new single plain intake design...

http://forums.corvetteforum.com/showthread.php?t=1256942&forum_id=48

Interesting...seems like it would work good for big cubes & high rpm. What do you guys think?

Short side on that elbow is a killer.

Bret

Short side on that elbow is a killer.

Bret

But could you make it work with out alot of pressure drop?.

best part about that is its built for a TPI head wont do no good on a LT with out other work to make it bolt up.......


might as well just call bret tell him your plans and let him do a conversion for you

LPE/Accel make an elbow just like that ready to go. Ive posted on it before if you search my name plus accel elbow

I have seen those Vette boys take a carb intake and bolt a "box" onto the carb mount with bolts that go all the way through, and bolted a throttlebody on the front.....ran 10's on motor if memory serves.


David

LPE/Accel make an elbow just like that ready to go. Ive posted on it before if you search my name plus accel elbow
thread (http://web.camaross.com/forums/showpost.php?p=3381327&postcount=8)

Thought I'd help out.

I have seen those Vette boys take a carb intake and bolt a "box" onto the carb mount with bolts that go all the way through, and bolted a throttlebody on the front.....ran 10's on motor if memory serves.


David


More then one is in the 10's with Jebs old intake I think the newone wil be even better. The reason for him making the intake and the reason it is short is the fact it was made to be used in a C4 with the stock hood. We have limited clearance and all of the after market intakes other then mini-ram and SR wont clear.


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I'm thinking that it can't be much better/worse than any of the other elbows or elbow type plenums out there.

best part about that is its built for a TPI head wont do no good on a LT with out other work to make it bolt up.......


might as well just call bret tell him your plans and let him do a conversion for you
How much does the intake and conversion cost? Also when should one need or look into getting one?

I'm thinking that it can't be much better/worse than any of the other elbows or elbow type plenums out there.


I compleatly agree unless you have a C4 corvette. The hoods on these cars are big $$$ and most don't want to hack a hole in the hood so that is the real atvantage of Jeb's setup. There are plenty of single plan intakes out there with the elbow that will work on most cars just not the C4.

Is the reason for an elbow like this just because of hood clearance?

Well it could be worse but I'm not exactly sure what the effect would be. My thinking is probably in line with Bret's when he mentions the short side radius. My intuition says it should be as large as possible for a gentle transition into the main plenum but what do I know. Never tested it one way or the other.

sseeya,

Yep, it's all about hood clearance.

-Mindgame

Well it could be worse but I'm not exactly sure what the effect would be. My thinking is probably in line with Bret's when he mentions the short side radius. My intuition says it should be as large as possible for a gentle transition into the main plenum but what do I know. Never tested it one way or the other.

sseeya,

Yep, it's all about hood clearance.

-Mindgame

I figured it must be, because there are several aftermarket companies that make 1000+ CFM, 4 barrel throttle bodies that bolt right up to a single plane intake manifold. Holley, Accel, and Ron's Fuel Injection are three that come to mind.

Funny I still cant find one of these elbows from Holley, Accel or Rons. I've seen a picture of the Accel one and it seems to have the same problem as this sheet metal one.

Bret

Funny I still cant find one of these elbows from Holley, Accel or Rons. I've seen a picture of the Accel one and it seems to have the same problem as this sheet metal one.

Bret

Bret, I wasn't saying that Holley, Accel, and Ron's made elbows. I don't know whether they do. I was saying that if hood clearance wasn't an issue, they all make throttle bodies that directly bolt up to a single plane manifold.

Yeah, throw Wilson in there as well. They have some of the best made parts I have seen yet. Ron's is up there too.

BTW just had a guy ask me about a HSR for his LT1 in a early Vette... everything work on your setup?

Bret

Yeah, throw Wilson in there as well. They have some of the best made parts I have seen yet. Ron's is up there too.

BTW just had a guy ask me about a HSR for his LT1 in a early Vette... everything work on your setup?

Bret

Unfortunately, financial constraints and not enough time did not allow me to do anything but get it installed. However, it is on the motor and in the car and everything works. Winter has arrived in the northeast now, so the race car is in the garage. Hopefully I can get it on the dyno for a retune and to the track once spring gets here.

Good just wanted to check in with ya.

Bret

Any thoughts on front to rear cylinder imbalance with a forward facing throttle body ? I've got a HSR on a L98 type 398 (.040" over 350 block). After a dyno session I noticed the plugs were rich from the front to lean in the rear. Got me to thinking about trying a single plane intake, or extending the plenum forward.

It's funny you should mention that. When I had Bret convert an HSR to work on my LT1, that was a major concern of mine, since the HSR has no IAC channel like the LT1 intake. I expressed that concern here and was told by several people not to worry about it. Unfortunately, I haven't been able to get my car on the Dyno for a tune, so I don't know if it's going to be a problem. Personally, I think it is going to be a problem, and I am also thinking about possibly switching to a single plane in the future. My race car has a Corvette big block style cowl induction hood, and I have cut out part of the cowl, so I should be able to use a four barrel style throttle body without an elbow.

Good thing I put the MAP plug in in the middle of the plenum then.

The IAC though can't really do to much about.

Bret

I'm curious about this killer short side radius (SSR).

If you have a 4bbl TB on the intake, doesn't the air still have to make a sharp turn to get into the TB (although, the air has the "choice" to come from 360º around the TB)?

How is this bad SSR measured? CFM?

I lost 30rwhp when I pulled off my air filter and let the MAF "dangle" around on the dyno. My guess is that the the extreme suction of air into the TB was intereferred by the perpendicular air "trying" to make an instant 90º at the edge of the MAF. Just a hunch.

Just like Brett's sig: Theory is great and all, but can anyone offer real world advice?

"I don't like it" and "It doesn't look good" scare people into not trying things. Not saying that some caution sholdn't be excercised, but isn't the whole idea of keeping a stock hood a compromise? Heck, the stock motor is a compromise. Life is a compromise.

I'd like to offer some real world numbers as I put together my SP intake (dubbed: project monoplane :)) using a little logic, a little theory, and a little dinero. Probably looking at a month before it comes complete, but I promise I won't sell it before I verify it doesn't make any power :p.

Ryan

Just to add a little bit more deductive reasoning...

The stock intake draws air in and the air must make 8 near-90º turns inside the plenum, right? In a single plane, teh air flow is much more gradual and smooth. So, is one single "hard" 90º turn more disruptive to airflow than the LT1 intake?

Runner length aside, a single plane seems like it would "direct" the air much more smoothly after the flange.

So....smoother flow inside the intake, or smoother flow outside the intake? I might be assuming way too much :o.

Ryan

Ryan,

I think you are missing something with how the flow works where it works.

If all the air for the motor is coming over that SSR in the bottom of the elbow then it IS going to have trouble feeding and flowing into the front 4 cylinders.

If you have a better more gradual radius on the SSR then you can feed the front cylinders more and faster.

A sheetmetal intake or a tunnel ram intake like the LT1 basically is, is fed on a 360° area, and one of it's huge drawbacks that causes it to flow badly is the hard radius on 3 sides of the port entry and a non existant one on the shared wall. Just because the air flows in thru that intake does not mean it does it very well. FWIW the air doesn't make a staight line from the TB to the runner and turn 90°.... you need to think of it backwards. The low pressure in the cylinder is sucking air thru the valve, down the port, thru the intake runner, out of the PLENUM, thru the TB and MAF/Aircleaner.... The plenum is basically a storage tank to store air that the cylinders need once the valve opens.

Bret

It would be interesting to see what a short height SP, with factory restrictions (TB, stock hood) could make in a street car.

I asked "altjar" what he gained with his swap, but he has not gotten his combo tuned up to where it could be. If everyone that asked the "what LT1 stroker parts work best" question had an idea of all the different crap you have to go through to make a solid motor (that made any power), they would buy an LS1. Most of them will, are, or already have done ;).

Ryan