Engine GT5.0 Intake vs. Edelbrock Performer RPM

Willybill32

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Jul 16, 2019
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Hi together, I am new to this great place. I am from Germany and driving a 86GT and 69Mach1.

Currently I am thinking about changing from the original EFI intake to an Edelbrock Performer RPM. But I am not quite sure what the result will be.

My setup:

- Stock cam
- GT40 heads
- Stock intake
- 75 throttle
- PowerTrax No Slip Traction System
- Ring Gear 3,27:1
- T5 gearbox
- Centerforce clutch
- 24lbs injectors
- NO MAF

I am really interested in your opinion in which sections the RMP might be better. Car is mainly driven in street, but you know, from time you want to kick it as hell ;)

Looking forward to your ideas.
Best
Felix


IMG_8342.jpg
Wow, that engine and engine compartment is beautiful! I’m envious! My ‘86 has the Edelbrock Performer intake, Trick Flow heads, roller rockers and Bassani ceramic coated headers, but doesn’t look nearly as good!
 

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tmoss

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Well, you bought an Explorer and that will work well in stock condition. If you ported your stock HO lower, left the upper stock and ran a 65mm TB on it it would flow almost exactly what the GT40 heads flow. I'm sure you could find someone in Germany to port your lower - only question is cost. Then you could keep that beautiful HO upper. Here is a link to my page that has an article porting the HO lower "Porting a stock lower intake". Good luck, either way you go....... http://tmoss.efidynotuning.com/?q=user
 
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7991LXnSHO

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Well, you bought an Explorer and that will work well in stock condition. If you ported your stock HO lower, left the upper stock and ran a 65mm TB on it it would flow almost exactly what the GT40 heads flow. I'm sure you could find someone in Germany to port your lower - only question is cost. Then you could keep that beautiful HO upper. Here is a link to my page that has an article porting the HO lower "Porting a stock lower intake". Good luck, either way you go....... http://tmoss.efidynotuning.com/?q=user
Hoping for a good idea is why I tagged you. Thanks.
What do you think porting the stock upper does for flow? I have one matched to a 70mm TB snd EGR, then opened the intake throat back as far as the tools will go and as straight as possible without breaking into the bolt holes. The PO had already ported the lower and exit half of the upper intake. The SOP meter said it was a good idea, but I have no flow bench access.
 

tmoss

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Hoping for a good idea is why I tagged you. Thanks.
What do you think porting the stock upper does for flow? I have one matched to a 70mm TB snd EGR, then opened the intake throat back as far as the tools will go and as straight as possible without breaking into the bolt holes. The PO had already ported the lower and exit half of the upper intake. The SOP meter said it was a good idea, but I have no flow bench access.
The stock upper has a 63-64mm TB opening, so you can run a 65mm TB on it and have a .5-1mm ring around the edge - not enough to affect flow or power and is a no-work work mod. My page also has an article on porting the upper as well. Porting the upper will help lift the rpm band some but not a lot with stock GT40 heads as they tend to flow best in the mid lift area. Porting the upper is hard to get a increase in flow on a bench because flow is static and we flow them together, not separate - that is dumb - not how an engine uses an intake. The biggest gain to be had in flow is always the lower for a HO or GT40 family intake. The GT40 intakes are most often 69mm that we have seen. The more a head flows, the more reason to port an upper in either of those intakes. For the GT40 family we encourage it at about 260cfm or higher, but other factors about the build will affect that.
 
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Fox86

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Well, you bought an Explorer and that will work well in stock condition. If you ported your stock HO lower, left the upper stock and ran a 65mm TB on it it would flow almost exactly what the GT40 heads flow. I'm sure you could find someone in Germany to port your lower - only question is cost. Then you could keep that beautiful HO upper. Here is a link to my page that has an article porting the HO lower "Porting a stock lower intake". Good luck, either way you go....... http://tmoss.efidynotuning.com/?q=user
Thanks for your input! I recently read in one of the Fox Performance books that it is possible to port the stock intake, but that you really need to know what you are doing- especially on the stock one. Else you will not have any Benefits. For now I will put the explorer intake on the Fox, maybe I will do the same with the upper like the previous owner. He did the whole intake by hand.

@tmoss does it make sense to port the explorer lower?

Thanks everybody for taking part in conversation! Nice place here
 

Fox86

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Wow, that engine and engine compartment is beautiful! I’m envious! My ‘86 has the Edelbrock Performer intake, Trick Flow heads, roller rockers and Bassani ceramic coated headers, but doesn’t look nearly as good!
Thanks a lot! Mine might look nicer, but you have more power :)
hallo Felix .. bohh super clean !! sehr schoen...... wie alle schreiben .. Torque geht verloren in den unteren und mittleren Drehzahlen dafuer oben raus mehr .. ich hatte so ein teil drauf als ich meinen 92 bekam ..habe dann aber den Intake verkauft und ein original Tubular mit bearbeiteten kanaelen montiert ..der unterschied ist schon markant.. viel mehr Power in den mittleren drehzahlen ..und halt oben raus wird er ein bisschen lahm weil eben die Kanaele zu klein sind und einfach die Luft fehlt...da helfen dann auch die Nockenwelle und die AluKoepfe nicht mehr weiter ..die Bremse sind die kleinen Kanaele im unteren Ansaug ..schlimmer noch mit dem Stroker motor.. aber wenn du keine Rennen faehrst oder so ... alles nicht so schlimm...wenn du mehr Sprint willst .. dann besser ne andere uebersetzung 3.73 oder so .......
hey Grüße nach Costa Rica Bist du da auch mit einem Fox unterwegs? Danke für deine Meinung. Stimmt, an der Übersetzung kann man auch noch feilen:)
 

marcelo

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Thanks a lot! Mine might look nicer, but you have more power :)

hey Grüße nach Costa Rica Bist du da auch mit einem Fox unterwegs? Danke für deine Meinung. Stimmt, an der Übersetzung kann man auch noch feilen:)
jaja ...92 hatchback ....331 stroker ..aber mehr spielzeug und zeitvertreib .fahre nich sehr viel ..ein bisschen Drag race und Strassenrennen ....kann man hier noch gut machen ..nicht soviel Bolizei unterwegs...
 

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tmoss

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@tmoss does it make sense to port the explorer lower?
The stock Explorer flows ~205cfm average and your heads flow mid-190cfm so no real need - BUT You could port just the two front runners short side radius per my instruction article to even out flow distribution. Since the heads are the restriction it might not result in a noticeable gain.
 

7991LXnSHO

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No fair speak'n deutsche, can't tell what you're say'n about white rednecks and all. :jester:
And despite part of my heritage, German is a third language for me. I could pronounce it well enough or sing an Art or Rock Song from a German text, but comprehension is just under 50%. You might get a kick out of how Google translate does. It has done Mandarin well enough for certain eBay and Amazon sales. I always wondered how silly it sounded, but the sellers did not complain at the attempt and I got what I tried to order.
The quote translation starts here.
“hello Felix .. bohh super clean !! very nice ...... as everyone writes .. Torque is lost in the lower and middle speeds but more at the top .. I had such a part on it when I got my 92 .. but then sold the intake and an original Tubular mounted with machined channels .. the difference is already striking .. a lot more power in the middle speeds .. and stop at the top it gets a bit lame because the channels are too small and simply the air is missing ... then help also the camshaft and the aluminum heads no longer .. the brakes are the small channels in the lower intake .. worse with the stroker motor .. but if you are not racing or something ... not that bad ... if you want more sprint .. then better ne another translation 3.73 or so.”
So Google’s A.I. is not ready to take over the world and completely reset the economy yet in 2020. That will have to be on the list for another eventful year. We still have time to enjoy our rides.:burnout:
 
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General karthief

wonder how much it would cost to ship you a pair
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And despite part of my heritage, German is a third language for me. I could pronounce it well enough or sing an Art or Rock Song from a German text, but comprehension is just under 50%. You might get a kick out of how Google translate does. It has done Mandarin well enough for certain eBay and Amazon sales. I always wondered how silly it sounded, but the sellers did not complain at the attempt and I got what I tried to order.
The quote translation starts here.
“hello Felix .. bohh super clean !! very nice ...... as everyone writes .. Torque is lost in the lower and middle speeds but more at the top .. I had such a part on it when I got my 92 .. but then sold the intake and an original Tubular mounted with machined channels .. the difference is already striking .. a lot more power in the middle speeds .. and stop at the top it gets a bit lame because the channels are too small and simply the air is missing ... then help also the camshaft and the aluminum heads no longer .. the brakes are the small channels in the lower intake .. worse with the stroker motor .. but if you are not racing or something ... not that bad ... if you want more sprint .. then better ne another translation 3.73 or so.”
So Google’s A.I. is not ready to take over the world and completely reset the economy yet in 2020. That will have to be on the list for another eventful year. We still have time to enjoy our rides.:burnout:
I agree with the need to match air flow, efi suffers from the same 'bigger is not better' problem as when we were using carburetors.
And I won't tell anybody about what was said about rednecks :rolleyes:
 

tmoss

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which intake is better depends on the whole car build. I ported an rpm1 intake for a blown 331 race car and it flow tested 277 cfm average (we have ported then to flow 313 cfm) when I was done. It went on AFR 205 308 cfm heads. He tried a Box-R intake to go faster but couldn't and when he took that off and put the rpm1 back on he went quicker and faster than ever. There is one primary reason for this - let's see who can guess why.
 

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General karthief

wonder how much it would cost to ship you a pair
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I'll guess again and say because of the engine working rpm, volume and velocity needed to fill the cylinders, in this case size matters?
 

tmoss

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The Power glide 2 speed transmission. He made more peak power with the Box-R but lost average power. He needed his torque curve to be FAT in the one shift range for shift recovery and hang in therethrough his stated shift point. The torque (average hp) lost was too great with the Box-R to match the "smaller" intake. If he had a 6-8 speed auto things might have been different.
 

General karthief

wonder how much it would cost to ship you a pair
Mod Dude
Aug 25, 2016
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In my defence, I did not have enough info to give an inexperienced answer.
So do I win anyway?
You know in todays world everybody is a winner.
 
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Fox86

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Hi together,

again a question concerning upgrading my fox :) The next weeks the Explorer upper and lower will arrive - the whole setup of my car you´ll find in the beginning of this thread.

Right now I have the chance to get some additional parts to get some extra power. I have the possibility to get a X3Z from a 93 Cobra including corresponding 70mm MAF and flow matched injectors. Additionally on top 1.7 roller rocker arms. So the configuration comes a bit more into direction of Cobra engine and I hope to get some additional power.

What´s your opinion about it?

Is the switch to the X3Z same like to A9L? I found on lmr.com a description about how to change the wiring when using another PCM (How To Install Fox Body Mustang Mass Air Conversion (86-88) (lmr.com) but I am not sure if this same with X3Z. Maybe somebody has a description, I didn´t find one...

Additionally I have a 75mm throttle body - should I switch to a smaller when I have a 70 mm MAF?

Thanks a lot for your help and advice.
 
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