4V heads and Turbos. Opinons wanted.

[chagan02]

Hey guy's. Need some opinions. I'm going to do a 4v swap in my car in the next year. I recently bought an engine from a 96 lincoln. So I have the B heads. After buying, I'm having second thoughts about them. Seems my only intake option is the 96-98 Cobra intake, which I dont like as much as the 99-01 Cobra intake. Also, I know after doing some reading the tunnel port C heads are better. So here is my question. I already have a forged shortblock that I'm running now with a 2V setup. Car is making just over 500 at the wheel, HP and TQ on 17 PSI. MY plan is to switch to 4V, port the heads, and get a set of turbo cams as I want to go turbo instead of SC.

So, What would you guy's do? Sell the B heads, save and get a set of C heads and get a 99-01 Cobra intake? Keep the B heads and just get the 96-98 Cobra intake?

My goal is around 700-750 at the wheel with a 76mm turbo setup running around 18-20 PSI.

My other option for the Power adder is to use the 4V setup with my Novi 2000, which is maxed out now (max impeller rpm) at around 17 PSI. I just dont know what kind of power levels I would hit with that. Plus I know the torque curve with the Turbos would be much better.

What do you guy's think?

 

[Driver500]

You can make that with ported 2v PI heads without the 4v swap. I wouldnt run that much boost on either 2v or 4v on 93 octane though. At least use a methanol setup if you don't want to reserve your higher boost setting for race fuel.

You'll make around 700 with ported heads on a 2v at about 19-20 lbs.

 

[whtcobra1998]

b heads are better for boost, just depends on what you want. i think the b head intake looks better than the c head intake, I would love c heads for street but with a b head upper grafted on. I make 555 rwhp on 16 psi with a greddy t88 through an auto, on 91 psi, so motor is close to 700hp on pump gas

 

[chagan02]

through an auto, on 91 psi, so motor is close to 700hp on pump gas

Holy Boost Batman! LOL.

b heads are better for boost, just depends on what you want. i think the b head intake looks better than the c head intake, I would love c heads for street but with a b head upper grafted on. I make 555 rwhp on 16 psi with a greddy t88 through an auto, on 91 psi, so motor is close to 700hp on pump gas

So I take it you are running B heads and the 96-98 Cobra intake? Are you using IMRC deletes? I take it that auto really pulls the RWHP down. You are running about 1lb less boost than I, making about 10 more rwhp, BUT, you are running that through an auto. Pretty impressive. How is the torque? I'm sure it's awesome with the turbo. When does you car start to spool, and when does it hit max boost if you dont mind me asking?

 

[32vApe]

With the option of the trickflow heads why even do a 4v swap. And like stated above you can make 700 with ported pi heads, cams, and a turbo. Also, there is an issue somewhere if your pullied for max impeller rpm on a novi 2000 and are only seeing 17 psi on a 2v. That should be north of 25 psi . Belt slip maybe?

 

[Brutal Metal]

I'd only consider the 99-01 heads if you could get them complete at a very good price.
If going the C head route 9 thread 05 Revisions!

 

[encasedmetal]

C heads= better N/A
B heads= better boost

if you have a 4v running 20psi and you are only making 700rwhp there's something wrong.

 

[1QUICK10TH]

Also, there is an issue somewhere if your pullied for max impeller rpm on a novi 2000 and are only seeing 17 psi on a 2v. That should be north of 25 psi . Belt slip maybe?[/QUOTE
:thumbsup:

 

[Fast?notyet]

in my opinion if you are looking for higher hp numbers and u r going to want to make it higher in the rpms go with a set of 4v heads which ones u use doesn't matter so much because both do well when ported as far as boost goes from what i've seen. However the 2v heads will get you there, like if u use the TFS heads it will probably make more power lower in the rpm's cause it won't flow quite as good. They will flow good but not as good because of the surface area of the valves in a 4v set up that is why everyone has gone to 4v's in most cars on the road today it is inherently better to start with. Cams would help the 2v get that high and the 2v sound nasty with 550 lift and beyond cams so it is going to be a matter of choice. And like always it depends on your budget. Also telling us you r going to us a 76mm doesn't give enough info what is the exhaust A/r going to be?

 

[Fast?notyet]

C heads= better N/A
B heads= better boost

if you have a 4v running 20psi and you are only making 700rwhp there's something wrong.

Did you get that from the seat of your pants? lol

 

[chagan02]

With the option of the trickflow heads why even do a 4v swap. And like stated above you can make 700 with ported pi heads, cams, and a turbo. Also, there is an issue somewhere if your pullied for max impeller rpm on a novi 2000 and are only seeing 17 psi on a 2v. That should be north of 25 psi . Belt slip maybe?

I was thinking that too, however, doing the math it seems that its about maxxed out on its rpms. I have a 2.7 inch blower pulley on it now.

Stock Crank Pulley Diameter 6.5":

6.5/ 2.7 = 2.40 overdrive ratio

6000 X 2.40= 14400
6500x2.40 = 15600
7000x2.40= 16800

It looks like the max rpm is 55000 on paxtons website, and I think they have a 3.61 internal step up ratio. If by max rpm they mean impeller speed.

Shifting at 6K
14400 X 3.61 = 51984

Shifting at 6.5K
15600 X 3.61 = 56316

So by that standard, I cannot go with an overdrive pulley on the crank. I could be wrong in my calculations too, I'm not sure. I'm positive the car is losing no boost. Maybe a good set of Trick Flow heads would just do the trick. The Car already has Crower stage 2 Blower cams in them:
Dur @ .050” Lift: 216°/216° RR: 1.8/1.8 Gross Lift: .581”/.581” LSA: 114° RPM: 1500 to 6500 Redline: 6500

 

[32vApe]

Wow, a 2.7 blower pulley? Yes your math is correct on calculated impeller speed. I have seen a built 4.6 2v with ported pi heads, 230 @.050" .550" lift cams, make mid 700's rwhp with a 2.9" blower pulley and a 7.5" crank pulley making 25psi at 7k. Yes that is over spinning it but it worked. Sounds like the rest of the combo is done well. The trick flow heads will be worth around 80 whp on your setup.

 

[Brutal Metal]

Also, there is an issue somewhere if your pullied for max impeller rpm on a novi 2000 and are only seeing 17 psi on a 2v. That should be north of 25 psi . Belt slip maybe?[/QUOTE
:thumbsup:

a Novi 2000 supporting north of 25psi?:shrug: show me ONE Dyno graph!

 

[chagan02]

So, it looks like the power adder is about maxed out. Seems like the collective opinion here is that Trick Flow heads would really improve my setup. Does anyone know what the flow rates of the Trick Flow compared to Stock and Ported 4v B Heads?

 

[chagan02]

in my opinion if you are looking for higher hp numbers and u r going to want to make it higher in the rpms go with a set of 4v heads which ones u use doesn't matter so much because both do well when ported as far as boost goes from what i've seen. However the 2v heads will get you there, like if u use the TFS heads it will probably make more power lower in the rpm's cause it won't flow quite as good. They will flow good but not as good because of the surface area of the valves in a 4v set up that is why everyone has gone to 4v's in most cars on the road today it is inherently better to start with. Cams would help the 2v get that high and the 2v sound nasty with 550 lift and beyond cams so it is going to be a matter of choice. And like always it depends on your budget. Also telling us you r going to us a 76mm doesn't give enough info what is the exhaust A/r going to be?

I'm looking for a safe A/F ratio of around 11.8 to 12.5. Obviously budget is a concern. I could however, for about the same cost as the TFS heads, have my 4V B heads ported/valve job, buy some 03 Cobra Cams, and the rest of the stuff needed to covert to 4V. Then I would have more potential with the 4V setup and could upgrade the cams later on. Maybe I'm wrong. Those dang TFS heads are $2000+ new. I just need to investigate what all I would need further. I do have the cams already for the 2V heads though, and they sound great. My goal is to get the car in the low 10s - high 9's consistently. Rear end is built, going with a an auto, and all Team z suspension front and rear.

 

[98 Saleen Cobra]

Safe AFR is like 11.5 not 12.5, if you do some B-heads get 98 Cobra cams not 04.. Or the TFS heads.

 

[chagan02]

Safe AFR is like 11.5 not 12.5, if you do some B-heads get 98 Cobra cams not 04.. Or the TFS heads.

Thanks for the advice. Yeah thats what I meant on the A/F. LOL. Been like 3 years since I have had my car tuned, I thought it was safe at like 11.8. Now that you point it out, I remember, anything over 12 was not good. So 11.5 would be better. Thanks again. Why the 98 Cobra cams on a boosted engine over the 03 cobra cams? Is it because I'm speaking of switching to turbo and the NA cams would be better for that than the cams out of the termi?

 

[whtcobra1998]

Holy Boost Batman! LOL.




So I take it you are running B heads and the 96-98 Cobra intake? Are you using IMRC deletes? I take it that auto really pulls the RWHP down. You are running about 1lb less boost than I, making about 10 more rwhp, BUT, you are running that through an auto. Pretty impressive. How is the torque? I'm sure it's awesome with the turbo. When does you car start to spool, and when does it hit max boost if you dont mind me asking?

stock intake, imrc deletes, cleaned up heads with cams. it hits full boost @4k, shift towards 8k rpm with 3.27 gears, It will light my street tires up at 100mph no problem. 4v is the way to go.

 

[03TRKB]

I would port the B Heads and have it short runnered. Or you could learn to to TIG aluminum and make a Sheetmetal Intake, I believe MMR offers one.