88'camaro305TBI

iTrader: (2)

Does anybody know if GM used headers and what kind of intake system to dyno the 350 that they are selling for $1,200?

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Mods:Hooker Aerochamber 3" exhaust, gutted kitty,
March 2 piece underdrive pullies, smog pump gone,;these two made a very noticable difference.
14x4 K&N open air element filter-the best mod so far
Eibach springs with KYB's all around.
Appearance: Harwood cowl hood, Z-28 wing, painted black(7/20/00)-original color was light blue
*All these mods were made this year
Stock Options:117,000 miles on motor, 5spd, TBI, 305, T-tops
Run a best of 16.7 @85mph with traction problem. Have to try again sometime.

IrocManiac

GM usually puts exhaust manifolds on their cars and as far as I know they always have at least here in the last 20 years or so.

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TPI 305,
Gutted airboxes,
gutted MAF,
K&N filters,
Corvette Servo.
14.9@93mph

"Speed kills, wanna live forever, drive a Ford."

Scrams84Z

I don't know what they used, but CHP dyno'd this engine at 239 HP and 324 lb-ft torque at 4,100 rpm's with cast-iron exhaust manifold and a stock aluminum Q-jet intake manifold. With just an Edelbrock performer intake manifold and 1 5/8 Hooker headers, it made 265 HP and 350 lb-ft of torque. If you want to see the effects of various mods on this engine, check out Chevy High Performance July 2000 article "Goodwrench Quest Part VIII" They go through various mods, and dyno'd the engine after each mod so you can see which mods made the most power. In the end, with the mods plus a blower, they made 471 HP. Before the blower, they made 416 HP

812MANY

Can someone please scan in those issues and post a link or email them to me?

I've got one and it HAULS! But there are a few things I'm not sure about (tuning wise).


Thanks,

John

(J812MANY@aol.com)

swervin ervin

John,

I have the complete series on my site. Be forewarned it is a Chevy truck site but that doesn't matter as long as you see what you are wanting to see.

Edit! It might help if I give you the link to it.
http://www.shelby.net/mgervin/chp.htm


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Mike
Chevytalk.com Moderator

[This message has been edited by swervin ervin (edited October 12, 2000).]

BadSS

Variety is the spice of life. This one loads a little slow,, but it's a true scan of the CHP "Goodwrench Dyno Series" http://www.aros.net/~rbuck/chp/Welcome.html

FastBroker

Now THOSE links are the best I've seen in quite some time. Thx, guys.

Vader

That's very interesting. They performed very similar modifications to their L98 that I recently did on an LT1. After analysis of advertised numbers and other dyno results for the individual mods, I calculated that my output power was at 382.4. Their dyno results proved 381 with similar compression, valve train, and head flows, and no blower. I must admit I'm feeling pretty good about my calculations. I also calculated 447.6 lb/ft of torque at 3,500 RPM, but the intake differences may make that pretty difficult to compare.

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Later,
Vader
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"Make Me Bad"
Adobe Acrobat Reader 4.0

[This message has been edited by Vader (edited October 13, 2000).]

BadSS

Vader,,

Do you use a simulated dyno program? The Performance Trend software is scary close. I had a few engines dynoed in my middle years of hot rodding,, but haven't dynoed one after the 1st year of using their software in 1992. It's just that close. I have not been off more than .2 seconds on estimated the cars et on an engine I've built since using the PT software in tandom with the Patric Hale 1/4 jr program. Mods on my own race car (not the IROC I've been having trouble with),,, and cars that I set up or tune usually come in within .1 seconds --- carbed,,, non computer controlled that is. I have not been unhappy with a performance mod in many years. Before 92,, I was pretty good with the old pencil, paper, and calulator,, but rarely got within 1 horse!!!!!!!!!!!!! Good one!!!!!

Corry

Where do you get that software, and how much does it cost/how easy to use etc...?
Corry

BadSS

Corry (and others)- Here's Performance Trends link. I use the Engine Analyzer 3.0. I've used the Pro Version, but the 3.0 version is pretty dang close and it's relatively quick and easy to use, not to mention a lot better value at $110 - the Pro version is major nice though. There are other products out there and I've had customers that brought me their $30 desk top dyno software,, and while it is a good tool and will help give you some idea of how a change COULD effect your engine, and it's a lot cheaper, it just does not have the amount of programming needed to get the low and low mid power curves close to the real thing. The EA 3.0 is off a little (not much)down low on the rpm scale,, but not like the desk top dyno (the versiona I've used anyway). So,, you get what you pay for,, and that's not intended to be a dog on the desk top dyno software - it may be hard to beat for the money - depends on how accurate you want the software to be.

Anyway,, check their sight out,, they have a demo of the software available.
http://www.performancetrends.com/

Box of Rocks

[QUOTE]Originally posted by BadSS:
[B]
So,, you get what you pay for,, and that's not intended to be a dog on the desk top dyno software - it may be hard to beat for the money - depends on how accurate you want the software to be.

Badness,
You be right on it with the "get what ya pay for" thought.

I picked up the desktop dyno AND the desktop drag programs new in the box at a swap meet last month.......for $15. Tax included.

They are off, especially down low - and get this - what they term "small tube headers", "ported heads", and a few other variables must be figured out before any of it is worth a darn.

The challenge for me was in calculating how they arrived at their variables' values. The heads were easy to figure out, the exhaust was easy..........and something was still wrong - I was not getting real world changes in HP/TQ with the dyno changes I was seeing by changing cams.

So.....must be in the cam variable right?

Yup. Bigtime. Seat to seat timing was essential to load in. If you use lift at .050, it gets ridiculous. Also, the power curve change for hydraulics is okay, but the solid profiles come out way too optimistic, and the roller profiles are a joke (way too high)

So, bottom line?

Once you get a % correction multiplier you go backwards until you find one sweet spot. Take a real-world dyno run from the pages of a magazine, list the exact parts used, and load 'em in.

I now call a 1-3/4" header a "small tube" just for the desktop, and I call a 195cc head with 2.05 valves and ported/polished runners a "pocket ported" head...but hey - it works.

I've got this little hummer to + or minus 1% on HP at the right RPM, and + or - 2% on Torque.

I'm currently looking at the % correction/addition to RPM for lower torque values, and it looks to be about 10% of max RPM that needs to be added to RPM readings below 3000.

In other words, if the desktop says 350 LB.FT. at 2500, and it says 450 at 5,000,
then take 10% of 5,000 (500), and add it to 2500.

I've found it's pretty accurate. The above example corrects to 350 FT. LBS. at 3000 RPM, with a max of 441 ft. lbs. at 5,000.

Golly geez.......my time is too cheap - I mean ferchrissakes.....I coulda' just bought the freekin' good program.

BUT NNOOOOOOOOOOOOOOO...........

Always shopping those bargains man. Got to.
Schizz is too expensive these days. Hey !!

Just did valve seals and full injector service on the L-98 car - for a total cost of ehhhh...'bout $250. Shop wanted $900 to do it.

So, I took the money I saved and scored a new compressor and a scad of tools, along with a new parts washer. ($380 total, MORE SHOPPING)

NYA AH AH, BOR becomes "Mr. Thrifty".

BOR

Black Beauty

that was a good series in CHP. im planning the same setup only with a holley 850 double pumper as opposed to the 750cfm. and a random tech hi flow cat, flowmaster 3 inch catback, and k&n xstream air filter(open element) . and boring and/or stroking it first. hoping to get 450 naturally aspirated.

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Rick
90 Camaro RS 305 TBI
350 on the way!!

FastBroker

Use the 750... 850 for only 400-450hp is toooo much, unless of course you are drag racing it only and not daily driving at all... That 740 can support 450-500 hp with proper tuning.