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To much flow ? Not enough Velocity

Posted By: 70dusterjohn

To much flow ? Not enough Velocity - 09/01/18 03:12 PM

Just like it says . Had the heads and intake max port well without making then water sprinklers and now the car comes out real lazy then picks up. I have tried new msd box, crank trigger, moved the timing around, this is the second converter, with a third on its way(ati but had it reworked) my 60ft is way way way off .. running 1.70 but had a high mph of 141. I don’t know where to go from here. Is the intake to big for my comb ? I’m at a loss right now and don’t want to think I spent all that money for nothing for the heads and intake. And help would be great. Thanks John



https://youtu.be/DD7VwgIT6go
Posted By: MR_P_BODY

Re: To much flow ? Not enough Velocity - 09/01/18 03:33 PM

What rpm are you leaving at.. you might need to
advance your cam to get back into your power
range.. have you checked everything from when
you pulled your heads.. sounds like something
is off with a 1.70 60ft.. a decent street car
does that good
wave
Posted By: 70dusterjohn

Re: To much flow ? Not enough Velocity - 09/01/18 03:41 PM

I agree, I have checked torn it apart and checked . I’m a foot brake racer . So hard idle .
Posted By: Cab_Burge

Re: To much flow ? Not enough Velocity - 09/01/18 06:11 PM

Years ago when Bob Mazolini first switch his old SS/DA car to SS/BM modify car with a 411 C.I B1 motor in it, he had a 6000 RPM converter in the Powerglide for the first run, it was real lazy in the 60 fts. and ran 10.30 at 142+ MPH, he swapped the converter to a 7200 RPM for the next run and the car went 9.35 at 148.+ MPH with no other changes boogie work
That motor was 411 C.I. with a 4.500 bore and what ever stroke it needed to make 411 C.I.
My message is the motor needs to be ran in its power band work
IHTHs thumbs
Posted By: 70dusterjohn

Re: To much flow ? Not enough Velocity - 09/01/18 07:15 PM

Thanks cab, our ati was about 5,700 but was still to tight, so I sent it out for another 1,200 I hope that gets me closer ..
Posted By: FastmOp

Re: To much flow ? Not enough Velocity - 09/01/18 07:19 PM

It will be faster but it looks like your going to need more launch rpm and carb work
Posted By: Thumperdart

Re: To much flow ? Not enough Velocity - 09/01/18 08:00 PM

Originally Posted By FastmOp
It will be faster but it looks like your going to need more launch rpm and carb work


Agree, more volume doesn't necessarily guarantee more "power" till you do the needed changes to extract it just like a big cam, you need more gear, vert, higher shift points and MAYBE bigger carb etc.............. beer thumbs
Posted By: 70dusterjohn

Re: To much flow ? Not enough Velocity - 09/01/18 08:22 PM

I know I need carb work but it’s hard to do when the car isn’t running anywhere near what it should. I have a 4.30 in it now and I’m shifting at 7,500. I know a 56 or 89 would be better just not in the cards right now .
Posted By: MR_P_BODY

Re: To much flow ? Not enough Velocity - 09/01/18 08:33 PM

Try advancing your cam so it will lower the RPM
into a range your engine can deal with.. or
change to injection so you only move air..
but I doubt you want to change now
wave
Posted By: polyspheric

Re: To much flow ? Not enough Velocity - 09/01/18 10:04 PM

I agree, advance it (if you have the intake valve P-to-V clearance) may show you something.
Posted By: dvw

Re: To much flow ? Not enough Velocity - 09/02/18 12:30 AM

Mine has pair of pretty big pair of -1s. Foot braking it's been 1.24 60ft. 727, 4.10,10.5Wx31,6000 rpm fall back on the shift. 1.70 60ft sounds like a stator/converter sprag issue.
Doug
Posted By: max_maniac

Re: To much flow ? Not enough Velocity - 09/02/18 04:30 AM

Do you have a lean bog from the carb that is driving the bad 60ft???
Posted By: 70dusterjohn

Re: To much flow ? Not enough Velocity - 09/02/18 12:50 PM

No I’ve tried to raise the shooters and jet to no avail..
Posted By: sgcuda

Re: To much flow ? Not enough Velocity - 09/02/18 04:31 PM

Originally Posted By 70dusterjohn
Thanks cab, our ati was about 5,700 but was still to tight, so I sent it out for another 1,200 I hope that gets me closer ..


Something just isn't right. That is going to put your launch rpm just 600 rpm less than your shift point. I think a 5,700 rpm launch should be good enough for much better 60 ft. than 1.70's. You need to look in another direction. Are you sure you aren't leaving in second gear?
Posted By: tboomer

Re: To much flow ? Not enough Velocity - 09/02/18 04:35 PM

A long shot here...Is the shifter cable adjusted properly? work
Posted By: 70dusterjohn

Re: To much flow ? Not enough Velocity - 09/02/18 04:57 PM

Pretty sure I mean I have to shift 2 times ..
Posted By: tboomer

Re: To much flow ? Not enough Velocity - 09/02/18 05:18 PM

So if it is in neutral and you rev it a bit it doesn't creep a bit? Just trying to help here...
Posted By: 70dusterjohn

Re: To much flow ? Not enough Velocity - 09/02/18 05:19 PM

Yes it does
Posted By: 70dusterjohn

Re: To much flow ? Not enough Velocity - 09/02/18 06:33 PM

Could that really cause that big of an issue ?
Posted By: pittsburghracer

Re: To much flow ? Not enough Velocity - 09/02/18 06:49 PM

I’m going to say this about as simple as it gets. Get the car to 60 foot and the rest is all downhill from there. The first sixty foot is the hard part.
Posted By: 70dusterjohn

Re: To much flow ? Not enough Velocity - 09/02/18 07:02 PM

I’m with ya John, it’s just getting it there lol. Last year was 1.29 this year yeah hasn’t been good to me that’s for sure ..
Posted By: 70dusterjohn

Re: To much flow ? Not enough Velocity - 09/03/18 04:10 PM

Should be getting my converter back today. Then it’s pull the motor again .. this will be the 5th time this year .. but it’s easier to pull the motor than the trans .. I hope this helps some ..
Posted By: sgcuda

Re: To much flow ? Not enough Velocity - 09/03/18 05:21 PM

I don't think you're getting your converter today. It's Labor Day. No deliveries.
Posted By: 70dusterjohn

Re: To much flow ? Not enough Velocity - 09/04/18 12:34 AM

Yeah I’m driving to get it. He is local to me ..
Posted By: ProSport

Re: To much flow ? Not enough Velocity - 09/04/18 12:45 AM

I would try that new converter next and take a known good carb with you off someone else's car.
That will eliminate 2 big possibilities and hopefully fix the problem.
Try the carb after you make a run with the new converter obviously.
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