champion GN1 and GN1r heads CFM max HP?

[Crispy Chicken]

Above all, what are the power limits / cfm numbers. on champion GN1 and ported GN1-r heads.. Aside from times. Where are these maxed out at in HP. Where stage 2 heads would take over.. Thanks guys..

 

[fxdxlr8]

I don't know about GN's. My TA heads maxed out at 255 cfm @ .550. The Stage 2 heads I have are 298@ .500 but continue with 320@.600 and 325@.700. Hope the info helps.
Both numbers are intake.

 

[bison]

Imo flow numbers mean about nothing. TA's and Champions have made well over 1000hp. All to my knowledge ran solid roller cams with aggressive ramps. Spring selection and camshaft will dictate the potential of the engine to rev and make use of higher flowing heads. They will do nothing or hurt power if the engine isnt using the extra port volume even though they may flow more.

 

[Grumpy]

Imo flow numbers mean about nothing. TA's and Champions have made well over 1000hp. All to my knowledge ran solid roller cams with aggressive ramps. Spring selection and camshaft will dictate the potential of the engine to rev and make use of higher flowing heads. They will do nothing or hurt power if the engine isnt using the extra port volume even though they may flow more.

X2 !! lots of guys are hung up on flow #s .

 

[cruzn57]

flow numbers

are just like anything else, comp ratio, clearance, cam size, valve size,etc.
you need to know the numbers!
if your heads haven't been flowed, how do you know if the ports flow equally?
also knowing that the ex is a particular % of intake is also quite valuable for cam/ intake selection.
flow benches differ, so do not expect same head to flow same numbers on other benches, your looking for good flow at low lift also.
Yes some people do get hung up on "how much did they flow"?
but flow benches are another good tool to be used in engine building.

 

[Crispy Chicken]

Thanks a lot guys for the info..

Yeah it seems like the profesnioals, people that race at the highest level's huge money race teams in different type's of racing . care about flow a lot, in both na and forced induction engines. I suppose to the average buick hobbest head flow or really anything else doesnt matter to too much, as long as it runs pretty good..


I am trying to find out facts. Above everything else in the set up. Where they are in flow hp. How far have they been pushed. I am trying to decide if I want to use stage 2 heads or not in my build. I have a set of gn1 and stage 2 heads right now. I need the heads to be able to flow at least 1100 1200 hp.. With out being a restriction.

 

[turbofabricator]

If your target is 1200+, then jump directly the the StageII, (or LSX) and don't look back.

 

[Crispy Chicken]

around 1000 wheel or so....

 

[Crispy Chicken]

I learned that the gn1 heads I have crack at that power level.. sooo stage 2 heads it will be. After its running the extra money and time waiting to get everthing going will be worth it. Thanks for the help guys!

 

[turbobuick]

Imo flow numbers mean about nothing. TA's and Champions have made well over 1000hp. All to my knowledge ran solid roller cams with aggressive ramps. Spring selection and camshaft will dictate the potential of the engine to rev and make use of higher flowing heads. They will do nothing or hurt power if the engine isnt using the extra port volume even though they may flow more.

What Bison said is what you need to understand but unfortunately it is not easy to understand In a turbo motor there is a lot more to it than head flow and there is VERY little information out there on it especially when it comes to cam profiles. In a turbo motor understanding compressor maps how it relates to engine efficiency and rpm make a much bigger difference in performance than head flow. Good case and point a max port TA or GN1 head can reach 280-300 cfm, an average S2 can get 320-340 on intake. Take your avg TSM combo with a 70mm turbo and I would almost bet the car would slow down with S2 heads, regardless if it didn't slow down it definitely wouldn't be any faster.

In TSO where we can run a much larger 88mm turbo this has been a debate we've had for many many years. With a larger turbo the better S2 heads should be more efficient at higher rpm thus allowing the motor to extract more power from the turbo, or so it would seem. The times in my sig were run with GN1 heads in TSO trim.

 

[Jerryl]

What Bison said is what you need to understand but unfortunately it is not easy to understand In a turbo motor there is a lot more to it than head flow and there is VERY little information out there on it especially when it comes to cam profiles. In a turbo motor understanding compressor maps how it relates to engine efficiency and rpm make a much bigger difference in performance than head flow. Good case and point a max port TA or GN1 head can reach 280-300 cfm, an average S2 can get 320-340 on intake. Take your avg TSM combo with a 70mm turbo and I would almost bet the car would slow down with S2 heads, regardless if it didn't slow down it definitely wouldn't be any faster.

In TSO where we can run a much larger 88mm turbo this has been a debate we've had for many many years. With a larger turbo the better S2 heads should be more efficient at higher rpm thus allowing the motor to extract more power from the turbo, or so it would seem. The times in my sig were run with GN1 heads in TSO trim.

VERY well put with the results to back it up.

 

[Crispy Chicken]

a max port TA or GN1 head can reach 280-300 cfm, an average S2 can get 320-340 on intake.

Thank you for that info.. I don't think I was clear enough in my first post. I am focusing on head casting design strenght limits etc. Like I said above all. I don't mind people giving me advice on the importance of fine tuned combos set up properly for their intended use goals. Not looking for combo and tunning info. Trust me I know how cramming air into vacuum cleaners works. Right now I'm at. Heads heads. I am going to set up and tune my combo after I choose the head I need. Strenght is a big factor too. I want to know what I have and why I am using it or not. I know nothing about my GN1's. Am I wrong in asking learning about the heads I have? I could take them and flow them my self but I was trying not to. Because I know enough people are running GN1's here. Your times are very nice. Which gn1 castings do you have. Mine where bought new in late 2002. I was told they have problems cracking when making a lot of power. Then someone told me they made a better casting which only a few people have. It seems like from what I found TA makes a better stronger casting over all. Is this true?

 

[BlownV6]

Thank you for that info.. I don't think I was clear enough in my first post. I am focusing on head casting design strenght limits etc. Like I said above all. I don't mind people giving me advice on the importance of fine tuned combos set up properly for their intended use goals. Not looking for combo and tunning info. Trust me I know how cramming air into vacuum cleaners works. Right now I'm at. Heads heads. I am going to set up and tune my combo after I choose the head I need. Strenght is a big factor too. I want to know what I have and why I am using it or not. I know nothing about my GN1's. Am I wrong in asking learning about the heads I have? I could take them and flow them my self but I was trying not to. Because I know enough people are running GN1's here. Your times are very nice. Which gn1 castings do you have. Mine where bought new in late 2002. I was told they have problems cracking when making a lot of power. Then someone told me they made a better casting which only a few people have. It seems like from what I found TA makes a better stronger casting over all. Is this true?

Go to the Turbo Lounge - Chit Talker are you going to BG. Also a post that Chit Talker did a couple months ago (search Chit Talker post in the lounge) that was closed by Admin. That should help you with your decision!! Mike

 

[bison]

In TSO where we can run a much larger 88mm turbo this has been a debate we've had for many many years. With a larger turbo the better S2 heads should be more efficient at higher rpm thus allowing the motor to extract more power from the turbo, or so it would seem. The times in my sig were run with GN1 heads in TSO trim.

Imo the ex side of the turbo is still a huge restriction in TSO especially at your level.