dyno results.. How do i fix this?

moneypit94

Active Member

May 23, 2003

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Macomb, IL

Aug 12, 2004

#1

• Aug 12, 2004

• #1

BTW, I told him to take it too 6000 rpms on the last run. Otherwise he wouldn't let it get that lean.

What a long day... I just got back from AFM.. Got a few questions..

Ok as you can tell i start going lean and its uncontrollable... Found out today that my 42lb injectors are maxed out at 4300 rpms. Which is about 1000 rpms too early for the power its making.. Well Danny, my tuner, said he thinks that the pumps aren't pushing enough fuel and thats why the injectors are maxing out early...

Well i have a holley (walbro 255) intank and i just replaced my walbro inline 255 with a t-rex. I have replaced all the plastic fuel line.. Only thing i haven't replaced is the steal lines and fuel rails.

Oh and my belt was slipping pretty bad... I made almost 12lbs of boost which shocked me after i tightened it up a little.. That brings up my next question.. Even after i tightened it, two runs later it started to slip.. Does Vortech make a cog replacement system... Want to keep it where its at, far as the stock pully sizes and stuff go.

And what about a boost a pump.. Im running out of options..

 

9

94DreamGT

Founding Member

Jul 19, 2000

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Indiana

Aug 12, 2004

#2

• Aug 12, 2004

• #2

I had a buddy with similar problems. Has a 91 5.0 notch with Trick Flow H/C/I/S-Trim @ 15lbs. Was running 42lbs and it wasn't enough fuel.

He went to a full Aeromotive setup with lines, rails, sumped tank, etc... Really did the works. Might've been overkill, but he's thinking of going with a stronger block and maybe a Ys or T trim.

I don't know if that's what you're looking for, but it definitely fixed his problems.

 

Sleepy McNastee

New Member

Feb 5, 2004

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Lawrence, KS

Aug 12, 2004

#3

• Aug 12, 2004

• #3

Throw some more money in the pit! New fuel system with lines and everything. I don't think I want to know how much that is.

Those are good #'s btw , even though it's scary lean.

 

S/CBlack95GT

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Apr 6, 2003

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Tampa Palms, FL

Aug 12, 2004

#4

• Aug 12, 2004

• #4

Toss an FMU on it. That will cure the lean problem.

 

YEAHLOH95

Founding Member

Nov 19, 2001

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EVERETT,PA

Aug 12, 2004

#5

• Aug 12, 2004

• #5

i don't want to sound like i'm being picky but isn't the torque and horsepower supposed to cross at 5252 and your does at like 57XX and yes i think an fmu might help you , my friend with a fox is having the same trouble going lean ands he keeps blowing head gaskets but he is very close to running 10 's though too!!

 

moneypit94

Active Member

May 23, 2003

1,723

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Macomb, IL

Aug 12, 2004

#6

• Aug 12, 2004

• #6

YEAHLOH95 said:

i don't want to sound like i'm being picky but isn't the torque and horsepower supposed to cross at 5252 and your does at like 57XX and yes i think an fmu might help you , my friend with a fox is having the same trouble going lean ands he keeps blowing head gaskets but he is very close to running 10 's though too!!

Click to expand...

well they do meet at 5200 or whatever... its just that both sides are measured differently..

Im going to have to look into this fmu deal... i was always told i wouldn't need it with 42's... hmm

 

4Jenna

Founding Member

Sep 12, 2001

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AZ

Aug 12, 2004

#7

• Aug 12, 2004

• #7

A Trex is only like a 190lph I thought?
I was told 42's are good to about 550rwhp. Good #'s...I know how you feel with borderline needing lines/rails

 

Killercanary

The car that set the bar.

Founding Member

Nov 29, 1999

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Altoona, PA

Aug 12, 2004

#8

• Aug 12, 2004

• #8

The guy yeahloh95 is speaking of just put down 516rwhp today at 5500rpms in his fox body. His combo is TF stuff with ported heads, cam, intake with a paxton novi 2000 with 14lbs of boost. He only has a GSS340 in tank, but he too went lean. I think he just needs some more fuel pump. He made 480rwhp with 12lbs of boost, and he is running a 302 cubic inch stock block based motor. Do you have the GSS340 walbro? If not, that might help you with your problem as it is the high pressure, high flow 255lph pump, not the normal 255lph one.

 

4Jenna

Founding Member

Sep 12, 2001

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AZ

Aug 12, 2004

#9

• Aug 12, 2004

• #9

yeah true
you need the high pressure intank

 

moneypit94

Active Member

May 23, 2003

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Macomb, IL

Aug 13, 2004

#10

• Aug 13, 2004

• #10

Thanks for the info guys... I will look into the high pressure intank... Cause the inline is only going to push what the tank feeds it right?

I think there are two types of t-rex pumps... The one i have is a 50 gallon at 70 psi.. Which if you look at the graph of the walbro 255... it does the same at 70 psi..

Now does anybody know about a cog replacement system? I mean it should be just two pulleys and a belt.. but knowing vortech it would cost 500 bucks or more..

And if the fuel pump isn't good enough then i have the option of the fmu if needed... now that i think of it, that should correct the problem..

Im pretty happy though even though im going lean.. if i could just break that 500 barrior i would be satisfied.. 500 rwhp/600 hp at the motor daily driver... And i got 21 mpg, highway the other day.. minus the factor of the 3.73's and having the wrong internal speedo gear.. Still not bad though..

But im a little scared to take it too the track till it fixed completely...

 

4Jenna

Founding Member

Sep 12, 2001

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AZ

Aug 13, 2004

#11

• Aug 13, 2004

• #11

You need the HD bearings in a S-Trim to run a cog drive.
They also don't recc it on the street but who cares I say..I've thought about it also but I know my block will for sure split!
You'll make so much more down low, and up top...oh yeah you'd have to brace that sucker also.

Chris