Building a 331 Computer and tuning questions

J

JS94cobra

Banned

Mar 8, 2006

58

0

0

NJ

Jun 16, 2006

#1

• Jun 16, 2006

• #1

I have a 94 cobra and am building a 331 stroker for it. eagle crank, rods, probe pistons, windsor sr heads ported cobra intake and an emission legal cam(not sure which one yet). I am curious on what this combo will do to my stock computer? Will I need to do get an aftermarket computer? any advise help would be great! Thanks

 

95strokerPSU

Member

Jul 29, 2004

986

1

19

Sacramento from Philly

Jun 16, 2006

#2

• Jun 16, 2006

• #2

Depending on the cam, you'll most likely have some idle surge and bucking issues. I think the general consensus on this site is to keep the stock computer and either get a self tuner or take it and get dyno tuned. Over on Corral they're still debating on whether or not swapping out to a 93' A9L is still beneficial. I'd recommend keeping the stock computer and limping the car right over to a shop and gettin an SCT tune. Just my $.02.

Dave

 

J

JS94cobra

Banned

Mar 8, 2006

58

0

0

NJ

Jun 16, 2006

#3

• Jun 16, 2006

• #3

95strokerPSU said:

Depending on the cam, you'll most likely have some idle surge and bucking issues. I think the general consensus on this site is to keep the stock computer and either get a self tuner or take it and get dyno tuned. Over on Corral they're still debating on whether or not swapping out to a 93' A9L is still beneficial. I'd recommend keeping the stock computer and limping the car right over to a shop and gettin an SCT tune. Just my $.02.

Dave

Click to expand...

Thanks Dave. My setup is looking very similar to yours. When you built yours did you use a girdle? The only thing right now that I am debating on is my compression ratio. What is your CR if you don't mind me asking. I would like a CR close to but below 10:1. I am looking for around 300-350 rwhp but a blower running 8 psi would be great too boosting that number.

 

blksn955.o

Founding Member

Mar 15, 2002

3,263

0

66

st.louis mo 314

Jun 16, 2006

#4

• Jun 16, 2006

• #4

A good 331 shoule make the hp goal preaty easy. There are good 302 H/C/I setups running in that range.

As far as the toooon would go, in the tweecer/other tuner/dyno tune the biggie with the larger motor is going to be getting your load set up proper so the eec will calc. that load correctly. That and getting your maf/inj. slopes/breakpoint/offsets correct for the maf and inj. (the maf does not tune for the inj. it is done in the eec in a seperate area).

 

95strokerPSU

Member

Jul 29, 2004

986

1

19

Sacramento from Philly

Jun 16, 2006

#5

• Jun 16, 2006

• #5

I'm at 10.5:1 CR with the Edelbrock heads. Obviously if you're planning for boost down the line you'll want a lower CR. The heads are a little small for the added cubes and the intake is a little too restrictive on the top end. But it makes good power at low RPMs which I like for a 99% street car. I'm considering getting some work done to the heads and a custom cam next winter, or just a ZEX kit. Not sure, but good luck with your build and ask questions cause there's a lot of guys on here that know a lot about these cars.

Dave

 

final5-0

Mustang Master

Apr 6, 2003

6,817

12

79

DFW Texas

Jun 16, 2006

#6

• Jun 16, 2006

• #6

I can't see or think of any reason to not to use the pcm you now got.

You tune it or have a Pro tune it and all will be good to go.

I'd go 347 but that has nothing to do with your tune Q.

Grady