Ford Mustang Forums banner

1 - 12 of 12 Posts

·
Registered
Joined
·
1,022 Posts
Discussion Starter #1
347 - B50 block
Victor Jr. Heads, unported (milled to increase compression ratio to ~ 9.5:1)
Victor 5.0 intake
1 3/4 longtubes, 3" x-pipe, 2.5" catback
Pump gas
Tremec TK0 500
26" slicks
3.73's (3.90's or 4.10's not out of the question)
Crower 15513 camshaft (.512/.531 lift; 228*/234* duration; 112* lobe center)
~3300 lbs race weight

Of course with a professional dyno tune.


The cam is rated to about 6500 rpm, which is where I would run it to. I just want mid 11's and 120mph N/A. I'm selling my supercharger to fund the purchase of the heads/intake.

Any suggestions? I know I could use more compression, but right now I'm at 8.5:1 compression w/60cc heads, and I dont have the budget to replace the pistons. I figure going to a 50cc head would get me ~ 1 point of compression bump.
 

·
Registered
Joined
·
390 Posts
Your cam is a little small and alot of weight with the car!I would go solid roller and add a little more compression.But who knows,you should be around 115 plus!Good luck
 

·
Registered
Joined
·
1,022 Posts
Discussion Starter #5
more compression, more gear, more cam, and less weight and it will. LOL
Well then what to expect? I would hope it would at least put down ~ 375rwhp, is that more like 12.0's at 115mph?

It ran 106mph with small Edelbrock RPM heads and 8.5:1 compression, and a pig rich tune.


And I k now it SHOULD have been faster with the blower, but i only had it out ONCE with the blower and it lifted the head and popped the gasket after 3 passes. This also was with Ford racing shorty headers (tiny) and a VERY conservative tune. I'm sure with more tuning and practice it would have ran mid 11's and 125mph, but i'll never know.

How much compression is still pump gas friendly? 10:1? 11:1?

Dont forget that I can still always put a small shot on it if I ever really want to go fast.

I really just want to have a 11 sec car that starts every time, doesnt break ####, and is relatively streetable. My drivetrain is good for 500+hp, so i;m not worried about that.
 

·
Registered
Joined
·
705 Posts
Those pistons are going to hurt performance on a all motor setup. You can probably run around 10.5:1 compression on pump gas with no worries. You can run more than that with a custom cam that bleeds off some of that compression.
 

·
Registered
Joined
·
3,090 Posts
"I really just want to have a 11 sec car that starts every time, doesnt break ####, and is relatively streetable."

Your goal is fairly easy with a 347. It's just a matter of matching parts. The engine is only part of the equation. The suspension will have to be efficient so the car will hook and go straight. Finally, can the driver bang gears? Get all three close to optimum and you'll get the result you're looking for without too much trouble.
 

·
Registered
Joined
·
2,796 Posts
You have an 11 sec car now, and you want a whole sale change just to do it N/A????

why not just put a touch more agressive cam in it and let it eat?

Your combo, is actually not too bad. I think the headers are hurting you a little... I think you'd see a reasonable gain by going to an 1-7/8 primary..

If you've been 120 already, work on driving it, that mph is good for low 11's...
 

·
Registered
Joined
·
1,392 Posts
you should be able to hit the 11's but probably not 120 mph. you won't need that much mph for an 11 sec pass anyway.
 

·
Registered
Joined
·
1,022 Posts
Discussion Starter #10
I know it runs 11's now, but it lifted a head and it isnt worth repairing. I dont have the money to buy real nice heads + rebuild + full exhaust + real tune.

I liked having it blown, but I like driving it more. I have gotten to the point that I dont need or want a 10 sec car, and more importantly I dont want to worry about it breaking. I want to get in it and drive. Not worry about intake temps, is my meth system working, if my tune is off am I going to crack a piston, IS MY BLOCK STRONG ENOUGH?

Now I know tune is still very important for a N/A car, but catastrophic failures usually dont occur as often.

And I know I can drive it better, but I had very little seat time in it. I've only owned the car for 1.5 years, and only like 6 months of that time have been in warm weather when the car was put together. The 11.8 @ 120 was the first time I ever had the car to the track with the blower.
 

·
Registered
Joined
·
3,979 Posts
347 - B50 block
Victor Jr. Heads, unported (milled to increase compression ratio to ~ 9.5:1)
Victor 5.0 intake
1 3/4 longtubes, 3" x-pipe, 2.5" catback
Pump gas
Tremec TK0 500
26" slicks
3.73's (3.90's or 4.10's not out of the question)
Crower 15513 camshaft (.512/.531 lift; 228*/234* duration; 112* lobe center)
~3300 lbs race weight
I don't see it getting 120mph, even if it were 3000 lbs. The cam is a little on the small side and the compression is a little low. Get it to 11:1 with a bit bigger custom cam and at 3000 lbs it'll do 120-124 or so (as a 5 speed).

At 3300 lbs, you're going to need the compression and the cam to pick it up, full suspension setup perfectly, and the gear setup to match the cam and a good driver.

My old setup went 119.5 through an auto at 3050 lbs:
347ci 10:1
Ported Twisted Wedges 281/[email protected]
Lunati 51012 cam 544/560 232/242 112 lsa
Holley Systemax lower port matched to heads
75mm t/b, 30 lbs injectors, 77 pro m maf
1 3/4 longtubes to 3" exhaust
3.73 gears and 28" tires
4400 rpm stall speed

[email protected] with a 1.53 sixty foot was the best n/a pass. It would have gone faster with a custom cam.

As far as being streetable, a custom cam will get you that and good power. I just don't see it running more than 115 at 9.5:1 compression even with a custom cam.
 

·
Registered
Joined
·
2,796 Posts
I know it runs 11's now, but it lifted a head and it isnt worth repairing. I dont have the money to buy real nice heads + rebuild + full exhaust + real tune.

I liked having it blown, but I like driving it more. I have gotten to the point that I dont need or want a 10 sec car, and more importantly I dont want to worry about it breaking. I want to get in it and drive. Not worry about intake temps, is my meth system working, if my tune is off am I going to crack a piston, IS MY BLOCK STRONG ENOUGH?

Now I know tune is still very important for a N/A car, but catastrophic failures usually dont occur as often.

And I know I can drive it better, but I had very little seat time in it. I've only owned the car for 1.5 years, and only like 6 months of that time have been in warm weather when the car was put together. The 11.8 @ 120 was the first time I ever had the car to the track with the blower.

First time out and it went that.... Fix what you have!!!!! With seat time, you would be down in the lower 11's. That's damn fast for a street car/ dd.
Stud the heads (if they aren't already), use MLS or cometic head gaskets, and slow the blower down. Put a 3.33 pulley on it...
Leave the exhaust alone... This may sound a bit funny, but that s/c combo will get better gas mileage than the n/a any day of the week!!! :salute:

When you say "lifted the head" did it just blow a hg? Or did it fire slot the head? (Burn a hole between chambers) 11#'s isn't that much boost, if it hurt the head I'd be looking else where for an issue (fuel system, timing, tune).... I used to run 15-16#'s with only a 1011-1 head gasket. And a damn FMU!!(1996 timeframe) The tech in head gaskets, and chip tuning is killer now, you should have NO problems keeping it together....

It's your car, do what you want, it just seems like you already have all the pieces to have a really fun street car. It's just a matter of getting it sorted out.:salute:
 
1 - 12 of 12 Posts
Top