Gn1 vs champions irons

[Cleaner13]

ok can anyone tell me the the flow #s of these two heads

the GN1s champion aluminums and the champion irons

thanks

Carl

 

[NJTurbo]

Carl,

To get numbers to the tee. Call Champion speak to Tom. I have seen the numbers all over the place also keep in mind GN1 and GN1R are different. I have seen GN1 and then guys take to machine shop to go even furthur with them. Based on your budget Alot of guys going 10's with irons.

 

[frankg]

From what i've read this is what i remember them flowing:
GN1's- 220-225 cfm intake
CNC Irons-200-205 cfm intake Frank

 

[S2V6RACER]

My Gn-1R's were flowed at 241.4 at .550 intake and 182.1 on the exhaust at .550. Test bore Dia 4" at 28" W.C.


These heads were ported by Tom and the guy that flowed the heads laughed at me when I told him what it costed to have them ported.

 

[FRCEFED6]

gn1s

my gn-1's flow 249cfm @ .550 and 219cfm @ .600. they were ported by a guy on the west coast for $800. motor isnt together yet but it should be scary fast. jeremy

 

[Nick Micale]

Originally posted by frankg
From what i've read this is what i remember them flowing:
GN1's- 220-225 cfm intake
CNC Irons-200-205 cfm intake Frank

Our numbers are very close to Frank's. We have flowed a few sets on GN-1's and lots of maxed iron heads. With the same flow bench and operator, here is what we got:

All on intake at 0.500" lift:

stock max port, 1.77" valve iron.........210 cfm

GN-1 out of box..................................230 cfm

GN-1 Champion ported.......................257 cfm

GN-1 ported by us..............................260 cfm

 

[JeffG]

Nick,
This may be a lame question but here goes anyway...................... theoretically speaking (on two identical turbo motors) how much horsepower difference is there in 50 cfm?

Thx,

 

[Nick Micale]

Originally posted by JeffG
Nick,
This may be a lame question but here goes anyway...................... theoretically speaking (on two identical turbo motors) how much horsepower difference is there in 50 cfm?

Thx,

Am sure others can give you a more accurate answer as I can only say what I have experienced.

On 2 local GN's with the same engine build/cam except for GN-1's vs. big valve, max ported iron heads, do have info on their performance. Both cars have similar 60' times and both running V-4 intercoolers and TE-45A turbos.

The iron head car runs easy low 11's and has seen high 10's. With alum heads, other GN ran mid-10 sec., and now will be low 10's w/front mount and a TE-70. The iron head GN needs 27-28 psi boost for 10's which is same boost level the alum GN normally runs.

How about a guess of over 1 HP per cfm!

 

[JeffG]

Wow, that's a bit more then would have guessed. Thanks!

 

[S2V6RACER]

What is significant on this thread, is if everybody sent thier heads to Nick and had them flowed, then we would be comparing apples to apples. I got a little lesson the other day on flow benches and how easy it is for people to fudge their numbers and how flow benches vary.

Nick is correct on the iron heads. My stock block falls on it's face below 26 psi.

Ted