I was talking to a friend about a set of GT40P heads he has and he was telling me that the stock springs are good to up to 700hp, how true is that and shouldn't there be a RPM rating as well?
Thanks
Thanks
Time to get new friends. Valve springs aren't rated for HP or RPM. Do a search here or look at the anything/everything gt40 thread on the other forum and you will find what you need.I was talking to a friend about a set of GT40P heads he has and he was telling me that the stock springs are good to up to 700hp, how true is that and shouldn't there be a RPM rating as well?
Thanks
get the TFS spring upgrade and make sure your friend never works on your car.
I thought so, I knew it didn't sound right. lol although this is the same friend who thought an alternator was a supercharger in high school.
Sounds like a girl i knew back in the day that thought the button on the shifter of her Naturally aspirated eclipse's automatic shifter was for turbo boost. Turns out it was to turn over drive off, lol.
Anyone here spent the money on porting some gt40p's? What were the results?
Yes, I understand that. I'm asking more for someone who would be sanctioned in a league that only allows "stock" cast heads.Gt40p heads $250
Valve springs $100
Valve job $200
porting $200-$400
Mathematically it's just not sensible when used aluminum heads can be found for around $750
Yes, I understand that. I'm asking more for someone who would be sanctioned in a league that only allows "stock" cast heads.
Ah, yes. May use gt40p heads in OEM form. Thanks, buddy.I thought most of the stock rules didn't allow for porting, but allow for valve work. And those valves they use are very expensive.
The guys that know what they are doing can make 350rwhp. It's far from cheap and streetable, but it can be done.a