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At what rpm does a Cobra become a Cobra

  • Thread starter Thread starter Jones331
  • Start date Start date Mar 30, 2005
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Jones331

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#1
  • Mar 30, 2005
  • #1
I was flamed pretty hard for asking this question. Got called everything from a rookie to a looser for it. I read somewhere that the second exaust valve's in the Cobra opened up at a certain rpm,I obviously recalled the artical wrong and you guy's thought I was trying to say the Cobra had some kind of V-tec in it. Well for my own sanity and SOME of my respect back I would like to clarify what I was asking. After digging up the artical I read, it was talking about the "IMRC" and how that changes at certain rpm's on the Cobra's it came equipt with. SO for all you hater's out there (AND you supposed geniuses) at what rpm does the IMRC start to change? Thanks............jj
 
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YtnGT

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#2
  • Mar 30, 2005
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It has something to do with the intake runners going from long to shorter at a certain rpm, I thought???

My friends 01 cobra (wife's car) really comes alive at approx 4000 rpms. I always figured that was when the intake runner thing happened.

It is neat, the cobra almost feels like you hit a 50 shot at 4000 rpms +.
 

Beau

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#3
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VTECH!
 

Gunfighter

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#4
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is it the same RPMs for each model year? i know they changed heads in '03 (?), but then again the blower will also have some effect, too
 
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YtnGT

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Gunfighter said:
is it the same RPMs for each model year? i know they changed heads in '03 (?), but then again the blower will also have some effect, too
Click to expand...

I think the intake thing is only for 96-01 cobras the 03-04 SCd cobra is different.
 

Jones331

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#6
  • Mar 30, 2005
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YtnGT said:
I think the intake thing is only for 96-01 cobras the 03-04 SCd cobra is different.
Click to expand...


True I am 99% sure that it is only through 01 model year..............jj
 

DBMSTNG

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the exhaust valves are controlled by the cams. the open up at every RPM. i think you are refering to the intakes with butterfly valves in the runners that restric flow at lower RPMs. i'm not positive, but i don't think any of the 4V's came with that setup from the factory.
 

white99gt

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#8
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Actually the IRMC (secondary openings) where only on 96-98 cars.(power started about 3500

The 99 and 01 cars had a redesigned manifold that did NOT have them.
The 03/04 have blowers and their power is felt instantly.
 

Dan02gt

mazing how much gas smell came from that tiny hole
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#9
  • Mar 30, 2005
  • #9
Jones331,

'96-'98 Cobras had the IMRCs, it is a butterfly that closes off 1 of the intake ports per cylinder. The IMRCs set between the intake and heads. This improves air velocity at low RPMs and thus improves low end performance. I think they open to allow flow through the secondary intake ports at ~3200 RPMs. Some people use IMRC deletes to remove these in an attempt to improve top end performance, the result of this is mostly just loss in low end torque on a motor that already sucks on the low end.

Dan
 

Jones331

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#10
  • Mar 30, 2005
  • #10
white99gt said:
Actually the IRMC (secondary openings) where only on 96-98 cars.(power started about 3500

The 99 and 01 cars had a redesigned manifold that did NOT have them.
The 03/04 have blowers and their power is felt instantly.
Click to expand...

Yea maybe youre right,but doesn't Ford offer it in the fr500? and out of their catolog? Just a thought.......jj
 

white99gt

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#11
  • Mar 30, 2005
  • #11
Jones331 said:
Yea maybe youre right,but doesn't Ford offer it in the fr500? and out of their catolog? Just a thought.......jj
Click to expand...

Ford doesnt offer what?
 

stangman

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#12
  • Mar 30, 2005
  • #12
white99gt said:
Ford doesnt offer what?
Click to expand...



the imrc style intake manifold, i would assume
 

Jones331

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#13
  • Mar 30, 2005
  • #13
white99gt said:
Ford doesnt offer what?
Click to expand...
No. Doesnt Ford offer it (imrc) or (butterfly's in the runners) on the fr500 and out of their catolog?........jj
 

roti

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#14
  • Mar 30, 2005
  • #14
Jones331 said:
I was flamed pretty hard for asking this question. Got called everything from a rookie to a looser for it. I read somewhere that the second exaust valve's in the Cobra opened up at a certain rpm,I obviously recalled the artical wrong and you guy's thought I was trying to say the Cobra had some kind of V-tec in it. Well for my own sanity and SOME of my respect back I would like to clarify what I was asking. After digging up the artical I read, it was talking about the "IMRC" and how that changes at certain rpm's on the Cobra's it came equipt with. SO for all you hater's out there (AND you supposed geniuses) at what rpm does the IMRC start to change? Thanks............jj
Click to expand...

Oh, ya big wuss. Let's be pals. Let's let by-gones be by-gones... Okay?

Group hug for the weenie.

But to let you know, a Cobra becomes a Cobra when it hit's 8 inches.

Queastion asked, answer supplied.

 

white99gt

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#15
  • Mar 30, 2005
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Jones331 said:
No. doesnt Ford offer it (imrc) or (butterfly's in the runners) on the fr500 and out of their catolog?........jj
Click to expand...

Of course its not offeed on the fr500, it uses a intake similar to the 99up cobras. And a IMRC intake is not offered because it was nothing but headaches when it got carboned up.
 

Jones331

Banned
Oct 2, 2004
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Mar 30, 2005
#16
  • Mar 30, 2005
  • #16
roti said:
Oh, ya big wuss. Let's be pals. Let's let by-gones be by-gones... Okay?

Group hug for the weenie.

But to let you know, a Cobra becomes a Cobra when it hit's 8 inches.

Queastion asked, answer supplied.

Click to expand...


Anwser recived,comebacks brewing...........jj
 

Jones331

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#17
  • Mar 30, 2005
  • #17
Then what IS Steeda talking about? (below is off their web site?)...........jj

Ford Racing FR500 variable geometry intake



Ford Racing FR500 variable geometry intake
$2795.00



Ford Racing FR500 Intake for use on 99/01 Cobras with stock heads or 96-98 Cobras with FRPP Heads. Kit comes with injectors, MAF, and Processor. Variable runner length for improved low end power and top end power.
© 2002 STEEDA AUTOSPORTS INC. All Rights Reserved. 1351 NW Steeda Way Pompano Beach, Florida 33069
 

white99gt

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Mar 30, 2005
#18
  • Mar 30, 2005
  • #18
Jones331 said:
Then what IS Steeda talking about? (below is off their web site?)...........jj
Click to expand...

Its similar to a 99 up intake but it also has butterflys except they are cable controlled.

View attachment 518704


BUT it was a prototype car and very few peaple will ever use that intake on a street car..SO what does it have to do with what rpm a cobra becomes a cobra?
 

Jones331

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#19
  • Mar 30, 2005
  • #19
[

..SO what does it have to do with what rpm a cobra becomes a cobra?[/QUOTE]


You tell me? I wanted to know at what rpm did they open up?Not trying to kick a dead horse just have some honest questions..............jj
 

Jones331

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#20
  • Mar 30, 2005
  • #20
[

BUT it was a prototype car and very few peaple will ever use that intake on a street car


So why would someone use it on a race car if all it does is promote low end power/or torque?,,,,,,,,,,jj
 
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