Motor Build....N/A then Boost

[Rumblin70SS]

Hey all,

Building a motor for my 93 Firehawk......going to put the 383 motor together, have it tuned, run it for a year, maybe with some spray then move up to a Procharger. Don't really care what it makes on motor, as long as it will pass an emissions test. I want to leave the internals of the motor as is, except for a new tune and fuel system upgrades when I boost it. Keep in mind its a speed density car. Looking to make 700 boosted at the motor and its mostly a street car so I want to keep all the ammenities. Might even lightly spray it to act as an intercooler. Motor is being done by a reputable machinist who has a crazy turbo car himself. I'm sure he will have most of these answers but I'm looking to learn and make sure we are on the same page.

Let me know your thoughts!

LT1 block with studs and billet mains
Callies 3.75 stroker crank, either Compstar or Dragonslayer
JE .030 dished pistons, 9:1 comperssion
Oliver rods
Stefs pan with HV pump and pickup
trick flow heads

So far, thats what we've talked over..............now here's the questions....


The big question for me.......Camshaft.......lift/duration/LS? Have no clue here. Will most like be a CC valvetrain......

Headers and y pipe.....thinking Kooks.....would like to keep the oil cooler intact if possible.

Ported intake? What's it worth in HP and can I do it myself?

Rockers?

How much work should be done to the heads for this power level? They are being bought bare and hardware added so I can go any direction.....

SC will be an F1.....will that fit without major mods?

I don't mind spending the money, cause I've seen what happens when you skimp on small parts, but I want to do it as best I can the first time.

Thanks,

Tony

[Fastbird]

To pass emissions, it's going to have to be a baby cam. But....boost loves baby cams. Keeps the cylinder pressures up especially if you go with a wide lobe sep.

If you're having the intake ported, have it ported by whom ever does the heads. It'll be matched up the best this way. Those trick flow's are LT4 designed, so either find a legit LT4 manifold, or have a LT1 welded up. Skip the edlebrock.

The heads will need to be opened up. Out of the box they're about as good as LT4 heads. Ported.......let's just use mine for an example. LE did them, they're now at 218CC runners, 64CC Chambers, and at .400 lift were moving 242CFM and crested 300 CFM @ .550 lift, on an independent bench that was extremely close tot he numbers that LE gave me. Lil' better than LT4's there.

Rockers: Comp Pro Mag, hands down.

The F1A will fit the D-1SC brackets, and only requires VERY minor clearancing on the front drivers corner of the block. You can actually buy a Procharger kit with an F1A in it instead of the D-1SC.

The nice part about the extra cubes of the 383 is that it'll tame a bigger cam and cut the emissions. I'd look for something in the low to mid 220's intake and mid 230's exhaust duration with mid to upper 500's lift and around a 112-114 LSA. Will probably make decent N/A power and reciprocate with the boost.

Now.....as for the motor. It's going to take a LOT of boost to get to that 700. You're going to have to decide how sluggish you want the motor to be while it's N/A. Figure on anywhere from 14-18lbs of boost to make it to your goals. With that much, I'd target a 8.7-9.0 static compression ratio. But, doing that will hold it's N/A performance down quite a bit too. Food for thought there.

Lastly, don't forget about the fuel system. You're going to need a BIG fuel system to support that power.

[Tyler Wheat]

Don't overlook the transmission/rearend/suspension setup. That can make or break the car.

[lethal93ta]

I have yet to find anyone with a 93 SD car that has had any luck tuning a supercharged car at that level, I ended up spending 2000 on a accel DFI stand alone computer system, but with that you need to rewire the whole car, the computer drives some of the gauges. for 700 HP your going to need lots of fuel more than most high impedance injectors can flow, yet another reason I got the DFI it can run low impedance injectors, I put F.A.S.T. 65 lb/hr injectors in mine. sumped the fuel tank and installed a full aeromotive fuel system. I can tell you now to build a car to do what you want it to do you looking at atleast 15000, your going to need a rear and trans that can take that power. I was there 4 years and 20000 ago and I still dont have my car back on the road.

[Rumblin70SS]

To pass emissions, it's going to have to be a baby cam. But....boost loves baby cams. Keeps the cylinder pressures up especially if you go with a wide lobe sep.

If you're having the intake ported, have it ported by whom ever does the heads. It'll be matched up the best this way. Those trick flow's are LT4 designed, so either find a legit LT4 manifold, or have a LT1 welded up. Skip the edlebrock.

The heads will need to be opened up. Out of the box they're about as good as LT4 heads. Ported.......let's just use mine for an example. LE did them, they're now at 218CC runners, 64CC Chambers, and at .400 lift were moving 242CFM and crested 300 CFM @ .550 lift, on an independent bench that was extremely close tot he numbers that LE gave me. Lil' better than LT4's there.

Rockers: Comp Pro Mag, hands down.

The F1A will fit the D-1SC brackets, and only requires VERY minor clearancing on the front drivers corner of the block. You can actually buy a Procharger kit with an F1A in it instead of the D-1SC.

The nice part about the extra cubes of the 383 is that it'll tame a bigger cam and cut the emissions. I'd look for something in the low to mid 220's intake and mid 230's exhaust duration with mid to upper 500's lift and around a 112-114 LSA. Will probably make decent N/A power and reciprocate with the boost.

Now.....as for the motor. It's going to take a LOT of boost to get to that 700. You're going to have to decide how sluggish you want the motor to be while it's N/A. Figure on anywhere from 14-18lbs of boost to make it to your goals. With that much, I'd target a 8.7-9.0 static compression ratio. But, doing that will hold it's N/A performance down quite a bit too. Food for thought there.

Lastly, don't forget about the fuel system. You're going to need a BIG fuel system to support that power.

Fastbird,

That was a great post and gave me quite a bit of what I was looking for. I know about the fuel system, was planning on running around 15lbs of boost and the compression is going to be about 9 to 1. Not really worrying about it being a little sluggish, it still will be plenty powerful when its not in boost for a street car. Cam is kinda what I was thinking too and I'm glad to hear the F1A will fit with only minor clearancing and I can buy the kit instead of piecing something together.

Looks like the heads are a good choice too when some port work is done. One concern I had was the LT4 intake as I only have an LT1 at this time and was concerned on how the older style fuel lines would work on an LT4 piece.

I did call TrickFlow today and talked to Art.....he said that either manifold would fit as the heads have both sets of dowel pins? Either way, I will figure it out.

One additional question for you.....you said stay away from the Edelbrock piece.....any particular reason?

Thanks so much for your help, I appreciate it!


Don't overlook the transmission/rearend/suspension setup. That can make or break the car.

Tyler Wheat,

Thanks for the post, I do appreciate it. I just had the trans done a year ago by a local shop here in DE. It was build for about 550 hp, so I might have some upgrades to do but hopefully it will live. This wont be a race car.....a couple passes a year will be all it will make.

As for the rear, going with a 9 inch and 35 spline axles. Been through plenty of rear issues in the past so I'll make sure there are no weak points here. I don't mind spending the coin as long as I do it once.


I have yet to find anyone with a 93 SD car that has had any luck tuning a supercharged car at that level, I ended up spending 2000 on a accel DFI stand alone computer system, but with that you need to rewire the whole car, the computer drives some of the gauges. for 700 HP your going to need lots of fuel more than most high impedance injectors can flow, yet another reason I got the DFI it can run low impedance injectors, I put F.A.S.T. 65 lb/hr injectors in mine. sumped the fuel tank and installed a full aeromotive fuel system. I can tell you now to build a car to do what you want it to do you looking at atleast 15000, your going to need a rear and trans that can take that power. I was there 4 years and 20000 ago and I still dont have my car back on the road.

Lethal93ta,

Well that took some of the wind out of my sail......while I understand the SD is more trouble, someone should still be able to do it? Can I convert this car to MAF? Again I don't mind spending the money but I'm not looking to cut the car up either. The $15,000 tag was what I came up with, which is why I'm looking to do the motor then the supercharger.

Keep the comments coming guys......especially what will need to be done to tune this thing.

[Rumblin70SS]

Anyone have any other feedback?

Thanks,

Tony

[Fastbird]

I said stay away from the Edlebrock piece because it's a $460 paperweight. GM High Tech just confirmed this via testing on a stock motor w/cam and on the same motor with Edlebrock heads. Made less power iwth the stock heads, and 4 HP more with the edlebrock heads. The big problem with the Edlebrock intake is that it's only got 2/3 the plenum volume of a LT1/LT4 intake. Less air volume is going to translate into less power in this case as has been shown.

[Fixxer99TA]

Yep, better off with a stocker (or a ported stocker).

[Rumblin70SS]

Thanks again for the info guys.....last thing I need is more paperweights after having a blown motor. I can't understand why Edelbrock would build an intake that makes no more horsepower than the stocker, GMHTP just proved it..........

Thanks,

Tony

[Grr]

There is nothing wrong with the stock PCM or SD. I will never own a MAF car, i hate them with a passion. I recently switched my T/A over to 2-bar SD using the stock 94 PCM. Its very easy to do and really works great. I hope your good with CATS though, it takes quite a bit of work initially.
I would make sure you keep it at 9:1, and that F1 on 15psi should do close to 700whp
Gary

[Rumblin70SS]

Gary,

Thanks for the info, I appreciate it. I'll need to do some research here, as I'm not familar with the two bar SD and CATS. While I'm pretty handy with the carbed cars and performance, but this is a whole new world for me.

Thanks,

Tony

[1FASTSS]

I would contact some sponsors on the site and get some additional feedback with there experiences.

Nice ride BTW.

[Rumblin70SS]

We'll do and thanks for the compliment!

Thanks,

Tony