2v vs 4v forced induction

[smkn99]

So im going forced induction on my 99 gt and and debating on if going 4v would be worth it.

right now i have stage 3 patriot performance heads, stage 2 mhs blower cams, and 9.0:1 compression and am making 334rwhp on my 2v.

my question is that if my 2v heads that i have right now are better for boost than getting a set of c heads.

 

[2KBlackGT]

I don't care what opinions you get, stay 2V. There was a member here (Sinultros was his name i think) that had a 03/04 Cobra and a 2V GT, both had the KB2.8 on the and the 2V made more power. I'm not saying that's the norm or anything but my point is a built 2v will make comparable power.

 

[po-po 5.0]

If the numbers I've scrounged are accurate, a patriot stage III PI head flows about [email protected]" of lift on the intake. A 99/01 4v head is 231, and an 03+ is [email protected]" of lift.


So box stock, the 4v heads will outflow your current heads.

Granted, flow isn't everything, but its a fair indicator of peak power.

 

[01yellercobra]

What are your goals? There was a 2V around here making a hair over 600rwhp. That was with NPI heads that were worked within an inch of their life and custom cams. Boost was somewhere in the low 20's. So it can be done. Just takes a little more compared to a 4V.

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[coposrv]

I would stay 2v. If your short block is built especially. 2v can make great power. I think a big reason you don't see as many high power 2v builds is because when guys plan to spend a lot of money they don't want to think they left anything on the table by building what they may feel is an inferior engine.

 

[GoingHaam]

the point of forced induction is to force air into the engine. a 4v will allow you to force in more air than a 2v. 4v > 2v..... but that does not mean you cannot make the same or greater power than a 4v. you will just need more aggressive components.

 

[y2k2gt]

Last I read the 03 4v heads flow [email protected] lift, but the stock 03 4v intake cams only have a lift of .394.
Didnt the Mach 1's only make about 270-280rwhp with 10:1 compression?

 

[96GT/SC]

Ive seen 600whp with stock PI heads and 20lbs of boost. 2v can make power just fine. Im staying 2v because its rare and if your car is quick everyone assumes you have a 4v swap.

 

[triple-s]

I for one would just stay 2v you already have great heads why waste money if you don't need to. I'm on a forged 281 with stage 2 patriot heads,custom grind cams from bullet racing and a f1a on 20 pounds making 621 tuned thru Eric brooks. 2V's are great power markers.

 

[froush]

I wont give you numbers yet but im fully expecting 600+ with my setup at 18-20psi. These little 2vs can make plenty of power to put a smile on your face. There is a guy on modded with somewhere around the 800 mark and hes shooting for 1k out of a 2v. Thats with spray on top of boost

 

[2 cam sam]

I've owned both in supercharged form. I'm more of a purist, if its fuel injection keep it a fuelie , if its 2v keep it a 2v, if you want a 4v just buy one.

 

[oster910]

Im no engine builder but i would assume that if you want were to get a 4v i would try to get the engine of the cobra 03 or the 04 only because of the forged internals but if you already have a pretty nice 2v ,
I cannot comment on the airflow and what not since i do not know about much differences of the two but i would think if you had the 2v i would try to get it forged and maybe ported heads and blower cams. its not something you hear about very often but like i said im not an engine expert just saying what i know

 

[Stanger00]

You would have to change pistons too. Going from a 42cc chamber to 53cc is a big drop in compression.

 

[coposrv]

You would have to change pistons too. Going from a 42cc chamber to 53cc is a big drop in compression.

Exactly why if it has a built short block already just rock it.

 

[smkn99]

yes i have a d.s.s. racing 5.0 stroker shortblock and ported and polished heads, i think i am going to replace my pistons with 13cc pistons to bring me to 10.0:1 and do the tork tech kit with a ported eaton for now that i can always upgrade to a whipple.

 

[Dasaliac03]

Exactly why if it has a built short block already just rock it.

Agreed! Quite a few nasty 2v's rolling around my area

 

[kcobra]

MPH had plenty of 700-800 RWHP 2v cars. Stay 2 valve, get a 2.8 custom kit with upgraded intake and call it a day. Monster. My 2V saleen made 660RWHP and was fast as hell.

 

[Stanger00]

Seen lots of PI head 2 valves running 800-900 with KB 2.8's installed and with boost in the 20 range.

Turbo PIs also make a ton of power.

Seen a V2 Vortech pull over 600 with plastic PI manifold, untouched heads, cams and around 20psi.

People have been doing it for a long time now.

 

[Driver500]

stay with the compression you have now. You will make more power with more boost and less compression than less boost and more compression.

Since you are talking about going with a supercharger your off idle response will still be fine even with the lower compression.

You already have a potent motor setup. I made 780rwhp through a 4r70 on 24lbs using twin 57s with a built 4.6 and ported pi heads with a turbo cam.

 

[Svtmustang01]

Without a doubt use your built 2v. Theres no reason to buy a ~9,000 dollar swap. Then buy a 3500 dollar blower. Also termi swaps take time and money haha. Ive got 12,000 in mine without labor.