting concept, I'm gonna have to keep that in mind.

 

[Quick6'n'-K.C.]

sounds about right, car is tuned fine... not rich or lean, just about perfect on your EGT... i would get the duty cycle turned up some, or get a 7th orifice for more fuel... you make more power with more fuel

the MPH may be down because of the weight is high and top end charge isnt perfect... what exhaust does it have?

your car picks up 23.5 from half track on, THATS PRETTY GOOD, you just need to get more MPH in the 1/8th so the top end charge shows more MPH...

if you have a restriction in the exhaust, that may be the reason why the MPH isnt as high as you want it...

change the plugs and 02 before you go back out and see if it picks up any.... try that and see what happens..

BW

 

[don86T]

ATR single shot exhaust

Plugs are cr42s with 15 passes and 2 trips to the track but I didn't lower the fp for the trip. I wanted to close the gap to .034 so I guess I'll just put a new set in.

O2 sensor ??? passes, still cross counting well

I am going to lower the fp some after the first pass to see what happens.

Thanks,
Don

 

[QuickWrench]

Just a thought...

The converter is locked at 80 and the motor was turning ~ 4700 thru the traps

Any chance you're going through the traps in 4th gear?

 

[don86T]

Originally posted by QuickWrench
Just a thought...


Any chance you're going through the traps in 4th gear?

No, 3rd gear with 28" tires

Slow91z There is no indication the brakes are dragging but its easy enough to check.

 

[bruce]

Originally posted by don86T

Is the MPH low and any idea why is it running lean? (009 injectors at 90% DC)

Your out of injector.
You can play the headgasket game, or go large enough to actually have a decent fuel curve.
55s as a min, perferably 72s.

90+% DC is a crappe shot for when the injector starts going erratic.


For the operating PSI comment as you increase the operating pressure it reduces the possible fuel flow. So you can run out of pump easily. Some time ago the Sy guys flowed some injectors us to operating pressures of 130 and they were linear all the way, the fuel bench ran out of PSI is what halted the testing.

 

[V8KILLR]

Get some bigger injectors......I like my 55s. Run some C16 and push the timing up to say 28*. What turbo do you have? If you have a big boy, jump the boost up a little. This is all said if running it, you are tuning it slowly, pushing it up and you'll mph.

Jason

 

[don86T]

Well a quess for now I'll have to be satisfied with the 113 mph. I have gone 112 without high fuel pressures. I just put head gaskets on and don't want to again. (someone had put n/a gaskets on it and they didn't hold up).

With all said 11.90s with a TA 49 and a 3750# car is ok.

Thanks for the input,
Don

 

[QuickWrench]

First of all, great times. Congratulations, looks like you're enjoying the car.

the scanmaster was only showing 680 mv and I wouldn't think that would be lean.

Um...this is DEFINITELY a lean O2 #. O2's in the .6xx range usually forecast a head gasket change.

Your out of injector.
You can play the headgasket game, or go large enough to actually have a decent fuel curve.
55s as a min, perferably 72s.

...

Get some bigger injectors......I like my 55s.

I'm just not in agreement here. I've had 2 TRs with a very similar combo to yours (Dutt necked stock IC, TA49, stock drivetrain), and both cars went 11.4x - 11.6x on 36# blue tops. Granted...the blues were maxed out. 42.5# 009's should be absolutely fine for your combination.

What I'm wondering is this...

The car's lean on the tall end. What are your O2's throughout the duration of the run? (I use Direct Scan; I've never used a Scanmaster, so I don't know if it logs the entire run, or just reports back peak/valley #'s.) I can't tell from your sig or posts what fuel pump/wiring setup you have, but have you monitored the fuel pressure during the course of the run, or are you just doing the "set it and forget it" before your pass? If your pump/filter/lines/wiring aren't up to the job of supplying the pressure you need on the tall end of the track, you wouldn't know, unless you actually watch the pressure during your pass. The O2 #'s would simply drop, EGT's would go high...but you wouldn't know if it was due to injector sizing, or inadequate supply.

 

[don86T]

I am most definitely enjoying the car they are still the fastest for the least investment.

As for the scan master it on record min 02 mv. I could have watched it through the run but I usually watch for knock and glance at the boost and fp gauge.

As far as fuel pump it is a fairly new 340 hot wired and the fuel pressure through the traps is a steady 78 psi (the gauge has been checked against another gauge for accuracy). So I don't think supply is an issue.

I'm starting to think since I ported the heads, I thew my combo out of wack.

This weekend I think I will turn down the boost and fp. If the car 60's as well it may be almost as fast.

Thanks again for everyones input. With a few more runs this weekend I should know for sure.

Don