LXS

I've got the March issue of Super Chevy, and I really like the 383 TPI build up they did on pg. 57! It's basically a sleeper, down to the stock plenum, intake, and heads! I know those are pretty much the bottle neck of "optimum performance", but being that I'm in Cali, I'm leaning towards this to keep it smog legal Only thing that might give it away is, a bigger throttle body, and headers...something I could live with! This is a quick run down of the build, let me know what you guys think...


Chevy 383ci TPI:

CHP stroker kit; .030 forged pistons, rods, and cast crank. Pistons, combined with the stock heads (which are ported) give a static C/R of 10.6:1. Cam is a Comp Cams XR264HR cam that offers a .487/.495 lift split, a 212/218 duration split, and a 110-degree LSA. 1.5 roller rockers were also used. Heads (motor was yanked out of a Vette), were ported and finished up with a competition valve job. Flow rate was up to nearly 260cfm. The factory TPI lower intake was also ported, along with the plenum. Factory runners were tossed in favor of TPIS runners. Throttle body was also a TPIS piece, but size was not mentioned...most likely the 58mm T/B. Computer was controlled by a FAST XFI management system, and an MSD distributor. It was dyno'd at 458hp/534lbs.-ft. torque!!!

So, what do you guys think? Yay or nay? TIA!

Edit: I'm planning install this in my '91 Camaro, and use it as my DD. Must be smog legal....or at least until I get my tags LoL I'm not planning to do this right now this instant, but I am looking towards getting it on

LoneStar666

if you build that motor id put a little bit more duration/lift in the camshaft since its a 383 and will have heads that flow a lot...

rjt76

that hp # seems 100 high

LXS

Is there anything that you guys would do differently? Keep in mind, I'm going to try to keep this smog legal....or at least until I get the tags LoL I've had it parked since '00! I bought the car, drove it maybe 2 or 3 days, then spun a crank bearing! I yanked the motor, tore it apart, but was never able to buy the parts to put it back together. I've tried a few times to save up, but something has always come up to prevent me from saving the money. I'm going to be selling my '95 Suburban (has a 6" ProComp lift kit rolling on Super Swamper TSL/Radial 36s if anyone is interested ), and I'll be using the money from that to get the parts I need!

JulieGTA

There's a few local people who have gone 383...hopefully they can give some input.

Sharper minds than mine are working on that bottle neck...

Street Lethal

iTrader: (16)

Sounds a little off. Did they state where the power peaked, and what it actually averaged throughout? Even with the 110-LSA, that's a very mild camshaft for a 383, regardless of the lobes being used....

Street Lethal

iTrader: (16)

^ actually... I'm so used to quoting RWHP even since I started posting on the LS1 boards. If their quoting FWHP than that might be more believable. I'm very curious now, think I'll pick up that issue myself, today.

3rdgenZ

iTrader: (1)

they're talking about fwhp #'s. HDformula has made 400RWhp with the SLP runners and the comp cam XFI 286 > 63-08-466-8 Comp Cams XFI Camshaft, 218 / 224, .570 / .565 113 LSA, Very Strong mid range powerband. Headers, exhaust, computer tuning recommended.

but with the LTR setup i personaly would use a smaller LSA. check this out
> http://store.summitracing.com/partde...8&autoview=sku <
or
> http://store.summitracing.com/partde...8&autoview=sku <

the one with 112 LSA would be more user friendly

LB9GTA

iTrader: (1)

Holy, that's alot of flow for a set of stock heads that are ported. I think that number is a bit high.

Desk top dyno is 404fwhp@5000 and 512tq@2500

Someone is fluffing those numbers.

jmiller

I'm in the land of rediculous smog rules too , CA.
3 years ago I put together and installed a 383 in my IROC. It passed smog just fine. It's a daily driver with plenty of power and no loss in MPG (22mpg freeway driving at 75-80 mph). I've owned my IROC since 1993 and have driven more than 200,000 miles with no problems, the 383 has about 25,000 miles on it.
All these parts are CA carb approved except the heads. But the smog guys can't test to see if the EGR is really working because it's buried under the plenum!!!! I went with the non-heat riser version AFR heads because I didn't want 74cc chambers!!!
My build:
forged crank & rods internally balanced
4 bolt main late model block
190cc AFR heads (no heat riser version with 68cc chambers 10.5 to 1)
KB pistons
TPIS big mouth manifold
TPIS large tubes
TPIS ZZ9 cam
52 mm TB
roller rockers 1.5
edelbrock headers
random tech. cat

89Nighthawk

I"ll believe a magazine test's dyno numbers before desktop dyno.

Remember it's a matter of matching components to get more out of the sum than the individual parts.

LB9GTA

iTrader: (1)

If the stock heads that are ported and can flow 260cfm, why would anyone want to buy aftermarket?

BTW, my afr 195 eliminators that are cnc ported only flow 260cfm at 0.55 lift intake.

Sounds too high.

Kevin91Z

iTrader: (1)

If you're keeping the stock heads, then save your money on the crank and keep it a 355. The stock heads will restrict it so bad you will not get the power you want. Apply the money towards Trick Flow or AFR Eliminator heads instead. Get yourself a set of Dyno Don's 1 3/4" headers, have me tune the chip, and you'll make 330-380 rwhp like the rest of us in the SoCal club.

LXS

Sounds like a good idea Keving! How much do you charge for the chip/tune?

Gramps

iTrader: (1)

ya know, back in feb when i got the issue (im a subscriber), i posted the article. its kickin around in the TPI forums somewhere...anyways...we started talking about it and soon enough figured that it was not NET HP, but GROSS HP. its still impressive, but if you calculate for net hp, the numbers are more realistic. somebody also emailed them about the cam they used, they said that it came in that box but never confirmed that it was as advertized because it was used.

im planning on building a 383 this summer, but ive got some money to spend so im going for gold with my motor (ya gotta pamper the things ya love most). if i were you, id go with some aluminum heads, something cool so you can please your buddies, but nothing too big, 195's without the porting are plenty. i hope you'd also planned on redoing the rest of the drivetrain, your torque converter will need upgrade, along with that measly 700R4, and maybe go with some better gears like 3.42's or 3.27's if you like highway driving. sorry if you have a manual, i know nothing about them.

good luck
Gramps

LXS

It's kinda hard to tell by looking at the graph, but, it looks like 458hp@6000rpms and 534lbs.-ft@4000rpms (roughly).

LXS

I've got 4.11s in it, and I LOVE driving on the freeway! LoL I don't have too much money to spend, but I'm hoping that I can squeeze just enough to get a decently quick motor going I know the converter is one thing that'll really bite me in the *** when it comes to buying one! Not looking forward to spending all that money, but I do know I'll need it for optimum performance...beides, once I feel the rush, it'll be worth it when I'm grining from ear to ear!

Gramps

iTrader: (1)

it sounds like you got yourself a good setup, with that kinda gearing, youll have an awesome 60' launch. try to select a cam based on what you think the powerband will be, then match your converter. im going to get the engine dyno'd before i purchase the converter, so i can get the one that fits my application, but you can probably imagine a low stall torque converter just because its TPI.

rjt76

I would love to see those stock tpi parts make that gross 458hp with the parts they used. seems like they are leaving something out of this equation?
Is this really possible and how?