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Discussion Starter #1
I have an 89 Mustang 5.0 w/ AOD installed in my 67 Ranchero. Since installing I have added 150,000 miles to it. With over 200,000 miles its time for a refresh. I will be using a Ford RP 306 (340hp) crate motor and installing an Explorer intake and FPA tri "Y" headers. On my old engine I left the EGT intact, this time I plan on blocking it off. What are the thoughts on this?
Also I'm thinking of running 30# injectors. What size throttle body and mass air meter would you suggest? This car is street use only has 3.50 gears 235x60-15 tires and weighs 3750#.
Thanks
 

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Are you using the OEM fuel injection?
 

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There are 3 options for EGR block-off in the GT40 intake. You can:

  1. Use intake gaskets that have exhaust crossover blocking pieces, such as the Fel-Pro 1250.
  2. Plug the passage at the top of the lower manifold with a core plug (freeze plug) or tap and plug.
  3. Remove the EGR and make or buy a simple plate to block the passage.
Notice I ordered them 1-2-3, as that is the preference. Each successive method allows heat farther up into the manifold, and that's not good for power. However, if your ECM will control the EGR properly, deleting it will result in lower mileage and you may also get some mid-range detonation. EGR benefits both of those. While often considered an 'emissions' device, it's primary function is actually mileage and efficiency. Folks often think it's for emissions, as a secondary side-effect is to cool the burning charge to suppress detonation, and that coincidentally causes a reduction in NOx emissions.

If someone asks what EGR is really for, tell them straight - it's to reduce pumping losses at part throttle and increase dynamic compression at cruise, while suppressing detonation from greater ignition advance for efficiency. :tup: Taken a step further (not for the average street car), you can slightly richen your cruise to make more CO (carbon monoxide) instead of CO2 (carbon dioxide) and run more EGR, burning at high compression or boost without det - as it's actually running mostly on CO. The air and fuel are just added to generate CO that is then burned by the engine. CO is a powerful and very high octane fuel. Audi is testing a 4-cylinder street engine that produces over 450 hp on 70% EGR. Mileage is a secret, but indicated that it's very high.

Anyway, I'd also say the 30# injectors are overkill, as 24s will handle 340 hp. No reason to reduce your low-speed control with flow you can't use. Run the math and take your pick:
InjectorSize = (HorsePower * BSFC) / (#Injectors * DutyCycle)
So, (340*.50) / 8*90) = 23.6#
This would allow a large stock MAF such as the Explorer, Cobra, Lightning, or Lincoln units along with common data files for chips or burning. But it's up to you.

David
 

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I would vote for keeping the EGR also, and 24s will be fine with I would run the Exploder 60mm throttle body with the mustang throttle arm if you are running an AOD and a lightning MAF
 

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I would suggest simply using a setup for 24# injectors, including the 65mm throttle body and 70mm MAF (your current one is 55mm). As the pinout on MAFs changed in 1996, stay with pre-'96 to match your early wiring. This would be as simple as using the stated setup from a 94-95 Mustang HO, or a 92-95 Crown Vic/Grand Marquis or Town Car. The nice thing is the last set are common and cheap at the wreckers. Hit the local 'yard and pull the MAF, TB and injectors, and go make your power.

The injectors are also common in E/F-250/350 vans and trucks, and there are lots of articles online about changing the throttle arm to use the Explorer throttle body on other 5.0 engines. If you want a bigger MAF, the Lightning ones are pricey, but the Lincoln Mk version is cheap. ;) Many options without going to expensive aftermarket, but that's up to you. In any case, you will need to re-tune.

David
 

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Discussion Starter #7
Thanks for the input.
Some years ago I blocked off the EGR on my Olds 5.7D, then on my 6.2D Chevy PU and then my BMW diesel powered Lincoln Continental. All without issues and a much cleaner intake. Then I blocked off the EGR on my daughters Duster w/318. That ruined that car, I melted the pistons in two engines before I figured out what the problem was.
With all that said you understand why I was concerned about the 5.0. Where the carbureted engine went very lean I understood the injected engine would adjust.
Was looking for more info and you supplied it, thanks.
 

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I misunderstood you question. Then, yes, you can block EGR on the 5.0L without damage (if you don't get cruise detonation that can break or crack piston rings), but you will see some negative impact to your mileage and efficiency. EGR does not affect idle, nor higher-throttle (75%+) power production. Properly functioning EGR is a good thing, but not necessary to the system to run OK.

David
 
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