Re: smallblock modman intake..
[Re: A57_RT ]
#1227448
05/05/12 06:42 AM
05/05/12 06:42 AM
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Joined: Jan 2012
Posts: 323
A57_RT
Parts Problem
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Parts Problem
Joined: Jan 2012
Posts: 323
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Now to present day...with no spacers it felt a bit lazy until the higher rpm areas.
So I went with a 1 inch spacer and with the 1/2 inch plate kit lower rpm throttle response improved and the powerband changed.
Through reading, research, actual testing and looking at some of the chevy guys into big plenum manifolds I added another 1 inch spacer.
So with the 2 1 inch spacers, the plate kit,all the gaskets and the thick gaskets between the carb and top of the nos plate im at well over 2.5 inches above the plenum.
Throttle response is better then the oem dual plane in every aspect.
Ive a 7200 chip and it seems to want more, ive tried a 7400 chip and it was still pulling hard, would like to see what a 7600 would do.
IMO the spacers at least on a six pack setup was like night and day.
The long intake stroke (on a stroker) loves a big plenum and on a vac six pack you need to adjust to that fact that the longer stroke will aid in there quick opening compared to a 3.58 stroke.
I think its a very good multi carb intake, not sure how they stack up with a single 4 vs other single 4 intakes though.
The one thing I did not like is with the six pack one end carb is directly over the ports and one is a bit off center.
Now that I have it setup to what I feel is right for my motor its more friendly then an oem intake in every way, as crazy as it may sound I think if I put a person behind the wheel and told them it was a FI setup its responsive enough many would buy into it.
Its easy to launch on all six barrels and there is no hit to feel from a lazy set of end carbs, its instant, no transition to feel because your already there.
Running a plate kit and a fogger kit off a controller is as simple as the rest of the setup.
I angle milled the injector bosses for the foggers, removed the bosses for the non drilled magnum intake, and since indy is so hard to deal with and give very little back I machined the indy/mod man logos off, no free ad. from me.
Its late, im groggy, I have some chassis dyno numbers to go with the spacer plate changes.
Ive 3 modman intakes and several top plates for the diff carbs, if your really wondering id be more then happy to loan one out just to see how they run against other single plane intakes as all I have to revert back to is my modified oem intake and so little is on the web about the pros and cons compared to a std intake/plenum.
I play at 7000-8000 feet above sea level and this intake loves rpm, I wonder how well it would do in good air????
This is my current setup and I dont know what I could do to make it any better, its also an easy manifold to get a perfect port to head match on all 8.
Id really like to see what a single 4 would do vs the top convential? single plane.
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Re: smallblock modman intake..
[Re: moparclown]
#1227450
05/05/12 08:06 AM
05/05/12 08:06 AM
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Joined: Mar 2009
Posts: 2,467 Sydney,Australia
tex013
top fuel
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top fuel
Joined: Mar 2009
Posts: 2,467
Sydney,Australia
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A57Rt, good info i wonder if i could try some spacers on my big block dual quad modman. i gather your spacers are dual hole not open ?
Tex
New best ET 10.259@129.65 . New best MPH 130.32 Finally fitted a solid cam, stepped it up a bit more 3690lbs through the mufflers New World block 3780lbs 10.278@130.80 . Wowser 10.253@130.24 footbraking from 1500rpm Power by Tex's Automotive
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Re: smallblock modman intake..
[Re: tex013]
#1227452
05/05/12 01:33 PM
05/05/12 01:33 PM
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Joined: Jan 2012
Posts: 323
A57_RT
Parts Problem
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Parts Problem
Joined: Jan 2012
Posts: 323
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68rrman aka dashman on ebay is a great guy for any type spacer at very fair prices, if you look at his ebay site you will see and he can make almost anytihng not listed. A very nice fella to deal with. Yes the plates I use are the not open, just the holes, but here again the above mentioned could do you most anything. Actually ive plans drawn up to plum one of the 1 inch plates or possibly 3 of his singles with foger tip in the end carbs for another mod man project. Quote:
A57Rt, good info i wonder if i could try some spacers on my big block dual quad modman. i gather your spacers are dual hole not open ?
Tex
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Re: smallblock modman intake..
[Re: A57_RT ]
#1227454
05/05/12 01:52 PM
05/05/12 01:52 PM
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Joined: Jan 2012
Posts: 323
A57_RT
Parts Problem
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Parts Problem
Joined: Jan 2012
Posts: 323
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Id really like to see more of these and if some of the terms or ways of thinking may not be the norm or pc its simply Im far from an expert on this and just winged it by trial and error. Members here like sixpackgut has helped me over the years on some six pack questions and knows about plenum volume or at least is more open to talk about it then others. Tom Quad and Cab both have great input on six packs to them all. I like out of the box thinking and really got on the spacer deal after some dyno work and seeing how spacers worked on the 4bbl motors and wondered how it would carry over. At first I thought the spacers would look a bit out of place but they really dont and I plumbed the intake wide on the noids to use an oem six pack base. Yes I dog indy a bit, but who else has such a multi purpose against the grain big plenum intake both big and small block guys can use? But it is a rough casting and the main intake looks like it was cast with a top/bottom, not many intakes can take a nitrous backfire, this one wont and thats for sure, my little blow off plate is simply for the little hickups so I dont risk a throttle blade sticking or worse. Ive only popped it twice but it there is alot of fuel/air in that box and im glad its there. With my current setup being more correct, ive not had that problem but also if a cold start if it acts like its goona, I just kill the master ign switch and it cant get that far. Ive some BB pics and info I will try to post yet today, ones even a dual efi unit setup for a max wedge motor...not mine but still very nice. Here is dashmans link...he also has seperate 2300 single plates, but if you email him or call him he can do most anything at a good price imo and the parts are very good quality. http://www.dashman.net/category.html?id=27
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Re: smallblock modman intake..
[Re: A57_RT ]
#1227455
05/05/12 02:03 PM
05/05/12 02:03 PM
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Joined: Nov 2003
Posts: 5,160 Texas
dannysbee
master
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master
Joined: Nov 2003
Posts: 5,160
Texas
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Be neat to make up some 1/2" plenum spacers to do some tuneing on the plenum volume. Also top plate with carb spacers extended into the plenum with tapered holes.
Getting old just means you were smarter than some and luckier than others.
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Re: smallblock modman intake..
[Re: A57_RT ]
#1227457
05/05/12 02:55 PM
05/05/12 02:55 PM
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Joined: Jan 2005
Posts: 12,419 Kalispell Mt.
HotRodDave
I Live Here
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I Live Here
Joined: Jan 2005
Posts: 12,419
Kalispell Mt.
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I have been thinking about a mod man with a t-quad on a new hemi would be cool. I bet the big plenum makes a bigger differance with too small of carbs and 7-8000 ft elevation got to get air in there some how. Big stroker small blocks always seem to go faster with bigger carbs, some are still picking up with 1200 CFM carbs even on combos where they "shouldn't" need it in theory. A bigger plenum does the same thing to a certain extent. It makes the carbs flow more continusly instead of pulses. If you run with no plenum at all (like an individual runner manifold) you would crap yourself thinking about how big of a carb you would need, for example if you heads flow 300 CFM you would need a single venturi carb that could flow 300 CFM or about 2400 CFM total carb capacity. In theory, with a big enough plenum a single 600 CFM carb would be able to feed that same motor because it would flow %100 of the time instead of %25 of the time like it would with no plenum.
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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Re: smallblock modman intake..
[Re: A57_RT ]
#1227459
05/05/12 07:06 PM
05/05/12 07:06 PM
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Joined: Jan 2005
Posts: 12,419 Kalispell Mt.
HotRodDave
I Live Here
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I Live Here
Joined: Jan 2005
Posts: 12,419
Kalispell Mt.
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You can do either one, bigger carbs or bigger plenum. Not saying your carbs are too small but when you increase plenum it effectively does the same thing a bigger carb does and visa-versa, it allows more flow through the system. If you are running a real small plenum you tend to go faster when you add a bigger carb, if you are running small carbs you typically can run faster by adding plenum volume. It is more a matter of perspective than it is one way being right or wrong. A plenum buffers the pullses from the cylinders reaching the carbs, if the carbs can't flow enough under a pulsateing flow then a bigger plenum tends to allow them to flow continuously and act bigger. I would bet that if you were haveing hood clearance issue stacking all those spacers you could switch to a bigger cab and see the same gains.
I think the mod man intake is VERY well suited to a six pack carb set up, way better than the factory pile of junk. Fuel distribution sucks in a stock intake, they tend to run good because of the raw flow but they are not a very efficent set up, the mod man should be real good with the center carb pleced right in the center at part throttle then when the secondaries open up they dump straight down into the port totally un obstructed with no funky turns to induce fuel seperation.
I am not causing global warming, I am just trying to hold off a impending Ice Age!
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