Ford Mustang Forums banner

1 - 20 of 25 Posts

·
Registered
Joined
·
52 Posts
Discussion Starter #1
Hi there..My name is Bryan and here is my setup:
89 Mustang GT
306 11:1 comp
stage III TFS cam (236/248 @.050.. .575/.595) 110 lobe center
1.6 Scorpions
Chromemoly pushrods
Eagle rods
TRW Forged flat top pistons
GT40 lower (ported to 1262)
RAP (box) intake upper
75MM MAF cal/ 24LB inj
80 MM BBK throttle body
stock Duraspark (have Mallory IV to put in)
Victor Jr heads 2.05/1.60 (ported/polished and milled .055)
1 3/4 BBK long tubes
dual 3 inch Borla XR-1
255 lph tank pump
no EGR plate
no smog
I have built this thing to be N/A around the 450HP range. I built it around a couple of articles and mainly around the 306 that dynoed [email protected] rpm. Surprisingly enough it idles @ around 1100 rpm very rough and choppy. I obviously need a chip of some type. I have the 24 lb injectors in there right now and I have 38 to put in there with a 80 MM MAF to match. I have the fuel pressure up to 50 to get the plugs colored. I also have the timing set at 18 with the dist unplugged and it does not ping...even in 5th gear @ 2000 and climbing a hill. The motor is 2 weeks old and I have not done a comp test..but it was computed out to be 11:1. How much timing can a SBF take? What chip do I go with? Diablo..Autochip..or just take it to a yno and get them to tune it? and if so ..WHERE???...Help me out nobody in Waco runs a head/cam combo this big and really don't know.... Thanks.
 

·
Registered
Joined
·
4,254 Posts
First let me say, NICE 306, and even more impressive are those numbers :eek: Was that 489 @ the wheels? Do you have an R block?

Anyhow I would suggest a dyno tune, I myself had a mail order chip, but I sent it back. The dyno tune is the way to go. As for location, I am not sure, maybe someone here lives in your area and can help out.

What tranny are you running?

Ian
 

·
Registered
Joined
·
1,137 Posts
Nice setup. We're going down very similar paths with 306s. Did you have your rotating assembly balanced? That's a critical step for a motor that's going to see almost 7000 rpm.

I'd suggest an EEC Tuner or a TwEECer. Then take it to a dyno with wide band O2s and tune it.

If you have a local shop that can tune it and burn you a chip that would be fine also.
 

·
Registered
Joined
·
479 Posts
Can you guys read?

"I built it around a couple of articles and mainly around the 306 that dynoed [email protected] rpm."

These numbers are not from his motor...

I think those numbers are very optomistic for that setup. I also see you having a hard timing getting that cam to rev much above 6500rpm regaurdless of what springs you run with it. You will need those 38lb injectors, and you will need a chip to spin the motor that high if it is still making power up there, (anything past 6250 will be an issue). I would recomend getting a custom chip that is burned for your combo on the dyno. Also I hope you are not running a stock based crank and block, because they will not last long at those rpms. I also hope you got the motor interanlly balanced, if not I would recomend putting a larger long runner intake on it and keeping the revs below 6500, you may be happier with the power output with a long runner if you drive the car on the street as well. I'm not talking about a Cobra intake either, maybe a Holley (slightly ported) or Victor 5.0 or a TFS R.

The detonation will not occur at 2000 rpm, but at the peak torque, which will be a lot higher then 2000rpm (more like 4500-5500rpm).
Please let us know what kind of numbers you get when you put it on the dyno. I am running the same cam in my 347 and it is pretty lumpy in my car even with the extra 45cubes.
Good luck, Tom.. :)
 

·
Registered
Joined
·
1,137 Posts
Turbo92coupe said:
Can you guys read?

"I built it around a couple of articles and mainly around the 306 that dynoed [email protected] rpm."

These numbers are not from his motor...

Duh!! Of course they aren't from his motor. Maybe you can't read since I never said anything about those numbers and his motor. :rolleyes:

With that combination he'll be spinning well past 6500 rpm and probably have a shift point around 6700-6800. Stock block and crank will be fine at those kind of rpm levels in a street/strip car. A road race car would be a different story of course. ;)
 

·
Registered
Joined
·
52 Posts
Discussion Starter #6
I AGREE!!

I was hoping for 450 hp...around 6800RPM. I have steel rods and the bottom is balanced. The stock block should be durable up to 500 but not much past that. And it IS my everyday car..so I don't see that RPM all the time. I was asking about the timing..how much can or SHOULD they take?! I'll have to put in the 38 LBer's and watch the fuel pressure to see if I have enough..I assume somewhere around 42 LBS?!......thanks........Bryan
 

·
Registered
Joined
·
184 Posts
I had good luck with 18 degrees base and 39 total - dyno adjusted. This was on a mild GT-40 application putting 275 to the rear wheels.
 

·
Registered
Joined
·
479 Posts
86Cobra that post was actually intended for 88COBRA, sorry for the confusion, I guess I should not have used the plural form of guys. :)

I disagree about the rpm level the motor will be able to operate at. His combo says 6800rpm, but his cam selection says 6300-6500 and then massive valve float. I can tell you first hand that the profiles on that cam will not support valvetrian speeds that high using stock lifters. The spring rates required to get to that rpm level would cause the hydr. lifters to keep from pumping up. I am curious to see what kind of power this motor does put out though, as it is a serious combo. I would also like to see how an intake change would effect its power output. I know my old 351W made peak power @ 6900 rpm and really liked the breadbox for horsepower, but gave up a lot of torque in exchange. I wish the TFS and Victor 5.8 had come out when I had that combo as I might have been able to get the best of both worlds. I have also thought about trying the Victor 5.0 on my 347, but have not had the time or money to play around, so for now the ported Saleen setup will have to stay.
Tom.. :)
 

·
Registered
Joined
·
52 Posts
Discussion Starter #10
WOW I am surprised !!

First off..that number was at the flywheel. Next my springs are 130 closed 400 open. And I have a friend who runs a 331 with stock lifters..his class "makes" him run them..and he comes across the line at 7200 RPM. I was surprised to think that my cam was NOT big enough to go that high. I am thinking about going to a Victor Jr with the 1 inch spacer for lower rpm. Right now the car goes wild at 3800-4000...but I have the stock comp and have to shift at 6000. I thought this was about the biggest hyd roller they make. I believe Comp makes a 240/248 duration..and I thought it would be enough to go to 7000...hm..interesting..........Keep the thoughts coming......INPUT...INPUT.....lol
 

·
Registered
Joined
·
1,137 Posts
It's not just the size of the cam that will get you to higher rpm ranges. The lobe profiles have to be right to get a hydro roller to rev that high. Turbo92coupe is saying that the TFS III cam doesn't have the right lobe profiles to do the job. He's probably right.

You're best bet is to get a good custom cam designed for that rpm range and your heads and intake.
 

·
Registered
Joined
·
52 Posts
Discussion Starter #12
86cobra

your setup is somewhat close to mine..have you ever dynoed yours? also how do you like the EEC-tuner? I am looking to getting something like that. Also I thought that a 110 lobe center would allow you to rev with the high lift numbers. Just a thought...they (TFS) said that the RPM range was around 6800.
 

·
Registered
Joined
·
1,137 Posts
I like my EEC Tuner but if I was buying again I'd seriously consider the TwEECer as it looks like it has more features.

I haven't dynoed it or run it at the track yet since I'm still chasing a pesky tuning problem. I should have it sorted out soon. Then I'm switching to a Holley intake as soon as I have numbrs with the Track Heat. I'm guessing around 350 rwhp with the Track Heat and 370 with the Holley.

BTW, I tried to reply to your PMs but your box is full.
 

·
Registered
Joined
·
52 Posts
Discussion Starter #14
Tweecer..that is the new system right? Where do you get it..who makes it? What is the tuning prob? What about the Crane intercepter..is that any good??? What rpm is your limiter set at? Why are you going to Holley..the Systemax? It is good to see someone else going N/A with a 306.......lol
 

·
Registered
Joined
·
1,137 Posts
www.eec-tuner.com

www.tweecer.com

I don't know anything about the Crane Interceptor except that it's been around forever.

I'm running really rich and it falls on its face at about 6300 rpm. I've been chasing it for a few weeks and I've tried a million different things and haven't solved it yet. I've checked and/or replaced all of the following - fuel pump, fuel filter, MSD, coil, distributor, EEC, mass air meter, and valve springs.

I currently have a 6800 rpm pill in my MSD but I'll probably run a 7000 when I finally get it running right.

The Holley Systemax is a nice intake. I've also considered the TFS R and the Vic 5.0 but I think the Holley is the best match for what I'm doing. TEA tested the Holley against the Track Heat (ported) and the Holley killed it on a N/A 306.
 

·
Registered
Joined
·
52 Posts
Discussion Starter #17
Hey Bigdaddy

Is the bread box (intake) really that big as far as the RPM's?? I know my buddy runs it on his 331 S/C and he runs 6500 RPM, but runs it because it is great for blowers...apparently not for the RPM band huh.......My car is a real pig under 3800-4000..then it breaks the tires loose.......:evil:
 

·
Registered
Joined
·
479 Posts
The bread box was really only good for high revs before they came out with the newer shorter and larger runner intakes, like the ones I listed above. The bread box setups can move a lot of air, but lack the runner length to make torque. They also require a really ported lower to reach the kind of RPM you are talking about.
The older style long runner intakes just couldn't sustain the airflow required to make power that high NA. Your buddy would pick up both horsepower and torque if he made the switch to a larger long runner intake. The blower will effectivly add about 1000rpm to the power band of a NA combo that is the same. So even a ported Cobra setup would still make power to 6500 and make lots more torque with little to no loss in horspower. Although I would recomend something a little larger. I don't think that your friends or your intake choice is optimal for your combos.
Tom.. :)
 
1 - 20 of 25 Posts
Top