kevinc

Baseline run, showing pig rich ~10:1 air:fuel ratio at the wideband O2 sensor:

290.1 hp @ 5400rpm
324.5 lb/ft @ 4300rpm

Best run after tuning to ~12.9:1 air:fuel ratio:

306.2hp @ 5300rpm
335.6 lb/ft @ 4300rpm

For comparison, previous best run with the modded TPI setup:

287.5 @ 4500 RPM
367.5 @ 3300 RPM

Definitely some extra power in there, my compliments to Holley on a great new product.

rezinn

I'd like some graphs, could you post the best tpi and the best stealth ram ones?

kevinc

The engine specs and dyno data can be found in the link in my sig. I'll add the dyno graph from today's run in a few minutes.

Ray87Z

Hmm, will be interesting to see if you actually improve your 1/4 time or not, HP is actually down pretty good until the TPI system peaks at 4700rpm ish. Should be really interesting, thanks for the dynos.

BTW, the GMPP H.O. heads you mention are Al L98 Vette heads right?

Oh yeah, what exactly kinda tuning were you doing on the dyno, just AFPR tweaks or do you have DFI of some kind?

What are your initial seat of the pants feeling, car overall feel quicker, slower, what?

f-crazy

iTrader: (-1)

the stealthram is definetly good for some hp but id take the 30 ft pounds over the 20 horse

Ray87Z

Wonder if it needs some more tuning, I was a little shocked by the only 20 hp gain as well with this engine setup.

BuckeyeROC

So wait, these dynos are both with a HOT cam? And the only change was from TPI to Stealth Ram? I would think the HP numbers would be higher with that cam.

f-crazy

iTrader: (-1)

yea thats what i was thinking...it kinda makes me wanna stick with a ltr setup for the torque..is care less about 20 horse id take that 30ft pounds n e day of the week

Acceld Z

Don't look at the peak numbers, look at the averages and the area under the peaks.

f-crazy

iTrader: (-1)

id love to look at the curve but there isnt a graph....tpi and the stealthram both make a pretty flat torque curve but id still take the tpi torque

Acceld Z

He has a graph posted on his website.

NOSFEDGTA

Something does not make sense though. His Tq figures seem incorrect. I have seen a few dyno tests with stealth rams and not one of them lost as much tq as he did so early. This is very wierd.

Drew

kevinc

The only thing that changed from LTR to Stealth was the intake. We started out very rich as mentioned, ended up close to 12.8:1 air:fuel and made 302hp. That last run the engine got up to 240degF and the wideband data shows lean, but it picked up 4hp. Go figure.

The heads are GMPP aluminum L98 heads, straight out of the box with no porting or polishing.

Bear in mind my LTR setup wasn't stock. 52mm TB, Accel SR base, hogged out plenum and runners were making good power.

kevinc

Glad to share the data. I was tuning the main VE table in the 90 and 100 KPa rows, and the Power Enrichment fuel and spark tables. I left the fuel pressure constant at 44psi.

The Vette heads were bolted on straight from the box after cleaning, no porting or polishing. This was a mistake and is most likely the bottleneck in my induction/exhaust systems. I'm happy with the power both my LTR and Stealth Ram make, but know the Stealth has more potential than my 163cc intake runner heads can use.

The stealth definitely felt stronger above 4000rpm and the dyno tells the story between 4800-5600. I'm having trouble keeping my engine cool during hot restarts and this started after the Stealth went on. Most likely a steam pocket forming in one of the heads...after a hot restart the temp shoots up to ~240deg, then falls back to ~190degF after a "burp" into the reservoir tank. As long as the engine's running, it's fine.

For now, the LTR will go back on. I'll likely upgrade heads after this season, at which time I'll add a rear coolant crossover to the Stealth just to make sure this problem is killed. It's a great intake, made good power, can't wait to see it with a set of AFR 190 heads under it!

rezinn

Thanks for the graphs Kevin. I did some analyzing of the graphs you gave and came up with some average torque and power results which might surprise you.

tpi torque 334 power 252

stealth torque 316 power 237

This is not exact calculations because I don't have the software to analyze the data here, but it should be somewhat close. These figures are from 2200 to 5600rpms.

Grim Reaper

That's funny. When I look at your "best" with the StealthRam, I see an AF Ratio at 13.9:1, not 12.9:1.

Also, did you try different Spark Advance?

kevinc

The engine was running ~240degF on the run I posted...made more torque at the hotter temp but the same fuel table ran lean as the WB-O2 data shows.

We did 11 dyno pulls in all, the last three were all in the 302-306hp range and I was working on fine-tuning the PE table.

cobrakiller1989

iTrader: (1)

what cam are you running in your car? im just wondering if it is more suited for the TPI or SR or maybe about even

BuckeyeROC

He's running a HOT cam, which should be slightly more suited to the Stealth Ram. I'd get a bit bigger cam with a Stealth Ram though.

cobrakiller1989

iTrader: (1)

geez, and i was thinking about getting the hotcam for my stealth ram...maybe ill go bigger

Jza

Go bigger. I'm going with at least a 232 for my SR.

Guest

The TPI would have its rear handed to it by about .3/2mph just off those graphs. Thats using 2 different programs, and my own thing in excel I came up with near the same.

Low rpm torque isnt all that.

TRAXION

A 232 cam (if we are talking hydraulic roller) is way too big for the Stealth Ram and a 350. I am running a 230 cam with my 350 MiniRam setup and it borders on being big. A great cam for the stealth ram and a 350 would be a 224 cam. Maybe the CC 224/230 cam? IMHO, anything much bigger than that will be out of the Stealth Ram's powerband.

Tim

BenDoe91z28

I'm running a compcam 224/230 cam with my stealth ram and could wish for a better cam. It idles a little rough, really starts to pull about 3000 rpm and i shift about 6300-6400. Also gets good gas mileage.

Matt87GTA

Interesting..... I would have to bet that those POS Edelbrock headers aren't helping you any either..... I also noted the 13.9 AFR...... hmmm....... Seems to be more on tap.

Boxeat2469

I'm glad I didn't buy a stealth ram. I'd rather have the raw torque of the TPI over the few extra HP at the top end.

Matt87GTA

Well, I've been on both ends with a fully-siamesed setup on mine currectly and a true LTR on it before that. The huge rush of low end torque was nothing but a liability when it came to actually trying to race (or come out of corners). I mean, I won't deny that it was a total blast to be able to just smoke the tires whenever I felt like it and all, but the broader power band is the way to go, hands down.

Scott 88 GTA

I created a new graph from two of Kevin's to really show the difference between the two setups. The HSR really flattens out the powerband, and definately pulls a lot harder up top. I like the shape of this curve much better.



And, just for comparision, here's Kevin's HSR plotted against a friend of mines stock '02 SS. These are very similar.

Acceld Z

So in theory, the HSR falls in between the Miniram and SuperRam as far as power curve signatures go? From what I remember, it's runner length is similar to the LS1. I'm also surprised that none of the HSR owners have been contouring the walls of the runners where they meet at the top. I don't know if that flat section is very condusive to air flow.

Jza

I'm sorry. I should have mentioned that that was for my 383.

kevinc

The Edel headers aren't the best available, but my cyl heads are the most likely suspect. They're unported, unpolished, straight-from-the-box GMPP 'Vette heads and the intake ports are kinda nasty with casting bulges and general roughness. 163cc intake runners...puh-leeeze. I should have laid off the crack-pipe when I was ordering, or at least whipped out the dremel and cleaned up the intake and exhaust paths.

Take a look at the 405hp GM is making with the Z06 engine using nasty-looking header-like manifolds. Unequal length, shorter primaries than most headers, etc. Good heads, good intake tract, the right cam, good downstream exhaust flow, and good software making righteous power.

BadSS

Some of us have

http://community.webshots.com/photo/...47148835zXuLDD

Acceld Z

Lol, yeah, that's what I meant

NOSFEDGTA

Just to add some info on the stealth ram i had mine flowed. It flowed 350 cfm!!! All I did was port match it to a 1256 felpro. whcih matches am afr 190cc head.

I am very curious to see what mine is going to do. Mine should be done in about 3 weeks. 355cid, balanced, forged 9.82:1 comp, afr 190s, stealth ram, comp cam 224-230 dur 533-540 lift. headman 1 5/8 headers, 2800 10in stall. Custom prom by Dave Emanuel. I am hopping for some 12.50s all motor and mid 11's with the 150 shot...

Drew

e-man

NOSFEDGTA when you flowed was it just the base or the plenum,base and T-body?

NOSFEDGTA

I flowed the base alone. It flowed 330 then with clay to radius the inlet it flowed 350...

Drew