I want proof that head porting is NOT worth it!!!

[DSG2003SVT]

Not trying to sound like a punk by the title, but every time that I ask this question, I just get a flood of "NOPE, NOT ON A POSITIVE DISPLACEMENT BLOWER CAR, NO WAY!! First off, I know you will most likely lose boost and retain the same power, but if you have a twinscrew or turbo, you can safely gain that boost back again. I want to do many things to my car and I'm not convinced that head porting would be a waste in my case. I want to do a twinscrew and LTs, I already have crower stage 3 blower cams, and when this shortblock gives up, I'll go with a VT 302, 304, or 324. Anyone that has any dynos or write ups on ACTUAL 03-04s with this done to them, please post up. If you don't have proof supporting that it is not worth doing, please don't tell me what I've already heard 1000Xs. The reason that I'm asking this is that Stiegemeier just recently started 03-04 Cobra head porting and he's got me curious. Here's his breakdown on stage 1, 2, and 3 head porting for our cars:

All stages have bronze guide liners.

Stage I:
Custom Stiegemeier valve work 46 degree radius.
All maching done on a Serdi 100
CBN surfacing bowl blend and deburing
Precision assembly with new seals
about 25hp

Stage II:
All above plus
Max Exhaust Porting
Intake Blue Printing
about 40hp

Stage III:
All above plus
Max Intake Porting and Chamber Polishing
about 50hp

Now granted, you may not be able to bolt them straight on and see gains, but if you repulley the blower or turn up the boost on the turbo to make up for what boost you loose...what then?

 

[CobraBob]

Make it easy. If you believe head porting is a plus for the Terminator then go ahead and do it. Then you can report the results to us. Might be some interested in those results. ;-)

 

[slo-poc]

I'm also very interested in these results.....??????

 

[DSG2003SVT]

Make it easy. If you believe head porting is a plus for the Terminator then got ahead and do it. Then you can report the results to us. Might be some interested in those results.

I'm seriously considering it, . I want to buy the jan 05 heads and I figured I would look into improving them while they were off of the car. I'm going to have to change my cams, springs, and retainers when I do, so it's going to be a lot of work. May as well get them worked over to get the most out of my car.

 

[Mustang2Saleen]

Not trying to sound like a punk by the title, but every time that I ask this question, I just get a flood of "NOPE, NOT ON A POSITIVE DISPLACEMENT BLOWER CAR, NO WAY!! First off, I know you will most likely lose boost and retain the same power, but if you have a twinscrew or turbo, you can safely gain that boost back again. I want to do many things to my car and I'm not convinced that head porting would be a waste in my case. I want to do a twinscrew and LTs, I already have crower stage 3 blower cams, and when this shortblock gives up, I'll go with a VT 302, 304, or 324. Anyone that has any dynos or write ups on ACTUAL 03-04s with this done to them, please post up. If you don't have proof supporting that it is not worth doing, please don't tell me what I've already heard 1000Xs. The reason that I'm asking this is that Stiegemeier just recently started 03-04 Cobra head porting and he's got me curious. Here's his breakdown on stage 1, 2, and 3 head porting for our cars:

All stages have bronze guide liners.

Stage I:
Custom Stiegemeier valve work 46 degree radius.
All maching done on a Serdi 100
CBN surfacing bowl blend and deburing
Precision assembly with new seals
about 25hp

Stage II:
All above plus
Max Exhaust Porting
Intake Blue Printing
about 40hp

Stage III:
All above plus
Max Intake Porting and Chamber Polishing
about 50hp

Now granted, you may not be able to bolt them straight on and see gains, but if you repulley the blower or turn up the boost on the turbo to make up for what boost you loose...what then?

I too am interested in seeing what kind of gains you can get out of head porting. By the way boost does not create HP, its the displacement of air. 15lbs of boost on a T88 Turbo will create more HP than 15lbs of boost on a T3 Turbo. Its all about the displacement of air. So will you have to change the cams/spings/retainers when the port is done?

 

[DSG2003SVT]

I realize that losing boost does not neccessarily mean losing power, what I was saying is that people say that you will lose boost but maintain the same power level as before. That's a good thing, means more efficiency, but if you pulley down the supercharger so that you make the same amount of boost as before, then you have in fact gained power from porting your heads. As far as cams, springs, and retainers, I'm sure that this would help with ported heads and I already have changed them. Yet another reason why I'm trying so hard to figure this out before taking the plunge. Let's say you gain 25rwhp from heads and cams, but lose 2lbs of boost. Boost is worth about 13-26 hp depending on the application, if you bring your boost up to what it was before, then you have actually gained at least 13+13+25 hp from the heads/cams. That equals 51 by the way, LOL. Had my calculator handy so I decided to go ahead and figure that for everyone.

 

[Jimmysidecarr]

If I had the occasion to take my heads off... The first thing I would do is get better guides and a pro quality endurance racing type valve job. The wider margins on the exhaust valves and seats pulls more heat out of the chamber and suppresses detonation.

The better cylinder sealing will show a little more power even without porting.
Stiegemeier is a PRO!!! Tell him what you want and he will be able to deliver it!

It's the actual porting that has limited gains... there are still GAINS though!!! A lot of it will be from the blending in the bowl, minor clean up in the port and the valve job itself.

Racers know the value of a fresh valve job... and now more and more people are finding out as well.

DO IT!!!:rockon:

 

[IronTerp]

Well, from what I've heard, the big knock on porting the 4v 03/04 heads is not necessarily that it's worthless on our applications, but rather that it's bang for the buck quotient is not very high. Now, if Steig is advertising 25, 40, and 50 RWHP gains from his porting, then I think a ton of folks would sit up and start listening.

We've had two Terminators in the MACA who ran ported heads and both were mid 10.5 to 10.7 second Cobras. Each had high boost twin screws and were loaded with go-fast goodies.

Now for what's it's worth, these same two folks are racing two entirely different Cobras, with factory heads, and both are still running mid 10's.....I agree with CB: We need some guinea pigs!!!!!

 

[redsvtcobra]

Stiegemeier is definitely a pro. Like it was said though, pulling off the heads and replacing them after a port is quite a job. Is the cost and time worth 50hp total? To some hell ya! Go for it.

 

[FaYgOkRiS]

What r the prices on those stages???

 

[DSG2003SVT]

My dilema now is which port to go with, stage 2 or 3. The stage 2 would probably produce more low end TQ because the intake ports wouldn't be ported like the stage 3. Question is, would the top end gain be better than the low end loss. If not in my current setup, but if I do go with a VT 324 in the future, will that be enough displacement to take advantage of the stage 3. I will have a twinscrew and LTs for sure when I do a head swap, don't know about the new shortblock though. If I have a 324 and stage 3 heads with my stage 3 cams, will I need to go with a KB 2.6 like I have been planning, or would a 2.8 be better? Would it be better at pump gas safe boost range or only at higher boost? I'm so confused!! Somebody has to have some answers for me. haha

 

[droptopsnake01]

your boost will drop b/c your motor will be working more efficient and you will pick up more power also.

 

[DSG2003SVT]

What r the prices on those stages???

$1295, $1895, and $2895 respectively. He said he has cores as well if anyone wants to do a weekend swap.

 

[DSG2003SVT]

your boost will drop b/c your motor will be working more efficient and you will pick up more power also.

Exactly as I was explaining in post #6. You make more power with less boost, then you can add the boost back to make even more power still at a safe level.

 

[FaYgOkRiS]

Wow, with prices that stout why not consider just swapping with a set of fr500's??? I know steigi is the shit, but 3K for a stage 3 is a bit outta quite a few people price range. Just my .02

 

[DSG2003SVT]

Wow, with prices that stout why not consider just swapping with a set of fr500's??? I know steigi is the shit, but 3K for a stage 3 is a bit outta quite a few people price range. Just my .02

The thing is that the fr500 heads only barely outflow the stock 03-04 heads and the 03-04s out flow the fr500s if they're both ported.

 

[04cobracop]

3,000 dollar for maybe 50hp. UM NO NO NO NO!!!!!!!

 

[04cobracop]

3,000 dollars for maybe 50hp. UM NO NO NO NO!!!!!!!

 

[FaYgOkRiS]

Oh, well I didn't know that. SO I'm thinking they shoul have a sale like they did on there blowers, lol!

 

[DSG2003SVT]

Here's a link to the fr500 head vs. terminator head data. :thumbsup:
http://www.modularfords.com/forums/488737-post392.html