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BradC
Dodge Dakota
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4/22/2003
22:11:47
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 Subject: running rich at WOT
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Have a 97 dak with the 5.2l
mods are as follows
hypertech pp III
M1 intake
k&n 14x3 air filter
crower 1.7 rr's
edelbrock headers
flowmaster catback
ported tb
ported heads 243 cfm intake, 180 cfm ex.
autolite 3923's
180 tstat
IAT adjuster
accel coil
Problem is at WOT the PCM is dumping way too much fuel. I'm running a 10.6 to 11.1 A/F ratio right now. Cruise and part throttle are fine (cruise is 14.7) Checked vacuum at WOT and pulled 1 inch. I know 0 is ideal but 1 shouldn't cause that much of a problem. Any ideas as to why the PCM would throw soo much fuel at it? This is with the hypertech 93 octane setting and the IAT off.
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big_torque
Dodge Dakota
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4/23/2003
08:31:42
| RE: running rich at WOT
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I think thats just they way were programmed to run. I have the MP PCM and it runs pig rich in the high rpms. Like 10:1
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rtdkota
R/T
 
4/23/2003
10:01:34
| RE: running rich at WOT
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Normal... if you ran a Unichip, or a custom flash you could dial some of that out. I ran 10.5-11:1 that dropped to 9:1 and off the scale at WOT with mopar perf. PCM.
My custom flash now shows a 12.2:1--- flat across the board from 3400 rpm to about 5200 rpm-- then drops to 11:1 up to 5800 rpm...
Run a set of stock range plugs and test again.
Sam
www.socaldakota.com
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BradC
Dodge Dakota
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4/23/2003
10:34:07
| RE: running rich at WOT
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Message:
Ok that's good to know. Can you explain why it falls flat on its face at about 4800-5000 rpm right up to redline? I shift about 5500 rpm. Has good power up to that point. It is a very noticeable drop off. Is it possible I need more injector? Valve springs have been tested to make sure it isn't valve float.
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rtdkota
R/T
4/23/2003
12:05:05
| RE: running rich at WOT
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Stock cam--- you make your peak power at ~4600 rpm-- the fall off from 4800 up is expected. Especially with the M1-- it's a single plane manifold, and tuned for a different profile cam.
Bet you get the nice 2nd-drive bog too at WOT...
My cam/heads made that bog about 1/8th of what it was-- and pulls all the way to 5450 to peak HP... I shift at 5600-5700 rpm
Sam
www.socaldakota.com
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BradC
Dodge Dakota
JOIN HERE
4/23/2003
12:44:00
| RE: running rich at WOT
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Interesting... That considered, what cam should I be looking for? Also remember I have the 1.7 rr's. Damn I was thinking of changing the cam when I had everything apart! live and learn.
Now I realize the dektop dyno is only a educated guess with optimum fuel control. Throwing the numbers I had in it had me peaking at 5500 rpm. You are on the money with the bog. Not real bad but it's there.
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