i recently got a pair of gt40, not p heads and was planning on installing tfs springs, tfs stage 1 cam (or e303 cam) and 1.7 roller rockers. im wondering if anyone has this combo and any imput on how it runs and if they like it. 1/4 mile runs and horsepower numbers would be great. and which cam to run. and i havent heard a tfs stage 1 cam, i dont no if its lopey or not. my setup is shorty headers, 355 gears, 5speed, tfs upper intake (came on car when i bought it, no lower), cold air intake, upgraded mas air flow. i also have 24lb injectors not yet installed. stock bottom end. any advise or info would be great.
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Double check your clearance with gt40's/TFS or E303 and 1.7's... Find someone with this combo, or check with the store you buy the 1.7's from. There is also a Ford SVT hotline but I don't know if it's operational anymore.
I bought 1.7's and found out that with my B303 and gt40x heads I had to use 1.6's
I bought 1.7's and found out that with my B303 and gt40x heads I had to use 1.6's
I bought my car with a GT40 head setup, TFS Stage 1 and 1.7rr. I pulled the heads to port and mill them. I was going to have to lose the 1.7 and go to 1.6s in order to mill them. Ended up having to rebuild the motor so I got aftermarket pistons and didn't have to worry about clearance. The valves barely even made an impression in the clay when I checked it on my aftermarket pistons (Probe SRS).
The previous owner had the car dynoed and tuned using a Diablo Chip. I have the dyno sheet: 268 RWHP & 304 RWTQ. This was using stock short block, 9.0:1 compression, Ported Cobra Intake, GT40 Heads, 24lb injectors with C&L meter, shorties and full exhaust, deleted smog and still had clutch fan.
Do a Google search on gt40 dyno numbers. There is an old thread in one of the forums where several guys are making 300+ RWHP. This takes ported heads, ported intake or aftermarket (something more than Cobra or GT40 unless well ported) and a good cam (maybe even custom).
When I did my rebuild I used a stroker kit (331) because of the financial end of it...it was only about $500 more to do the stroker. I ported the heads myself, my machinest did a valve job and milled the bowls wider, then blended them into my ported runners (use the DIYPORTING website...good info). My heads were milled up just enough to clean them (.015) and I switched to a hand me down Edelbrock Performer intake. I ended up with 10.15:1 compression.
I reused my TFS 1 cam with 1.7rr, just because I couldn't afford another cam at this point. But, I am kicking myself for not buying a bigger cam now. I really like the AFM N21 and N41 cam. The TFS sounds good, but it isn't that 60's muscle car sound either. I haven't had my car dynoed or tuned yet, but I am hoping that with the better intake, ported heads, more compression and more cubes, hopefully I have picked up about 30-40 rwhp. I hope to be in the 310 rwhp range by the time I have it tuned. I may be way off, we will see.
The heads are a good budget upgrade if you don't spend too much. Be carefull, they can become a money pit. I put $400 in mine with the mill clean up, valve job, bowl work and new springs. But I got them for "free" on my car, so I didn't mind. But if you have to spend $300 bucks to even buy them...well, not really a budget anymore.
Sorry for the long post, I could talk about it all day!
It was a fun project. Take your time and do the port work if you feel comfortable with it. Definetly mill them if you can afford it. Compression helps. If you have a choice, use the 1.6rr so you can mill them a bit, you won't gain anything from the extra lift on these heads. If interested, the N21 cam and N41 cam are the same thing, one is just designed to make the same lift with 1.7s versus the 1.6s.
Good luck with it! Let us know how it goes.
The previous owner had the car dynoed and tuned using a Diablo Chip. I have the dyno sheet: 268 RWHP & 304 RWTQ. This was using stock short block, 9.0:1 compression, Ported Cobra Intake, GT40 Heads, 24lb injectors with C&L meter, shorties and full exhaust, deleted smog and still had clutch fan.
Do a Google search on gt40 dyno numbers. There is an old thread in one of the forums where several guys are making 300+ RWHP. This takes ported heads, ported intake or aftermarket (something more than Cobra or GT40 unless well ported) and a good cam (maybe even custom).
When I did my rebuild I used a stroker kit (331) because of the financial end of it...it was only about $500 more to do the stroker. I ported the heads myself, my machinest did a valve job and milled the bowls wider, then blended them into my ported runners (use the DIYPORTING website...good info). My heads were milled up just enough to clean them (.015) and I switched to a hand me down Edelbrock Performer intake. I ended up with 10.15:1 compression.
I reused my TFS 1 cam with 1.7rr, just because I couldn't afford another cam at this point. But, I am kicking myself for not buying a bigger cam now. I really like the AFM N21 and N41 cam. The TFS sounds good, but it isn't that 60's muscle car sound either. I haven't had my car dynoed or tuned yet, but I am hoping that with the better intake, ported heads, more compression and more cubes, hopefully I have picked up about 30-40 rwhp. I hope to be in the 310 rwhp range by the time I have it tuned. I may be way off, we will see.
The heads are a good budget upgrade if you don't spend too much. Be carefull, they can become a money pit. I put $400 in mine with the mill clean up, valve job, bowl work and new springs. But I got them for "free" on my car, so I didn't mind. But if you have to spend $300 bucks to even buy them...well, not really a budget anymore.
Sorry for the long post, I could talk about it all day!
It was a fun project. Take your time and do the port work if you feel comfortable with it. Definetly mill them if you can afford it. Compression helps. If you have a choice, use the 1.6rr so you can mill them a bit, you won't gain anything from the extra lift on these heads. If interested, the N21 cam and N41 cam are the same thing, one is just designed to make the same lift with 1.7s versus the 1.6s.Good luck with it! Let us know how it goes.
Oh yeah, about the track times. I only made two passes on old combo. I was smoking the clutch leaving the line (full weight car, about 3450 with me in it). My 60ft was a 2.121 (yea, I know) and I went 8.81 @ 82.41 mph. The mph was very high for the time. I probably should have gone 8.4X or so. This would have been low 13's in the 1/4. Not that impressive, but maybe average for the average guy. I am definetley hoping for some low eights in 1/8 mile and high 12's in quarter next time I'm out.
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