Holley Stealthram - Is it legal? What's it cost? Where do I buy it? - FAQ Updated 10/07/2002 - Alternative Port EFI Intakes - Third Generation F-Body Message Boards

Brad · 06-19-2002, 11:43 AM

In the interest of stopping all the repeated questions because people are too lazy to search, I've started this thread.

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Q) What is the Holley Stealthram?

A) The Stealthram is a new EFI manifold manufactured by Holley. The manifold is based off of a tunnel ram carb manifold with a cast aluminum plenum which bolts to the top. There is a complete EFI retrofit kit available which includes the manifold, ECM, and wiring harness, although the more popular option is the manifold only. More can be seen at http://www.holley.com/HiOctn/WhatsNew/WhatsNew.html

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Q) Will the Stealthram pull and make power past 6 grand?

A) Do you mean, "Can the Stealth Ram support a horsepower peak above 6000 rpm?" If so, my answer is...I think so. I haven't seen any dyno results from anyone who's using good heads and a big enough cam to say for sure, but we know that it won't be choked as bad as factory TPI or even the SuperRam at 6000+ rpms.

If you bolt a stealth ram on an otherwise stock TPI motor, the answer is HELL NO! It won't fall flat on it's face after 4500 like the TPI, but it will still make less and less power as you go above 5500 rpms. (even though it dynoed 63 more hp at 5200 than a stock TPI 350 motor)

That doesn't mean the Stealth can't flow up there. It happens because the factory heads and cam are not capable of peaking up there. I don't know exactly what the highest rpm the factory heads and cam are capable of peaking at, but I guarantee you that it's below 6000.

Don't get me wrong here. The "rolloff" of power above 5000 rpm's will be much less dramatic with the Steatlh Ram than with the factory TPI on ANY motor. My point is that it's your whole combo that determines your power curve.

Example:

My big 224/230 duration cam @.050 with .503/.510 lift will make peak horsepower at about 6000 rpm's with some great heads and the Stealth Ram in a 350. In a 383, it would be at about 5600 rpms.

So will it "keep pulling and make power" above 6000 rpms? Well that depends on what your definition of "keep pulling and making power" is. Power will start dropping more and more as I rev it above its peak. Optimum shift point may be around 6200-6500 to put the engine back higher in its powerband after I shift into the next gear.

Now if I had a huge solid roller cam with like 250 degrees duration and .600+ lift, that thing would want to peak above 6000 rpm in a 350 for sure. Would the Stealth Ram allow this high peak to occur? I don't know dude. I don't think any of us know exactly what its limitations are yet.

All I know is that its a hell of a lot better than any of our alternatives for a bad *** intake manifold for the price. And that's why Holley made it. - esams

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Q) What are the part numbers for the Stealthram?

A) The manifold carries Holley part number 7540 or 7540P (for the polished version). The fuel rails carry part numbers 534-185 for the version with a non-adjustable fuel pressure regulator, or 534-186 for the fuel rails with an adjustable fuel pressure regulator. The adjustable fuel pressure regulator is the same part used on Buick Grand Nationals and is available septerately under part number 512-503.

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Q) Does the Stealthram include the throttle body?

A) No.

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Q) How much does the manifold cost?

A) Prices will obviously vary according to where it is purchased, but expect to pay ~$280 for the unpolished manifold, ~$600 for the polished manifold which is a special order item, ~$175 for the fuel rail kit, and ~$100 for the seperate AFPR if you do not order the kit with the adjustable regulator already provided.

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Q) Where can I buy the Stealthram?

A) Many suppliers do not currently list the item in their catalogs or website. However, ThunderRacing currently has the Stealthram listed on their site at this link. Remember: ThunderRacing is a paying advertiser for this site and without their support, we would not be here. Please remember this when deciding where to purchase parts for your vehicle.

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Q) Is the Stealthram smog legal?

A) No. The Stealthram is based upon a carb manifold which was never designed to be smog legal, and as such the Stealthram is not smog legal. It does not include an EGR system, and at this time it does not appear that Holley will ever make the manifold smog legal. Keep in mind that the affordable price of the Stealthram is based upon the fact that Holley was already manufacturing the carb based manifold and therefore were able to significantly reduce manufacturing costs by reusing existing parts and not worrying with smog certification.

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Q) Will the Stealthram clear my stock hood?

A) The Stealthram is approximately 2 inches taller than the factory TPI system. It will not fit under the factory Corvette (C4) hood, but it will fit under the factory thirdgen Camaro/Firebird hood with some clearancing. If you are not comfortable with cutting/denting your hood and you do not desire to purchase a new fiberglass hood for your vehicle, then you should look at other options such as the Miniram or Super Ram.

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Q) Will the Stealthram clear my strut tower brace?

A) No.

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Q) Does the Stealthram fit my heads?

A) The Stealthram is drilled for both early and late model SBC heads so it should fit most applications except Vortec. However, the ports are designed for a Felpro 1205 gasket. Larger ports will not fit.
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Q) Does the Stealthram work with late model Vortec heads?

A) No.

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Q) Can I use a stock TPI throttlebody be used on the Stealthram?

A) Yes

(I'm not sure about the mounting hardware though, i think i've seen it said that it takes the regular metric TB bolts, but someone else say no they were standard thread like the mini ram. )
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Q) Can you use the stock fuel rails on a Stealth Ram.

A) No.

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Q) What else do I need to install a Stealthram?

A) Doug Flynn lists these parts (your requirements may vary)

-Used a 85 Camaro Carbureted upper radiator hose (Dayco 71028) (trimmed the ends back)
- Use a std. small block Chevy waterneck (Mr. Gasket PN 2661)
-Two 1/4" x 1/8"NPT straight barb fittings (rear of intake, MAP sensor and other items, I run only one line to MAP)
-One 3/8" x 3/8" NPT straight barb fitting (rear of intake other vacuum items)
-One 3/8" x 3/8" NPT 90 deg. barb (goes under plenum, used for brake booster)
- 2 feet 1/4" vacuum hose
- 2 feet 3/8" vacuum hose
- (1) 5/16" compression fitting to -6 male AN
- (1) 3/8" compression fitting to -6 male AN
- (2) 3-1/2 foot -6 line with female hose ends. Goes from inlet and outlet to fuel stock fuel lines which are cut from underneath car, the two compression fittings are installed on the stock fuel line.
- (3) 1/4" vacuum plugs for EGR solenoid and throttle body
- (1) large clamp

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Q) What fuel line fittings do I need to adapt the stock hard line fittings to braided hose?

A) http://www.holley.com/HiOctn/ProdLin...A/9894DBH.html The 9894DBH & 9894DBJ are the ones needed for the stock hard lines the other two are used if you want to come off the stock rubber lines in front of the manifold.

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Q) Is the Stealthram any good? How much power does it make? What kind of quarter mile time increases should I see?

A) Holley has yet to release any "official" horsepower numbers for the manifold, but Doug Flynn from Holley has done some dyno testing and seen impressive increases. The manifold was tested on a 92 Z28 with the only changes from stock being the Stealthram, a 58 mm Holley throttle body, and a 3" cat back exhaust. The dyno numbers were:

RPM Stock HP Stealthram HP Diff
3400 190 175 -15
3600 200 188 -12
3800 209 198 -11
4000 210 204 -6
4200 212 210 -2
4400 213 223 +10
4600 214 234 +20
4800 210 240 +30
5000 198 239 +41
5100 184 238 +54
5200 174 237 +63

To read more about the Z28 and this dyno session, see http://www.chevytalk.org/forums/Foru...ML/000534.html. Regarding quarter mile times, at this time no one has come forth with actual timeslips to verify performance differences. However, given the dyno numbers shown, expect to see a very reasonable gain.

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Q) Would the Stealthram be any good for my 305?

A) The numbers being tossed around for the Stealthram are 300 cfm per runner (or per cylinder). This is much more air than 99.9% of all 305's could ever use. Unless you are running a large cubic inch, heavy breathing engine, it is recommended that you stay with the stock-style TPI system. The torque loss from the Stealthram can be made up for on a large engine with no loss of driveability, but the average 305 would probably be close to unstreetable when running this manifold. This, however, is speculation as no one has actually swapped a Stealthram onto a 305 at this time.

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Q) How long will it take to get my Stealthram once it is ordered?

A) Product seems to be catching up with demand, therefore it should not take long.

Brad · 12-04-2002, 09:26 PM

Due to recent... um.. circumstances

I am unsticking and unlocking this thread. Anyone who asks a question that is in this thread, however, has obviously not performed a search and will be slapped with a large trout.

tazmision89 · 12-11-2002, 12:31 PM

how is it that if it were to go on the 305 that it would be unstreetable??

I would like to order one for my 305 but I need more clarification on this.

Thanks.

e-man · 12-11-2002, 06:41 PM

Its that with the stealth ram a 305 will most likely lose enough low end torque that it will be a dog on the street.But 3.73s and a higher stall converter would help.Since nobody has posted having one on a 305 yet and if you have the money($450 isnt that much if you look at the other prices of other TPI stuff) try it.If it doesnt work out it shouldnt be hard to sell.

68firebird · 12-15-2002, 07:31 PM

How will I have to modify my computer for this to work on my car? 1987 GTA w/ 88 L98

e-man · 12-15-2002, 08:02 PM

Any time you do any mods you should reprogram the chip so you can get the most from them.Get your car dynoed with a wide O2 sensor and you'll see how rich the stock programing is

68firebird · 12-15-2002, 08:06 PM

and how would I go about doing that and how much would it cost? Also, is it relativly easy?

BikertrashDude · 12-15-2002, 09:30 PM

I want one.
what aftermarket hoods will not fit with the stealth ram?
is a low 2" cowl good enough?
biker

e-man · 12-16-2002, 07:26 AM

Biker you have camaro so it should fit with out a problem on my formula I just had to cut brace out in the center of the hood. 68 firebird go to the prom board and read the top Thread.And dont be scared It looks like a lot of stuff but you only mess with is fuel and timing starting off.

89Formula350WS6 · 12-18-2002, 12:38 PM

I am strongly considering the StealthRam since my hood got damaged and I plan on getting the original design Ram Air hood from ASCD. I know that my stock TPI is holding me back when though the rest of my L98 is still stock too.
Will post detailed results for others to see.

$200 for used SLP runners+
$300 or so for a used aftermarket base+
porting the plenum

VS.

around $600 total cost invloved for the StealthRam swap.
Looks like a No-brainer.

Since my car only has some bolt-on mods and is MAF equipped, will I have to burn a new chip/or have one burnt to realize any gain? So far I have never even seen my car's computer and would like to keep it that way as long as I can't tell that there is a drivablity/performance problem.
I'll get into the chip burning later on.

Anyone care to make a guess as to what kind of HP & ET gains I would see?

CrazyHawaiian · 12-25-2002, 08:20 PM

I read through all of the links on this thread. On the ChevyTalk.Org boards one member asked about the torque losses. Someone replied saying you only loose 9.7 ft/lbs @ 3400 rpm (torque x rpm /5252=hp sooooo! he lost 9.7 ft lbs of torque at 3400rpm and gained 63.63 ft HP at 5200rpm, in effect he gained torque and hp from 4400rpm and up and the worst he did was loose 9.7 ft lbs at 3200rpm ). Can anyone else verify this? With all those HP gains I would assume you'd loose alot more torque than that.

xanax · 12-25-2002, 10:28 PM

the stealth ram completely wakes a stocker up. it pulls LT1s with no problem, 6000rpm+ is nice. but i have a t56 and 3.42s though. its even still making good power when shifted at 6100 with ARAP with only a modified injector constant, no other tuning. i love it and would never go back to TPI, next is big runner heads and a huge cam for me, either that or 4.10 gears then the heads+cam swap.

CrazyHawaiian · 12-26-2002, 06:54 AM

Wondering if TPI Strut Tower Braces will fit. Dosnt look like it.

xanax · 12-26-2002, 10:38 AM

i noticed no torque loss. it seems to pull harder from a stop to me because it is easier to keep traction off the line with no spin. once i hit the top half of first gear the car just slams you back in your seat and your constantly pushed back until throttle is let up. no tpi wall, thats for sure. im sure you could have a stb with a hood that has more room like a cowl or possibly an SS hood. the thing i like about the stealth over the LT1 that was my deciding factor was not having to use a remote thermo housing. just a personal preference, but id rather have my thermostat where its supposed to be.

Scott C · 12-26-2002, 01:44 PM

I'll let you know if I lose any torque once I get mine running in a few days...

Eats5.0's · 12-27-2002, 10:14 PM

Scott C.. yes yes.. please post how well that works for ya.. Trying to figure out the intake side for my 383 project, and that is still in the research department. Wonder how well it would respond to my Paxton...
BTW, sweet looking engine..

age · 12-27-2002, 11:01 PM

Crazy Hawaiian,

I wouldn't really worry about the T5 too much. I (and a few other road racers around here) have T5's behind a stout 350 motor. Of course, I don't power shift, or drop the clutch at 5000rpm. If you do get the T5 (and if you feel adventurous), there is a rebuild kit online that has a couple of parts that strengthen the T5 (I forgot the site, I'll have to look it up).

If you do decide to get the Stealth Ram and fab your own STB, could you also post some pics? I just ordered mine and a "custom" STB will of course have to be made (I'll post mine up if it's done earlier than yours).

BTW, for all you Canadians out there, I got my HSR for $440CDN (after tax and a 10% Boxing Day discount); it works out to about $275US net total, but you don't have to pay for shipping/handling and whatever else our gov't "taxes" us on. I'm still waiting for the fuel rails to be ordered, but If you work out the conversions and such, it's cheaper than ordering from the States.

Allan · 01-08-2003, 09:11 PM

Scott C, I am also interested in how that intake works out on your car. Looks like your specs are almost identical to what mine is going to be - but still debating on getting the stealth ram now, or wait until later since the cam, headers and engine work is still ahead and all that costs a little $$$.

Your setup:

'92 RS - ZZ4 10:1 350 - Edelbrock Performer heads - XR269HR cam - Stealth Ram - BBK 52mm TB - Accel 24# - Holley AFPR - Walbro pump - SLP/Jet-Hot 1-5/8" headers - Catco 3" cat - Dynomax 3" catback - Hughes 2500 stall converter - TransGo 700R4 - 1LE driveshaft - Comp Eng. SFC - LS1 rear w/Auburn Pro posi & 3.42 - Hotchkis/BMR/Spohn suspension

Here are my plans (as of right now):

'88 IROC - L98 9.5:1 350 - Stock L98 Cast Iron heads with bowl, porting, 3-angle valve job, milled to 62cc - XR269HR cam @ 114 LSA (custom grind) - ZZ9 PROM - Stealth Ram - Stock TB (for now) - AC 22# - Holley AFPR - Hooker Ceramic Coated 1-5/8" headers, No cat - Dynomax 3" catback - Dacco/Detroit B29DB 2400 stall OEM vette TC - Rebuilt 700R4 w/ Corvette Servo, .500 Main boost valve, .296 Intermediate/Reverse boost valve, 1LE driveshaft, SFCs (undecided), BW Posi 2.77:1 rear.

'bout the closest I've seen to what I plan on doing to my ride is yours. Now I could opt for the 10:1 flat-tops which would be about 10.2:1 (a bit too high for my taste on pump gas). Also, I was provisioning for a supercharger in the far future which is why I elected to get the XR269HR cam at a 114 LSA grind. But whether or not I do it, I still think that a 114 LSA will give me more of a computer savy cam.

Also, if I get the stealth ram immediately, I would want to also opt for the larger TB - which = more $$ up front. Anybody wanna donate to the "Get Allan's Car Back on the Road Fund?"

68firebird · 01-09-2003, 10:26 PM

what is the best head/cam combination to go with the stealth ram? come spring time there is about a 99% chance I will buy the stealth ram for my basically stock L98. Also, a good converter to go with that setup would be what? thanks.

choko · 04-07-2003, 06:30 AM

I have a Vortech Super Charger on the way.. will there be any thing that will get in my way if i get the Stealth Ram?

Lunkan · 04-27-2003, 04:23 AM

How many of You guys use the Holley SR? I´d like to see some pics of Your setups. I just got mine, and there´s alot of "holes" in both the plenum and intake that I really don´t get a qlue of.

Christos · 07-27-2003, 03:37 PM

Is there no way to fit some sort of EGR on the manifold as a custom job?

bigals87z28 · 07-28-2003, 10:58 AM

how is this not a sticky anymore... brad posted it... it should deff. be a sticky.

EDIT: please slap me with a trout.... totaly missed that post after the FAQ... and why was this taken down? ahh i dunno...

Christos · 07-28-2003, 01:22 PM

Well, I am going to find out on emission laws here in Colorado, then see if I can find anyone who has fit an EGR on this manifold, or if it can be done.

If not, *cough cough* maybe the emissions stations out here won't exactly check to see if it's functional, and maybe i could pass emissions anyway without it.

I just hate to spend tons on a new engine, only to not be able to drive it out here because it won't pass visual/emissions.

anesthes · 07-29-2003, 08:12 AM

I'm curious also if the vortech fits it..

I'm also curious if it would do anything on a blown motor, over a slprunner, edelbrock intake, ported plenum TPI setup.

-- Joe

CrazyHawaiian · 07-29-2003, 08:25 AM

I will be replacing the TPI intake on my blown 91 z28 with a StealthRam pretty soon here. I will be doing before and after dyno sessions so I'll let you guys know how it turns out.

anesthes · 07-29-2003, 08:51 AM

I'd appreciate that.. What are you running, ATI? 2 inches is a lot.. Gonna have to mess with he plumbing...

If you netted something crazy i'd love to know.

-- Joe

mrr23 · 07-30-2003, 08:27 PM

have a website dedicated to the stealthram. www.stealthram.com if you have one and would like a link to your site from it, then email me with it. any and all info is appreciated. i'll keep adding as i go along.

mrr23 · 01-02-2004, 10:22 PM

message board is up over at www.stealthram.com