Re: 61 Plymouth twin turbo longram project
[Re: Streetwize]
#1564351
01/19/14 04:15 PM
01/19/14 04:15 PM
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Joined: May 2003
Posts: 6,566 Downtown Roebuck Ont
Twostick
Still wishing...
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Still wishing...
Joined: May 2003
Posts: 6,566
Downtown Roebuck Ont
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Quote:
To me the issue is not as much the port cross section as it is if the long runner has to carry the fuel the whole way, if you can put the injector nozzles down by the intake valve (as close as you can anyway) all you have to worry about is moving the compressed air way down the rifle barrels, if you have to carry AIR and FUEL then a good bit of that runner column's volume and cross section (about 7.5% at a 12.5:1 ratio) is going to be displaced by the fuel where you really would rather have that much more room for AIR. The other thing is an injector will help atomize the fuel which will vastly improve the torque since you have a really bad short side in a conventional RB head.
The ultimate might be a standard port Chapman Stage VI head on a low deck block, this way you have a bigger valve, and a much better short turn radius all in a package that will allow the manifold to bolt up. The heads are still out there and they flow like mad (more than a lot of max wedge heads out there) for a 260CC port volume (which helps you as well) AND a standard port window that will mate up to your manifold. That turn radius and injector might make you another 80-100 lb/ft AND carry the torque curve way on up there, so you have a real win-win. That thing is begging for a 470" low deck with about a 6.8" rod (~1.23" CH piston with a d dish)
Those are a 2 piece manifold so they will fit both B and RB engines if that opens up any other head options.
Kevin
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Re: 61 Plymouth twin turbo longram project
[Re: Twostick]
#1564352
01/19/14 09:37 PM
01/19/14 09:37 PM
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Joined: Jan 2003
Posts: 9,876 Weddington, N.C.
Streetwize
master
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master
Joined: Jan 2003
Posts: 9,876
Weddington, N.C.
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The arc over the valve covers might be an issue if you raise the port window in the RB, the long horn intakes didn't have a whole lot of valve cover clearence to begin with.
As for standard port window flow (and MW too) the Chaps are tough to beat.
I'm just brainstorming a combo I'd like to try if if were mine. The 470 with an early 230 cold weather '71 casting (they're sill out there) would be a bit more durable in the main webs for all that mega-torque in a pretty big vehicle.
It'll be Awesome any way you do it though
Last edited by Streetwize; 01/19/14 09:41 PM.
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Re: 61 Plymouth twin turbo longram project
[Re: TRENDZ]
#1564353
01/20/14 02:24 AM
01/20/14 02:24 AM
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Joined: May 2006
Posts: 441 duluth mn.
dragula426
OP
mopar
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OP
mopar
Joined: May 2006
Posts: 441
duluth mn.
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Take a look at my dyno sheet. This is a 470" engine with an unported weiand tunnelram on a set of 906 heads. Running 14psi with twin te44s on regular old pump gas and no intercooler. This is chassis dyno, so the converter does play a part, but this is what the tires are seeing.
wow! that's good power... and right around the rpm range we think this one will make power and torque at too! got any pics of that thing?!
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Re: 61 Plymouth twin turbo longram project
[Re: davenc]
#1564357
01/23/14 10:51 PM
01/23/14 10:51 PM
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Joined: Jan 2005
Posts: 2,540 Milwaukee WI
TRENDZ
master
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master
Joined: Jan 2005
Posts: 2,540
Milwaukee WI
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Quote:
Trendz,
I understand you would not put a race converter in this, but any converter that would not kill the engine in gear off boost is not going to stall anywhere near 2300 RPM behind the monster you built. I have a factory 440 converter (mopar designated it a 120K) and it instantly flashes to about 3300 RPM behind my NA 400/470 with 490 RWTQ. You may not notice this on a chassis dyno, but with the weight of the vehicle, particularly a old barge, it seems all that energy is just going to go into heat at the converter.
If you had a converter that would stall at 2300RPM with 900 ft/lbs, I don't see how the motor could run in gear off boost (guessing 20 ft/lbs).
Like I said, You need to unlearn things. I never said anything about "stalling" the converter. The truth is, on the trans brake, you can drive right thru the converter if you don't do some power limiting with engine controls. A nice tight large converter works excellent for MOVING a very heavy car with very low numeric gearing and extreme levels of torque. Will it make heat? Yeah. but not like a small race converter. Think of diesel converters and the narrow bands they have to work in.(mines tweaked and it's still governed to only 3200) I have a 1st gen cummins with a goerand non lockup converter.It is as tight as you can imagine, and it is not harsh when going into gear, or does it idle any different than a stocker. I would have loved to try it behind that 470
"use it 'till it breaks, replace as needed"
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Re: 61 Plymouth twin turbo longram project
[Re: TRENDZ]
#1564358
01/23/14 11:54 PM
01/23/14 11:54 PM
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Joined: Jan 2003
Posts: 9,876 Weddington, N.C.
Streetwize
master
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master
Joined: Jan 2003
Posts: 9,876
Weddington, N.C.
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True, but a large diameter converter isn't inherently more efficient just because it's larger....and every converter has an efficiency curve.... that said some Nitrous converters behind very quick ET'ing cars are actually so tight the motor alone won't hardly do a burnout on dry pavement without at least a single stage hit. There are guys here that probably FORGOT more than I'll ever know about converters but with a Turbo you are adding torque to the powerband at a at a rate of rise far beyond that of a Normally aspirated combo, the reason/justification for a looser converter is essentially to side step the soft part of the curve and allow the vert to hit the tires more like that of a clutch whose RPM is matched to at or near the torque peak. With blowers/spray/turbos and even a lot of big torque strokers I think there are many people who (whether they #! realize it or #2 would admit to it) have over-stalled/flashed their combos and effectively side-step a lot of Meaty powerband they could be put to use to propel the car. The long rams are going to make more torque sooner so maybe you want to run a turbo with a tuned HOT side to bring in the boost, the VE on this motor with this intake is going to be so high at low RPM and low throttle position you're not necessarily going to be moving a lot of exhaust gas, and as a result the turbos may not spool up as fast as you think. I'm much more concerned about the lack of cross section for the HP you can make on the boost (on paper), as I said to move the fuel all the way through the runners is going to take up a lot of volume I'd rather have reserved exclusively for boosted AIR and then let the injector just hit the valve with the needed fuel.
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Re: 61 Plymouth twin turbo longram project
[Re: davenc]
#1564360
01/24/14 08:48 AM
01/24/14 08:48 AM
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Joined: Jan 2005
Posts: 2,540 Milwaukee WI
TRENDZ
master
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master
Joined: Jan 2005
Posts: 2,540
Milwaukee WI
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I hope you didnt take my "unlearning" comment wrong. I didn't mean it as any type of insult, and it wasn't directed at anyone. It was more a description of what I was going through when putting this together. Anyway, I need to give you some history here. This thing was put together some time around 1992. Nobody(ok maybe not many people) were building stuff like this yet. I didn't have a target torque curve, and honestly didn't have much knowledge on this stuff. I started with the standard stuff to make a "go fast" car. gears, converter,etc.. I had the most complicated 12 second car on the planet. The car was fun, but not fast. One day I decided to fix my weak posi diff. I wanted to drive the car while I was repairing the diff, so I slapped in a 3.23 "open" rear 3rd member. I drove the car and found it was doing exactly what you describe, but once the car was moving, it felt stronger. I had a factory stock converter laying in the garage, so I put it in. I drove the car and got a huge on my face. I litterally welded the diff up and went to the track. The car went in the high 10s. I started looking for a tighter converter. Found a place in town that built me a winnebago(rv) converter. That thing was awesome for awhile, but gave up after a year or so. Anyway, incremental changes eventually lead to a different top end, cam, turbos etc.. in the pursuit of a faster car, and the stump puller engine eventually evolved into a more traditional race style motor and power curve. I sold the car in 2006. It was running high 8s at 3700lbs driving it to the track(and back home most of the time )
"use it 'till it breaks, replace as needed"
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Re: 61 Plymouth twin turbo longram project
[Re: TRENDZ]
#1564361
01/25/14 01:23 AM
01/25/14 01:23 AM
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Joined: May 2005
Posts: 598 NC, USA
davenc
mopar
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mopar
Joined: May 2005
Posts: 598
NC, USA
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Trendz,
I try not to take anything personally. I mostly come to this site to learn, and hopefully I have helped a few others here as well. Please don't take my question as disrespecting what you have done. I'm still waiting to get my junk to the track and hope for high 11s. No expert racer here!
The first converter I had behind my 400/470 was a MP175K unit I had around, and it felt like mush behind my motor. That was annoying so I swapped in a factory 440 converter and I love the responsiveness at a roll, but it is awful rough going into gear, and it really lugs the motor down at idle, making carb tuning more difficult. Somewhere in my future is another converter swap!
This is why I pay attention to "high" torque combos and the converter, particularly for mostly street cars. I really want to get it right next time, and want to fully understand how best to balance the in-drive idle characteristics, the responsiveness, and the ability to actually put power to the ground (as opposed to tire smoke, or massive slippage). I know the torque curve and converter need to be well matched, and I'm curious how others have done it. Your case is an extreme one, but sometimes there are good lessons to learn at the extremes.
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Re: 61 Plymouth twin turbo longram project
[Re: TRENDZ]
#1564362
01/25/14 01:55 AM
01/25/14 01:55 AM
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Joined: Feb 2003
Posts: 4,953 Houston, Texas
TheOtherDodge
master
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master
Joined: Feb 2003
Posts: 4,953
Houston, Texas
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Quote:
Quote:
Trendz,
I understand you would not put a race converter in this, but any converter that would not kill the engine in gear off boost is not going to stall anywhere near 2300 RPM behind the monster you built. I have a factory 440 converter (mopar designated it a 120K) and it instantly flashes to about 3300 RPM behind my NA 400/470 with 490 RWTQ. You may not notice this on a chassis dyno, but with the weight of the vehicle, particularly a old barge, it seems all that energy is just going to go into heat at the converter.
If you had a converter that would stall at 2300RPM with 900 ft/lbs, I don't see how the motor could run in gear off boost (guessing 20 ft/lbs).
Like I said, You need to unlearn things. I never said anything about "stalling" the converter. The truth is, on the trans brake, you can drive right thru the converter if you don't do some power limiting with engine controls. A nice tight large converter works excellent for MOVING a very heavy car with very low numeric gearing and extreme levels of torque. Will it make heat? Yeah. but not like a small race converter. Think of diesel converters and the narrow bands they have to work in.(mines tweaked and it's still governed to only 3200) I have a 1st gen cummins with a goerand non lockup converter.It is as tight as you can imagine, and it is not harsh when going into gear, or does it idle any different than a stocker. I would have loved to try it behind that 470
Bingo! i have a 3000 PTC converter and can leave at any rpm on the transbrake. One time i forgot to put in a 2step chip and the logs showed 5100 rpm leave!
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Re: 61 Plymouth twin turbo longram project
[Re: dragula426]
#1564366
06/17/14 07:32 PM
06/17/14 07:32 PM
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Joined: Jul 2005
Posts: 1,954 Blairsden, CA
Triggerfish
top fuel
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top fuel
Joined: Jul 2005
Posts: 1,954
Blairsden, CA
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Quote:
it's nice to see iit on the ground again!
WA,WA,ZAT!?... BEYOND COOL. Keep up the good work...
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Re: 61 Plymouth twin turbo longram project
[Re: ScottSmith_Harms]
#1564368
06/18/14 11:11 AM
06/18/14 11:11 AM
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Joined: May 2006
Posts: 441 duluth mn.
dragula426
OP
mopar
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OP
mopar
Joined: May 2006
Posts: 441
duluth mn.
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Quote:
First of all I LOVE your build! But, at the risk of upsetting the masses, I find that the turbo tubing being crossed over the top of the intakes hides those beautiful Long Rams too much, was other routing considered?
yeah they do cover the intakes, but it was tough trying to route them cleanly, have them symmetrical, and still have them joined (like a balance tube) the tubing, valve covers, and block will be painted green, the long rams are polished, and i'm hoping they stand out more once everything is painted & put together. thanks for the nice words!
Last edited by dragula426; 06/18/14 11:13 AM.
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