LD85

iTrader: (2)

I know this is not a Vette forum but I thought people might want to see the insdes of a HSR Plenum

Engine Specs
406-CI
Bullet Billet Custom Grind HR cam 233/233, 284/289, .576 lift w/1.6rr's
11:1 CR
68 CC, AFR 210 heads, 300 CFM @ .600 lift
Wiseco forged Pistons, Eagle Forged Rods, Cast Crank.
Centerforce 400 Crank Flywheel / Centerforce DF II Clutch
Flow Kooler Water pump w/ Dewitts Radiator
ZF 6 speed , Hurst Billet Shifter
3.45 rear gear
Hooker 2151 cut and rewelded to clear plugs
BBK 58 mm TB
FMS 24 # injectors
MSD 8366 Small Cap, MSD 6AL, MSD 8.5mm wires
Accell Shorty Plugs
86-89,,, 165/ECM

Cut Apart to an Overall Height of 2.900 inches






Welded back together

LD85

iTrader: (2)

Trial Pre Weld





Thermo Housing Fitment



Plenum Welded

LD85

iTrader: (2)

Trial Mounted and Ready To Paint



Gonna get some datalogs, then burn some chips, then off to the track

Demon355

iTrader: (1)

That looks so much nicer than a stock HSR. I want to see some numbers...

LD85

iTrader: (2)

I always thought the stock HSR looked like a bread box, but that would not have stopped me from buying one if it would have fit under my hood.

Demon355

iTrader: (1)

It looks like a taller LT1 or mini ram kinda...I like it though. I didn't know the HSR had the bolt holes like that. Seems odd to me.

LD85

iTrader: (2)

The HSR has counterbored Socket Head Cap Screws (SHCS) Allen Head, I just machined the ribs off the top, then machined 1/4" wide groves in the top surface.

LD85

iTrader: (2)

Painted and done

WheelsUp84z

iTrader: (2)

that thing is truely a work of art, joby did something similar to his but i believe he machined the holes in the bottom on the plenum bigger to fit over top the base.

LD85

iTrader: (2)

Thanks for the kind words,

I love being able to remove the plenum when I want!

With how many corvette owners there are trying to make HSR's work, you'd think holley would just fix the stupid too-tall design.

Nice work. Came out really good.

-- Joe

Iroczracer

Were Can I send Mine To. That great looking work on that,,,,,,

Tony89GTA

iTrader: (7)

Looks good

anesthes

iTrader: (12)

Been seeing a lot of posts from corvette owners on here lately. Glad to see i'm not the only one that thinks corvetteforum is filled with retards.

Good work on the intake. Looks sick. Engine bay does in general.

-- Joe

BranZ

What kind of welder was used on it? I am assuming a Tig. What brand and model? Thanks, BranZ

88 350 tpi formula

iTrader: (9)

that has got to be the best one yet!

CC89Formula

did you ever get any numbers on this thing? id kinda like to know what it would do vs. a stock one on the dyno. how long did it take you? i might even get with you to do one for me if you want.

carguy502

iTrader: (2)

That is the cleanest HSR I have ever seen. Kool. Are there any Dyno # to see if chopping the intake did anything?

Fast92RS

iTrader: (2)

That looks great.

1989GTATransAm

iTrader: (3)

Very nice. I like the ingenuity. What's the old saying where there is a will there is a way.

GuitarJunki17

iTrader: (1)

I love it, although I am more than curious to see if this affects flow or dyno numbers at all.

I thought of something though, those bolt holes seem like they are blocking some flow. Might it be worth it to cut out those holes, block them off, and weld the bottom of the plenum to the top of the plenum? Would this make it impossible to reach the bottom intake bolts? Just an idea.

LD85

iTrader: (2)

Yeah, I am sure the bolt bosses block some flow, my AFR 210's are ported so they flow 296 @ .600 lift,,,but I really wanted the plenum to be removable,

Regarding the performance this is the result;

Miniram 1/4 mile @ 115 mph
Superram 1/4 mile @ 115 mph
HSR 1/4 mile @ 115 mph

GuitarJunki17

iTrader: (1)

So you've personally tested all 3?

LD85

iTrader: (2)

yes I have and my empty wallet is proof
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vernw

iTrader: (2)

[QUOTE=LD85;3103193]yes I have and my empty wallet is proof
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WOW! You're worse than I am!!!

I've currently got the SuperRam and am considering going to the LT1 (essentially a MiniRam as I understand it) conversion just for clearance on my strut tower brace and ease of access to injectors, valve covers, etc. plus the ease of installing and removing occasionally. Plus I've got a MiniRam for an LT1 sitting in the garage as well... (plus an Lt1 block fresh from the machine shop .020 over and various parts for it - still looking for a good stroker crank and pistons though, wallet is too light at the moment <sigh>)

GuitarJunki17

iTrader: (1)

Wow! What made you try all 3 setups? Different cars? Or did you have one intake for a while, sell it and then get a new one? It's interesting that all 3 yeilded you the same times at the track, considering the fact that the mini ram and superram are considerably more expensive than the HSR.

Nice work man.

nicksL98

iTrader: (6)

Down to a total height of 2.9" from what originally? Its a shame the guys at Holley dont listen to people when they call tech and tell them that stuff doesnt fit certain applications.(like I do.) What you did is exactly what I was working on for my 92 TA because it was either HSR or Carb. Shame i have to modify something that was already "engineered".

GuitarJunki17

iTrader: (1)

Totally.

You know, is it really necessary for the plenum to be that tall? I mean, I can only imagine that by chopping it, youd lose some performance, because if the guys at Holley were smart, they would have made it smaller to begin with to reap the profit for all the C4 owners, as well as 3rd gen owners.

If there IS no difference in performance, Holley should just manufacture that 2.9" version. This is why I am so intrigued to see dyno numbers, so to compare it to a similar setup to see if there are any staggering differences. (seems not though, as his 1/4 time was on par with the miniram and the superram).

LD85

iTrader: (2)

Down to 2.900 from 4.0"

CamarosRUS

Sexy, very nice fab work!

Shagwell

Although this is a couple months old, I too would likt to say nice work. It looks better than the original. Looks to me like it should still have plenty volume of air to handle most any engine that would be using a street minded intake.

Great Job!

LD85

iTrader: (2)

Thanks guys, I love the intake and it breathes well on my 406ci.

Once I get my clutch to stop slipping, I will have some dyno and track data.

Floor guy

Some of us Corvette guys are ok.

88 350 tpi formula

iTrader: (9)

every time I see this I think maybe I should buy that spool gun for my miller and cut mine down too.

anesthes

iTrader: (12)

You have to admit though, the majority of the folks over there are retarded.

-- Joe

MikeH

iTrader: (10)

Awesome work...

Having been thru all 3 of those intakes on your 406. Could you share your thoughts on each one? How the motor responded to each? In terms of overall power?

LD85

iTrader: (2)

Miniram was the easiest to install and used the stock distributor, but the short runner length made the car run rich since I was using a single pattern (233/233) cam, my recommendation would be to use the Miniram with 3.93 or 4.10 gears and a cam that has at least 6-8 degrees offset. When my car was dynoed with the MR, the RWHP flattened out at 5800 on up to 6300rpm, so I did not see a reason to wind the car up to 6300. My top MPH was 115.8 MPH using 3.07 gears and shift light at 5800rpm

The Superram was a PITA to install and when I went to take it back apart, there were 5-6 bolts that were loose that needed re tightened but without removing my valve covers and a couple of roller rockers, I would never have been ale to get to get to the again, waaay to much of a PITA for me. Also, the plenum rubbed my wiper motor cover so there was more clearancing, and the stock HEI distributor was less than 1/8" from the plenum. In terms of performance, my AFR 210's were too big for the Superram and the low RPM TQ was impressive but it choked at @ 5200 RPM, the car would just die in terms of performance which necessitated short shifting at @ 5200-5400rpm. My top MPH was 115.2 MPH using new 3.45 rear gears and a ZF 6 speed,,, and shift light at 5500rpm

With the Holley Stealth Ram, I had to change to a smaller distributor, bring the fuel lines in from the rear instead of the stock/front location and obviously trim the plenum height and thermo housing height. But in terms of performance the HSR is a nice compromise between the MR and SR, runner length is little longer so low end TQ is still strong and it breathes up to 6000rpm,, the top speed was 116 using the 3.45 and ZF 6 speed,, and shift light at 5800rpm

My 60' times have never been better than 2.10 due to tire spin and a slipping clutch. A new street twin this spring should fix the clutch issue and I will have to work harder on my 60' since I use street tires, it will only get marginally better,

My.02 = use the HSR unless you dont mind shifting at 5400rpm.
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mainly it is a mixed bag over there, you have the knowitalls, the wananbees, the waxers and the wingdings.

But with that said, there are a lot of decent guys there!

I am member #349 and have been there since Feb-1999 and have seen a lot of weirdness in the past years

1989GTATransAm

iTrader: (3)

The problem with the Super Ram is the TPI style intake manifold. The Edelbrock manifold and clones are better than the stock manifold.

The problem is the pinch point just inboard from where the manifold meets the head. The best JerryWho was able to get was 1.9 square inches with a lot of grinding on his Edelbrock. This is still smaller than the aftermarket performance heads and becomes the choke point.

Not good to have the choke point in the intake manifold and power suffers. The choke point should be at the intake valve. Everything upstream should be larger. This is why you can't get peak power much above 5200rpm with the Edelbrock TPI intake. Will have to see what Jerry's manifold does with his being opened up. Welding additional material would be a solution so that the area could be opened up more.

Now there is the First Injection TPI style intake manifold which does address the problem. You can hog it out to say 2.7 square inches if not more. That will get the job done. If need be for a larger motor you can always weld more material.

One other thing the First intake manifold does is it has a radius transition from the intake manifold to the head. The others are virtually flat on the floor and therefore creates an angle where the manifold meets the head. Not the best transition.

Stay tuned as I'm going the First Intake TPI manifold route. Maybe the best of both worlds. I can also adjust the runner length for the best harmonics.

rwdtech

how much better are any of those intakes compared to the LT1 intake?

LD85

iTrader: (2)

Depends on your cam and RPM limits.

Superram is good if 5500rpm is your max.

Miniram is good if you want peak HP above 4500/4800 RPM and if you rev past 6000RPM, and if you have a dual pattern cam and have 3:73/up rear gear.

Stealth is all around good up to 6000rpm.

My guess is that an LT1 intake would do fine and be more streetable.

JB97C5

I agree!!!!

TPI TERR

iTrader: (9)

,, the paint looks nice.. what did you use??

LD85

iTrader: (2)

Autozone paint, 1200 degree "Aluminum" color

with 500 degree Clear on top.

Azrael91966669

id be all over one if they came like this from the start that just looks great

thirdgenrs

iTrader: (1)

great write up and you did a great job on the fabrication. I love my HSR, very responsive and easy to work with.

Jim85IROC

iTrader: (2)

Trust me, you're not the only one. I rarely go there anymore. Every time I ask a tech question, the answer usually starts with "My mechanic said..."

LD85

iTrader: (2)

Well, I made the mistake some time @ 2003,,,,of asking about putting Coilovers on my 85,,, 75% said it was just Bling Bling....

Now there are a lot of people with Coilovers and saying, they are pretty goo.

BTW, I will be putting coilovers on a week from Saturday, ordered the parts today!

RocsRose86

mANN tHAT sURE dOES lOOK hELLA sWEET! I cANT dECIDE oN wHETER tO pUT mY tPI iNTAKE sETUP oR mY lT1 oN mY rAM jET 350....aNY sUGGESTIONS? iTS A lIL cRATE mOTOR i BOUGHT fROM a fREND. I oRIGINALLY hAD A 305 H.O....nOT eNOUGH pOWER tHOUGH! sO mAYBE u gUYS cAN gIVE mE A hEADS uP!?

rgauder

iTrader: (1)

PLEASE DON'T TYPE LIKE THAT ANYMORE!!!!

SilentBobZ28

iTrader: (5)

Where's a good place to pick up a HSR at?

onfire

LD85,

Thats great work on that intake and that whole engine bay looks real clean. It seems like its a great balance of the three manifolds.

In terms of chip tuning, did you run into any troubles with those manifolds especially the miniram??


Rabi C.