Help w/friend's car

I put this here because it's a SBF.  We are trying to get this thing to MPH but it refuses.  Just put a brand new converter from Lenny in and it made almost zero change yesterday at the Spring Break Shoutout True Street event.

Here's the combo:

65 Mustang Coupe
408 Cubic Inches
192 cc canfield heads Unported
Vic jr Unported
Cam HydRoller - 242/250@ .050 585I 577E on a 110 Sep
QF Q850
10.15:1
1 3/4" hooker super comps
34 deg timing
Spectre Ram Air (slows down without it)
2 1/2 exhaust w/Hpipe, DynoMax muffs
C4 w/Gear Vendors
3.89 gear
all Calvert suspension
Hoosier QT Pro 27x10.5x15's
3255 lbs with driver
Converter - Had a 3800 and the new one is a 4900 - made no difference
shift 6500 crossing at 6400

Some of the times, which are basically exactly same with both converters:

1.54  7.08@95   11.237@117.6

1.52  7.09@95   11.24@116.47

I'm thinking it should run at least a 10.80 and around 122 in the MPH department.  Appreciate any input.







Here's a launch:

Exhaust 3" carb jetting fuel psi float level is what I would suggest . Maybe. A 4:10 gear would help the 60 ft and et IMO .

I would go after the cylinder heads, and a little bigger cam, say 10 more degree's or so at .050". AFR 220's is what a friend had on his 408, and they did very well. Your new convertor should respond well to the above upgrades. At 6,400 through the lights, I doubt a gear change will help. You might also try lowering the shift points 100-200 rpm and see what the times look like. The 60 foot times look good for the combo to me. With 10/1 compression, you might play with the timing a little (more advance) and see what it does, as well as the jets, you might pickup some MPH.

Looks like a converter change would have helped it or hurt it. I'd check the fuel system first and then make sure the car rolls easily.. My old car had disc brakes that were not releasing completely.

If you look at the times he posted, it looks like he picked up a tiny bit on his 60 ft. and lost 1 MPH, but that is more than likey just different track conditions and weather. I wonder if he might be loosing a little traction with the looser convertor, and can't tell by the feel of the car? If this is the case, and the extra convertor slipage of the new convertor would make more sense, as to no increase/decrese in MPH. A fuel pressure guage he could see on the cowl would be nice also. He did not mention what fuel he is running, either, thats why I mentioned timing. Or the Cheaters screwed, and the Rims/Tires marked? The Chevy Camaro Cowl hood is more than likely whats keeping him out of the 10's.  

supervel45 wrote:I would go after the cylinder heads, and a little bigger cam, say 10 more degree's or so at .050". AFR 220's is what a friend had on his 408, and they did very well. Your new convertor should respond well to the above upgrades. At 6,400 through the lights, I doubt a gear change will help. You might also try lowering the shift points 100-200 rpm and see what the times look like. The 60 foot times look good for the combo to me. With 10/1 compression, you might play with the timing a little (more advance) and see what it does, as well as the jets, you might pickup some MPH.

I don't think the cylinder heads are the problem. Going off of personal experience my first 393W . It was 10.5:1 with 185 AFR's vic jr intake 750 dominator 1''5/8 headers Reed cam with the following specs lift intake .587 exhaust .610 duration @ .050 intake 261 exhaust 268 lsa 108 thru 2 chamber flowmasters and 3'' exhaust 28'' tall tire c4 4000 stall 4:10 gear 3400 lbs with driver . On foot brake went 7.29 1.60 60 ft @95 MPH 1/8 mile. I change headers to 1"3/4 long tube and 1 chamber flowmaster mufflers and went 7.20 @ 97mph with the same 1.60 60 ft times 1/8 mile .

This was in a car with very poor traction and weight transfer and also needed more converter.

Exhaust, carb jetting, spark plug gap, and timing . I would also check dist advance, then would look at changing camshafts before changing heads. good luck.

http://www.carbdford.com/tech/flowdata.htm There are alot of things he could do and check. He could also do some port/flow work on his stock Canfields, and see what happens, also, with the cam he has now. It was just a suggestion, and I am sure there will be many more to come. I think he will get into the 10's with not much of a problem, or too much more expense.

Thanks, guys. I think we're looking at the exhaust at the moment to see if that's a cork.

We know the heads are small, but it still made the power it made so should be a bit faster.

Checking the exhaust and gonna flow the fuel system and go from there.

Keep the ideas coming if you think of anything else.

Oh, and another thing, I want to say this wasn't meant to disparage Len or UCC. I actually recommended my friend to go to him for a converter because I thought that was the issue. I'd still do the same and my friend has told me that Len's customer service has been great!  

dfree383 wrote:Is it a street or a race car?

Was it dynod with mufflers?

How in the hell did you get a 65 coup that heavy?

It's a street car and it just has lots of doo-dads. Dynamat, stereo, stock seats, etc. And that's with driver weight. He could use a week or two of a diet   

If you uncap it bring your jet kit with you and fatten up the carb. I was just jacking with you about the cowl scoop, it's a good looking and running Stang.

windsor wrote:Thanks, guys.  I think we're looking at the exhaust at the moment to see if that's a cork.

We know the heads are small, but it still made the power it made so should be a bit faster.

Checking the exhaust and gonna flow the fuel system and go from there.

Keep the ideas coming if you think of anything else.

Oh, and another thing, I want to say this wasn't meant to disparage Len or UCC. I actually recommended my friend to go to him for a converter because I thought that was the issue. I'd still do the same and my friend has told me that Len's customer service has been great!  

No offense taken at all. I am just as curious as everybody else to figure it out. I did speak with Bob yesterday and went over a few things with his data. There is a lot of good info here and I am positive that you will get it going in the right direction soon. I will be here and will help out whatever way I can.

Thanks, Len.

We hope to figure it out. I'm sure we will...... Eventually.

If you look at the dyno sheet you can see it's running out of head. The hp peak is flat almost 1000 rpm wide And the exhaust is hurting it too. Also the converter is way below the torque peak, but with it being a street car he may want it that way. That Canfield head is more at home on a street 351 than a 408.

Also was it on the dyno with the exhaust as it is now or open headers if not the same the tune is off.

Weekend before last I tuned a S-10 355 flat top flat tappet truck down from a 7.50 to a 7.05.

I'd say the ET & MPH match the dyno sheet.to the car weight.

like said need a better engine top end w/cam, but then it is a street ride

Spectre Ram Air (slows down without it)

This is one thing that stands out that needs addressed ^^^^^.
I do agree that the heads are on the small side too !
I do believe that you have a 11.00 to a 10.90 that can be tuned out of the existing combination.

good luck!

I think the 2.5" exhaust system is holding up the show. The car could probably benefit from a bit more gear as well but you're sacrificing the whole "driven on the street" thing of course. That air filter comment is curious. Is hood clearance an issues?

Also, I am suspect that changing the converter that drastically made no difference to the ET. 60' wasn't affected? If not, something sure is holding it back. What's the fuel system consist of?

I am not exactly sure on his fuel system info. He needs to get it flowed, but I do know he's only running an older Holley black pump and some pretty average sized lines.

DanH wrote:I'd say the ET & MPH match the dyno sheet.to the car weight.

like said need a better engine top end w/cam, but then it is a street ride

I'd think with the power it made it should be a few (maybe a couple) of tenths and MPH better than it is....that's what we're trying to find. But, hey, it is what it is!

I hope they are not the stock lines? If so they are likey 5/16", and are too small. Sounds like a good place to start checking, for issue's.

No, not stock lines.

We're going to try to drop the exhaust first to see if that does anything. That's the easiest check.

Taking the exhaust off is worth a try. A 140 GPH Black pump and a 3/8" line should be OK. I still think the 3.89 gears are good, and going by the dyno sheets 3.70's might even work for the 1/4 mile. 4.0" stroke makes for alot of torque, and is not real high reving just like the 400M Ford is. Keep after it, you will get there.

windsor wrote:I am not exactly sure on his fuel system info.  He needs to get it flowed, but I do know he's only running an older Holley black pump and some pretty average sized lines.

'

Correction: Blue pump and 1/2" fuel line.

Well at least you have a good size fuel line.