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Discussion Starter · #1 ·
OK - I definitely need to add a high speed bypass to my alcohol injection motor.

I thought I was running out of gear. In reality, I get so rich the motor justs lays down at higher RPM. By 6800 rpm I start sputtering. Motor struggles to gain RPM on the top end, and I just stop accelerating.

Currently running 5.69 @ 121, but only make it to about 140 +/- 1 mph in the 1/4.

Who's high speed bypass should I buy, and where should I buy it?
What's a good price?
 

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You can buy one from Enderle Fuel Injection. 805-526-3838 If you don't already know, try to find out the fuel pressure at max RPM's. That will help to get a starting point for the poppet pressure.
 

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Discussion Starter · #4 ·
You can buy one from Enderle Fuel Injection. 805-526-3838 If you don't already know, try to find out the fuel pressure at max RPM's. That will help to get a starting point for the poppet pressure.
I don't currentlt have a fuel pressure guage at all. Where's the most appropriate place to plumb it? Immediately after the fuel pump?
 

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After the pump, or you'll get a pressure spike after your burnout. Between the barrel valve and the inhector somewhere, or off of an extra port in the distibution block. Unless this is an alky carb setup, then I'm no help at all.

And you'll want a pressure gauge with memory so you can check it after the run.
 

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Discussion Starter · #7 ·
http://www.goodvibesracing.com/hi-speed_assy.htm

Pump, 3-way, filter, hi-speed, hose to barrel valve.

Or, you can put it between the barrel valve and dist block for the port hat or port nozzles.

Please say you're using flowed nozzles and not stock shit.
Sadly, I'm so green I admit I know nothing.

I have learned of Spud, and at least I now know what a high speed bypass is.

I bought a car turnkey with an Enderle Hilborn-style methanol injection setup (individual throttle bodies).

I've figured out the whole main bypass deal, and have successfully tuned it for max power.

But:

1) Nothing I have has been flowed (obvious room for improvement #1)
2) No hi-speed bypass (obvious room for improvement #2)

At least I'm asking questions, right?

Thanks guys. Tons of great info in this thread already!!!
 

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Spud Miller
Dave Koehler
Ralph Gorr
Les Davenport

All guys who do nothing but setup fuel systems.

Then there are various Pro-Mod guys who do it on the side for extra cash. Brian Robbins comes to mind, as well as Bill Kuhlman.

Have all of the nozzles/jets flowed, or you're just as well to leave it alone. The stock shit is so bad (doesn't flow as labeled) that you can go up 3-5 sizes, and not change a damn thing. You MUST know what you have before you can tune anything.
 

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Discussion Starter · #9 ·
Spud Miller
Dave Koehler
Ralph Gorr
Les Davenport

All guys who do nothing but setup fuel systems.

Then there are various Pro-Mod guys who do it on the side for extra cash. Brian Robbins comes to mind, as well as Bill Kuhlman.

Have all of the nozzles/jets flowed, or you're just as well to leave it alone. The stock shit is so bad (doesn't flow as labeled) that you can go up 3-5 sizes, and not change a damn thing. You MUST know what you have before you can tune anything.
Thanks again.

I know where to get ahold of Spud. Any contact info for the other guys?
 

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Discussion Starter · #11 ·

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What size pump do you have? I've never had a car do what you say yours is doing because I didn't have a high speed leanout.
 

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http://www.koehlerinjection.com/

http://www.gorrfuelsystems.com/

Les Davenport - Phone 403 938 6200

Brian Robbins - http://www.skinnykidracecars.com/dragracing

A-Team Auto (Rob/Randy Adler) - 708-633-1320



Google.com is a magical place.

You might also want to educate yourself with "Fuel Injection Tuning Secrets" from Bob Szabo: www.racecarbook.com
x2 on the Szabo book. I got it a few weeks back and it is A LOT of help. It's more in depth than your usual how-to books.
 

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I'm hitting 1200 degrees +/-15 on the EGT any given run.

:smt017

Maybe the pump inlet is cavitating at high rpm. Incorrect feed size, forged fittings etc.

There is alot of things that will make the mechanical pump not perform as designed. Tank vent size comes to mind also.
 

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Discussion Starter · #18 ·
Tank vent size comes to mind also.
That's a curious thought. My tank cap often feels very tight trying to remove it after any given run. As if there had been vacuum in the tank.

Vent line is -6AN I think (without looking of course).

Perhaps that could be an issue down track as the tank is emptying?
 
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