Hi all, I have a question about my setup. I have a 91 with 2000 miles on the new bottom end that is a forged 306. I currently have stock e7 heads, b303 cam, 1.6 rr, cobra upper and lower intake, CAI with Bassani headers and Bassani mufflers with no cats or smog. It is a manual with stock rear end. The car has really good torque and runs really well. What I would like to know is about what it's putting out HP and what would the gains be roughly with a set of GT 40 iron heads. Thanks in advanced
Cobra Gt 40s
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Here is what I've gathered from hang'n round here for awhile.
If you are on a budget and you already have the gt40's you will need to do a valve spring udate. They are a good update but keep in mind they are 'old school'. The stock heads are good for a stock motor, thats about all. Better heads are on the market now and they are bolt-n-go. Aluminum if you can, they are inexpensive and light weight, technology has advanced since the gt40 days.
What are your plans for the car? Street/strip or just looking to embarrass an import or two?
Think about a good gear in the back, say 355 or more depending on use.
If you are on a budget and you already have the gt40's you will need to do a valve spring udate. They are a good update but keep in mind they are 'old school'. The stock heads are good for a stock motor, thats about all. Better heads are on the market now and they are bolt-n-go. Aluminum if you can, they are inexpensive and light weight, technology has advanced since the gt40 days.
What are your plans for the car? Street/strip or just looking to embarrass an import or two?
Think about a good gear in the back, say 355 or more depending on use.
^^This
However with a better cam, larger TB, maybe some 24s (not necessary) and bumped timing = 250-260ish with an auto 260-270ish with a manual
They are guessing 215hp at the rear wheels (aka rwhp.....rear wheel horse power). This estimate is after power train losses.
For the money I would buy nothing less than trick flow 170cc heads... it'll be money very well spent
Gotcha I thought he/they was saying 215 flywheel. one of my builders have a 93 cobra thats really nice and sounds good but I roasted him so when I read that I was thinking does his cobra only make about 190 to the flywheel.. I'm not really sure what else has been done to mine. The guy that owned Dugan racing in Duluth GA was originally building the one I have for a turbo for track use and my girl bought it from him for a birthday gift for me ""good woman" after my 07 was totaled by a drunk driver. I do know the 91 feels much stronger then my 07 did but it was a auto also but hack on topic would a set of gt40x be a good direct bolt up?
The cobra probably makes more power. TFS heads will bolt up. What's your budget?
Mine, with totally stock long lock made 232 with 76mm MAM and long tubes off road H and 2.5 cat back... stock intakes/cam/TB/heads etc etc.
With a fresh 306 and the mods you listed I would expect wheel hp up over 230, because, most low mileage cars back in the day were over 230 at the tire. 240 was not uncommon.
In theory, a stock (as cast) set of GT40 irons "should" give you another 30. 260-270 seems to be the norm with that type of combo on a fresh bottom end... although having said that it's important to address the fuel pump and injectors to get there.
Pretty much any of the popular heads will "bolt on", but with any set, you are still looking at checking push rod length and PTV clearance because, anomalies.
Heads... it comes down to budget and desires.
You can make 350+hp to the wheels with Ford iron heads, but it will be a tonne (spelled in metric, because it's more) in $ over what a typical simple aluminum head setup will run you and drive-abilty may be on the poor side for your desires.
A typical aluminum head setup is going to make 280-300 given all the support items are there (fuel exhaust).
Getting over 300 at the wheels starts to become more involved, porting of heads and intakes, valve jobs, well matched cam/valve train.
So, bolt on some GT40 irons, possibly as much as 30hp more than the stock E7's.
You are sure the E7's are stock/unmodified right? Because if the guys at Dugan Racing worked those E7's over, it's possible a set of GT40 irons will net you very little, and, possibly even take you backwards.
With a fresh 306 and the mods you listed I would expect wheel hp up over 230, because, most low mileage cars back in the day were over 230 at the tire. 240 was not uncommon.
In theory, a stock (as cast) set of GT40 irons "should" give you another 30. 260-270 seems to be the norm with that type of combo on a fresh bottom end... although having said that it's important to address the fuel pump and injectors to get there.
Pretty much any of the popular heads will "bolt on", but with any set, you are still looking at checking push rod length and PTV clearance because, anomalies.
Heads... it comes down to budget and desires.
You can make 350+hp to the wheels with Ford iron heads, but it will be a tonne (spelled in metric, because it's more) in $ over what a typical simple aluminum head setup will run you and drive-abilty may be on the poor side for your desires.
A typical aluminum head setup is going to make 280-300 given all the support items are there (fuel exhaust).
Getting over 300 at the wheels starts to become more involved, porting of heads and intakes, valve jobs, well matched cam/valve train.
So, bolt on some GT40 irons, possibly as much as 30hp more than the stock E7's.
You are sure the E7's are stock/unmodified right? Because if the guys at Dugan Racing worked those E7's over, it's possible a set of GT40 irons will net you very little, and, possibly even take you backwards.
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