dizwiz24

What about a hogan sheet metal intake?

Ive seen f body lt1's (centrifugal supercharger) pick up 100 hP.

Why not consider one of those? Sure they are expensive, but if you were worried about cost you wouldnt be here

mnstrlt1

If money was no object, we'd all have a Bugatti....

Truth is, most of us are willing to spend money on modifications that "also" provides "the best bang for the buck". That might mean some modification, or fabrication on our end.

Sheet metal intake manifolds are ridiculously overpriced (in my opinion). I guess if I was building a $60,000 dollar motor, I'd consider one. lol

DanZ51

I don't want to drag this thread OT but Mnstlt1 posted some links and....

Who and what is this (elbow)? I think I've seen it before.


OOh, it's a FORD 4.6 elbow. (Knew I've been down this road before).

Orr89rocz

Its disapointing you c4 guys have such low hood clearance, even late model fbodies are similar. Elbows like that with such a short radius 90 deg or worse, a 90-120 deg bend into intake is terrible for flow and a huge loss factor. Almost offsets the gains a single plane could give.

precisionturbovette

The hood clearence really isn't that bad.

mnstrlt1

That is a Sullivan upper intake, on a custom lower.

http://www.sullivanperformance.com/y.../tbadapter.htm

I'm trying to post helpful information for other corvette owner's interested in a swap like this. OT, if I am imposing on your thread, please let me know. I apologize in advance.

bogor

No problem at all! I´m learning alot myself.

FrankieD

Can anyone confirm if either of these 2 setups will fit under a stock c4 hood: Accel 74140 Pro Ram intake with the Nitrous Outlet LT1 Elbow # 03-20000 or the Edelbrock Victor EFI 29785 intake with the Nitrous Outlet LT1 elbow # 03-20000

bogor

Thanks for the different suggestions how to make this work! Since I already have the Victor E and the Edelbrock elbow I will however use these but if it by any reasons does not work I now have several other options to look into.

I cannot really say if the Victor E and a Nitrous outlet elbow fit without modification. I can take some measurements on my Victor E and check distance to the inside of the hood if that helps.

FrankieD

That would be really helpful

2bar-c4

I don't know if the budget allows, but you could always go with a Toledo pro hood. I used the victor -e and made my own 90 out of 4 inch tube.

mnstrlt1

The Nitrous Outlet Elbow was mainly designed for the F-body cars, and the clearance issues they run into with the hood (very low clearance in F-bodies as you get closer to the TB position). I would imagine the profile is pretty low, if you look at my earlier posts, I provided a link to a website that shows several single-plain intake manifolds (tall ones) used in the F-body with success.

*Also - reach out to Nitrous Outlet and ask them if they have any c4 customers they can refer you to OR that have experience with various single-plain manifolds.

bogor

I have now made some more measurements and I think I have an idea how to port the intake now. I will use the CSA at the pushrod pinch in the head as a guide for minimum runner CSA in the intake. It looks like I will need to widen (from the manifold flange) the first 1-2 inch of the runner and straighten the runner slightly. I will probably focus on removing material from the roof so I won't portmatch the intake. I think getting the right angle of the manifold runner towards the head and sufficient CSA is enough at this stage.

Another thing is that the CSA of the outer runners (cyl 1, 2, 7, 8) is about 20% larger at the plenum versus the inner runners and cause the tapering of the outer runners to be alot more pronounced. I guess this will crate differences in air speed at the manifold ports but if this matters, who know? I will probably widen the inner runners at the plenum to reduce the difference in CSA.

Still waiting on getting my spacer milled down.

I checked the distance from the carb pad of the victor E to the inside of the hood: 135mm at the front bolt holes and 140mm's at the rear bolt holes. Please note that the carb pad is slightly tilted forward (3degrees I recall) but also the hood. Its difficult to get an exact distance and there are surely other factors that could create errors so keep that in mind.

mnstrlt1

That's pretty interesting info. As for clearance, I wonder if it would be easier to use clay (placed on the top of the manifold- commonly used in machine shops for piston clearance) and close the hood on it to get a better measurement of clearance?

bogor

That was how I did it.

bogor

Slowly moving forward-got the elbow welded.

Orr89rocz

I have done this alot lol when i was twin turbo with them sitting up high on valve covers they wouldnt clear the hood so i cut hood to allow housings to peer thru. I used clay to mark the hood side and show me what needed cut. Also have a cheap video camera snake from harbor freight i can snake up thru under the car and see in person whats going on.

My elbow is big. It needs a 4" cowl on a camaro to clear lol

rklessdriver

I told a poster here I would be happy to show some pics of my LTX single plane conversion and post up measurements.

The intake itself was an Edelbrock Super Victor PN 2925. The sheetmetal elbow/TB adapter is custom made... however you can see it is similar to the peice Nitrous Outlet offers.... Just comparing the pics mine appears to have quite a bit of downward angle on the TB mounting flange compared to the Nitrous Outlet one (we did this for hood clearance).

However the 28975 Victor EFI intake is not nearly as tall as my 2925 Super Victor intake - So the Nitrous Outlet adpater may fit OK under a C4 Corvette hood.

A few pics of mine.










As for measurements. You have almost 9" from the bottom of the hood (on a 92) if you measure from the top of the front china rail on the engine block.... This is right about where you TB mounting flange should be located....

You have anywhere from .5 to 1.5" additional height from the rear china rail area - So measuring from the rear of the engine block will get you into trouble because of how the hood slopes downward in the front. The further forward from the front china rail you go the less height to the hood you have.

My set up measures 8 1/4" tall - measured from the china rail on the block to the top of the TB.

It measures 16" long - measured from the rear carb flange to the end of the TB where it hooks up to the air cleaner duct.

Don't forget I have about a 10* downward angle on my TB.

I hope this helps some of you guys out.

Will

mnstrlt1

rklessdriver- great information, and I appreciate you posting the measurements. This can be valuable for anyone else entertaining a single-plain swap (like myself).

bogor- the welded TB elbow looks great!

bogor

Got my spacer and testfitted the elbow and TB



Its a tight fit everywhere (fuel rail, valve cover and hood) but with some additional grinding here and there it will fit


To get the elbow horizontal, the spacer need to be angled milled so its 16mm at one end and 21 mm on the other.