Dave_85

iTrader: (1)

I want to modify the Stealth Ram to fit a 85 Vette. I don’t want to modify the plenum since there seems to be issues with it. From Davis’ Z28 web site his photos look like the HSR is 10in high. Holley publishes 10 ¾. Is it really only 10in high. The Lingenfelter Super Ram is 9 3/8in high and that fits in the Vette. So my plan is to mill 5/8 out of the Stealth Ram base and relocate the plenum mounting screws to the front and back of the two banks of intake ports and screw up into the plenum from the bottom.

Is the plenum width smaller than the width between the fuel rails. Since I am going to move the plenum lower into the base it will need to fit between the rails. Can anyone
measure the total height, width of the plenum and the distance between the inside of the fuel rails.

Thanks

Brett H. - 89GTA

There are C4 guys out there running a StealthRam with a custom plenum. I don't remember where they got it, but I bet the Firebird guys would be interested too.

http://www.diabolicalperformance.com...web-plenum.jpg

brutalform

This is Third Gen.org, not the Corvette forum.

Dave_85

iTrader: (1)

Floor guy

OUCH! Easy Brutal, we are all pals here. No need to bash the vette guys. They don't bash the f-body guys on the vette forum. We all bleed bow tie blue.

brutalform

Your right Floor...Im sometimes narrow minded.

Brett H. - 89GTA

This topic is also of interest to Firebird guys who don't want to cut the hood bracing to fit a StealthRam (like me).

Twilightoptics

I would suggest milling the plenum/base flange down... and tap the screw holes longer if needed.

I would NOT want to be screwing anything UP into the plenum. Honestly thing of how difficult to bolt that, it will be? And if you mean to bolt it from underneath the manifold upward...... what if a screw falls out?

I've had to take the plenum off several times... and you typically need the plenum off to install the dizzy cap, even the distributor.

But yes, there is an outfit that makes a special slanted shorter plenum. Look them up before doing any milling that could lead to vacuum leaks.

brutalform

I said I was narrowminded didnt I?

Floor guy

I can just feel the love now!

davel98

I'm intrested in doing this for my 'vette too. However, I'm not sure if you can mill the top of the manifold base (if I'm reading you right) because it expands outward, and the plenum holes and manifold holes would not align, and you can't mill the bottom of the maifold because it obviously wouldn't align with the heads/block.

The only feasible think I could see is cutting and sheetmetal the plenum, unless I read your statement wrong.

Twilightoptics

It does spread outward, but the bolt holes are still going to be in the same place. You might have to get bulk gasket to make your own with a slightly bigger diameter.

DeepSouth_454

https://www.thirdgen.org/techbb2/sho...ht=stealth+ram

Custom plenums mentioned in this post are no longer for sale...however, apparently some new designs are in the works from "Grumpy".

I believe one issue with the Holley most don't seem to mention is their inability to match up to aftermarket heads with bigger/larger runner ports. Most I hear of them being run with are 195cc heads.

Twilightoptics

Good post, I didn't even think about the following "NO you cant mill down the HSR base BECAUSE it causes the following problems

no room for the water neck/radiator connection

throttle body linkage interfearance with both fuel rails and connections

fuel rails hit throttle linkage bracket mount

sensors in manifold hit throttle body

heater hose to throttle body connections hit water neck and sensor connectors

fuel rail mounting bose is weakened

plenum mounting bolt hole bosses need to be extended into ports or new ones welded on

injector port angles would also need to be changed

fuel lines connector tube would also need to be changed

plenum would need to be longer requireing differant air cleaner connector "

Dave_85

iTrader: (1)

The grumpy post about a new plenum is almost 2 years old. I emailed grumpy, nothing yet.

As far as the problems go I think I can get around everything.
The one problem listed I don't get is 'injector port angles would also need to be changed' Why?

I was planning on adding a spacer to angle down the TB and move it away from the fuel rails.

Can anyone take some measurements.

And yes I feel the love.

Brett H. - 89GTA

It seems like a custom plenum wouldn't be too big a deal...get a section of extrusion and modify it. I've been considering this since I have access to a Bridgeport at work. Weld up one end and you're in business.

Dave_85

iTrader: (1)

I was looking at taking two channels and welding them together.
I seems doable.

Back to the original post.

Can anyone take some measurements?

FSTFBDY

iTrader: (33)

You can to mill both the PLENUM TOP and the Plenum Base. You just have to watch how much you take off.

I did it on matts intake, and he ran it in his GTA.



Id have to get ahold of him to see how much more room he had but as I recall he didnt have to cut the brace out. and he didnt have any problmes with anything else..

. Would it fit under a vette hood?? I have no idea..

Everything is TRUE and No leaks. The parts were done on a Mill and I made sure everything was true/flush/level.

Dave_85

iTrader: (1)

Can you find out what the total height was after the mods.

FSTFBDY

iTrader: (33)

I will try. as I said I did it for somebody. I will have to get ahold of him.

FSTFBDY

iTrader: (33)

roughly 9 1/2 inches from bottom of the intake to top of the plenum.

and Im sure I could have milled more off and been safe...

Dave_85

iTrader: (1)

Thanks. I think I only need 1/8 more and it should fit.

FSTFBDY

iTrader: (33)

You should be fine then.

because all I did was the top of the plenum and the Top surface where the plenum mates to.

You could easilly go more on the top of the plenum or all sides of the plenum and be fine then.

davel98

Now I have a question:

Dave_85: How much clearance do we have under our hoods?

And TPl383: Did you have to make a new top for the plenum, or was that a stock penum you milled down? Is there that much metal that is able to come off of a stock HSR plenum??

-Dave

Dave_85

iTrader: (1)

The Super Ram is listed as 9 3/8 high so I think if you get the Stealth Ram down to 9 3/8 and make an angled TB spacer it should fit.