[Boostang]

fully forged 11:1 cr 2v.. or a 9.1:1 cr 4v (b heads)

 

[03_StangGuy]

9.1:1 wont show gain with out boost

 

[RyanGT]

The 4v will see better gains overall. Maybe not with direct swap (2.0 cr difference) but with a few bolt ons it will easily pass it imo.

 

[Boostang]

what kind of bolt on should i start off with?

 

[neverfastenough1]

what kind of bolt on should i start off with?

A Procharger or Kenne Bell.

 

[ajm]

Whats done to the car to begin with?

 

[BakerFX4]

definitely a KB. lol

 

[Boostang]

haha thats far form a bolt on in my book!! lol
but it has a tremec tko 500.. 4.10s.. 100 shot.. and a cai that goes to a 2v.. wont work if i go to a 4v

 

[Pittbull]

stupid question..

but what is a '2v' and a '4v'???

 

[Boostang]

2 valve='s gt.... 4v='s cobra

 

[dcook_14]

stupid question..

but what is a '2v' and a '4v'???

2 valve and 4 valve per cylinder. GTs came with 2 valve motors, cobras and i believe machs came with 4 valve

 

[Pittbull]

OH VALVES!
gotchaa
thanks

 

[neverfastenough1]

cobras and i believe machs came with 4 valve

And a host of other cars, but we will just stick to Mustangs for the record.

 

[neverfastenough1]

I'm going to go out on a limb here and say that if your future plans are not in the direction of a supercharger, you will get more gains from the 11.1 cr. The 9.1 cr is lower than stock Gt's. Granted you will get more performance than you would from an unsupercarged termi motor, but still about the same as a stock GT with ported heads (maybe a little less). '01 Cobras are around 11.5 or something like that, and they get 320 to the crank, about 285 to the wheels I would guess. I think unboosted you will get more from 11.1 cr with some cams than the 9.1 cr. Just my opinion, and I am only an expert on Mondays, which ain't today.

 

[Boostang]

so if this was ur decision u would go with the 11:1 cr 2v over the 9:1 cr 4v?
am i correct?

 

[03_StangGuy]

If you dont wanna run boost go high compression, if you do you want low compression. Personally Id go low compression and some form of boost.

 

[Boostang]

well see i bought these pistons to put my 2v heads on but i came across a cheap 4v motor so i jumped on it.. but i didnt think the 4v heads combusion chamber was that big to drop it 2 points

 

[neverfastenough1]

so if this was ur decision u would go with the 11:1 cr 2v over the 9:1 cr 4v?
am i correct?

Yes, I have been teetering on the lower cost of a '01 Cobra short block with some TFS heads vs forging my block with some TFS heads and a blower. If I were to decide to not go boost, I would go with the higher compression. The fact that boost will give you alot more potential in a 4v with low compression vs the limited power you will get from a higher compression set up is what you have to decide. Take a look at the thread on the TFS heads. He has a '01 Cobra block (11 something:1 compression ratio). He is so far limited to under 400 hp. Not knocking it, but a supercharger on a stock block will gain more or at least the same with all of that hassle. Some people just want to be N/A, and that is respectable. I for one appreciate the hard work he is putting into it, and hope he gets what he is aiming for. To answer your question, yes, between a non boosted 9.1 and a 11.1, I would take the 11.1 w/ported heads (2v or 4v) and cams.

 

[Boostang]

how safe would it be if i ran my nitous kit on a 9:1 cr 4v?

 

[neverfastenough1]

That will be a question for one of those nitrous guru's like Sweet. I would think as long as you don't go beyond the limits of the inerds that it would be the ticket.