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Old 09-22-2008, 07:43 AM   #1
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Bad Question: How much is enough

Ok, before we even go there, I know, you can never have enough HP.

However, the role this truck will have is that of a street-able, occasional weekend drag run.

So, with that said, a little back ground info:

I am re-building, (for the second time) a truck my Dad bought new in 1970. A GM C1500 Custom (link in sig).

I found a SWEET deal on a 383. Forged crank, forged H-beam rods and a forged pistons, all the machine work done on an 89 roller, 4 bolt main truck block. I have a set of GMPP Fast Burn aluminum heads and a Vortec Air Gap intake I bought here on the board. Here's the problem: Compression ratio of this motor is 8.5:1 is perfect for forced induction and I started researching that path... which leads me to the question, how much is enough HP for a street/strip truck, that will never see a load in it's bed and be driven mostly on the street?

Right now, without the "hair dryers" I can be over 500hp with a new set of .30 over forged pistons, the right cam and a small nitrous plate. Not sure what it would be with the pistons I have.

With turbos, I can be easily at 900hp and pretty close to the max my block will support. (I can do a half fill to get me there).

Trans is a well built (1200hp) 700R4 and I am building a 9" rear with 4.11 or 4.56's. Stall needs to be street-able, so around 2900-3600 to match the cam that will go in this. I still need to buy the cam, which is dependent on the way I go... most say put a nitrous cam in, which will handle the turbos, but it's the pistons that's the issue. I want to do this once.
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Old 09-22-2008, 08:41 AM   #2
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Re: Bad Question: How much is enough

I have a Procharger on the 383 in my boat 9.5 comp and 7 psi boost dyno at 540 HP very economical as long as you keep the foot out of it. Has amazing mid range acceleration. Procharger owns most of the speed records according to their website. www.procharger.com
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Old 09-22-2008, 09:38 AM   #3
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Re: Bad Question: How much is enough

Well, that depends. with nitrous, it's an instant hp shot at one time: a big boost of pressure. with a supercharger, you have hp all the time. with turbos, until you reach the correct exhaust pressure, they won't kick in.

i wouldn't use nitrous. seen too many problems with them. mostly because they weren't used correctly, but still. . .

what i would do though is build it for the best n/a hp, then add either the turbos or supercharger.

just remember though, the more hp you go with, the more fuel you have to add, meaning the less mpg you get.
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Last edited by nightmare; 09-22-2008 at 09:39 AM.
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Old 09-22-2008, 09:39 AM   #4
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Re: Bad Question: How much is enough

The amount of HP you have is only as usefull as what you can put down. So I'd be planning on some race slicks to help you launch. May even consider tubbing.

For the street a 500HP N/A engine sounds nice, but it's streetability will be deminshed by the cam that you'll have to run to get there.

I'd scale it back to a 400-450 HP N/A engine, and then run some force induction to get you the extra HP.
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Old 09-22-2008, 09:43 AM   #5
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Re: Bad Question: How much is enough

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Originally Posted by nightmare View Post
Well, that depends. with nitrous, it's an instant hp shot at one time: a big boost of pressure. with a supercharger, you have hp all the time. with turbos, until you reach the correct exhaust pressure, they won't kick in.

i wouldn't use nitrous. seen too many problems with them. mostly because they weren't used correctly, but still. . .

what i would do though is build it for the best n/a hp, then add either the turbos or supercharger.

just remember though, the more hp you go with, the more fuel you have to add, meaning the less mpg you get.
These are two separate animals. This is the problem I face. To get the most out of a turbo (Supercharger is not on the plate) or a charger, you have to run low compression and a cam with far more LSA. To get more HP out of a N/A motor, it's less LSA and more compression.

Fuel? Who cares about MPG, this is fun only. I have a 4wd truck that will get better fuel economy and haul schtuff.

Quote:
Originally Posted by Ackattack View Post
The amount of HP you have is only as usefull as what you can put down. So I'd be planning on some race slicks to help you launch. May even consider tubbing.

For the street a 500HP N/A engine sounds nice, but it's streetability will be deminshed by the cam that you'll have to run to get there.

I'd scale it back to a 400-450 HP N/A engine, and then run some force induction to get you the extra HP.

See my answer above. Different build types.

I have 31" M/T race slicks for it. The Furd 9" has 40 spline gun drilled axleshafts, a truss and I may go four link. If I stay leaf spring, it's getting traction bars.

Last edited by FormerMember; 09-22-2008 at 09:50 AM.
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Old 09-22-2008, 10:29 PM   #6
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Re: Bad Question: How much is enough

I`d go for 450-500 hp.You can do more impressive power,but I doubt it would be very streetable.Unless,you did run a supercharger.And that`s what I`d do with that motor.That`s what it was built for.You could change the compression or start with a different motor.That`s my opinion.
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Old 09-22-2008, 10:40 PM   #7
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Re: Bad Question: How much is enough

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Originally Posted by special-K View Post
I`d go for 450-500 hp.You can do more impressive power,but I doubt it would be very streetable.Unless,you did run a supercharger.And that`s what I`d do with that motor.That`s what it was built for.You could change the compression or start with a different motor.That`s my opinion.
Turbo is what it was built for.
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Old 09-22-2008, 10:52 PM   #8
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Re: Bad Question: How much is enough

Is this just a weekend toy? I'm currently building a motor for my truck that might as well be a race motor. Its a 422c.i. small block with forged crank, Manley h-beam rods, JE pistons, Dart Pro 1 Aluminum heads, Dart single plane intake, custom ground hydraulic roller, Comp Cams hydraulic roller lifters, Comp Cams roller rockers, 850 Quickfuel carb, MSD Pro Billet Distributor, and MSD 6AL box. It will have a 10.5 to 1 compression ratio and should make between 600 to 650 at the crank. Im building that motor to drag race and have some fun on the street. i think a turboed motor would be cool though.
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Old 09-22-2008, 11:19 PM   #9
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Re: Bad Question: How much is enough

Forced induction is going to yield the most streetable horsepower period. If you look around you can buy a turbo and all the accessories for about the same price as the pistons you are going to have to buy. From your other builds, I know you can fabricate the plumbing and exhaust. Going turbo would be an absolute no-brainer IMO.
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Old 09-23-2008, 12:24 AM   #10
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Re: Bad Question: How much is enough

Quote:
Originally Posted by 67_C-30 View Post
Forced induction is going to yield the most streetable horsepower period. If you look around you can buy a turbo and all the accessories for about the same price as the pistons you are going to have to buy. From your other builds, I know you can fabricate the plumbing and exhaust. Going turbo would be an absolute no-brainer IMO.


What immediately came to mind when I saw this was my buddy's '69 Camaro and my other buddy's old '92 Toyota MR2. The Camaro has a built 350 with a pretty big cam, four speed, all the good stuff. The MR2 was a factory turbo car, he'd messed with it a little from stock, but not much at all. I hate to admit it, but as they sat the MR2 would've taken the Camaro in a race hands down no matter what. As far as streetability goes, the MR2 was again much better at that than the Camaro.

I know in some ways that's comparing apples to oranges but you get the picture. If I was in your shoes I'd go the turbo route for sure. Seemingly, the most difficult part would be maintaining self-control with how much boost you run .
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Old 09-23-2008, 06:00 AM   #11
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Re: Bad Question: How much is enough

The turbo would be the most streetable. Heck you can start them with a stock starter and they are basically a 300 hp motor till you build boost. The driveability would be awesome. Don't get me wrong I love the sound of a thumping cam in a hot rod and I don't mean one of the wussy ones you hear in most of the street rods at the local car shows, I mean one that hits a lick. But, they aren't the most streetable. I'm going the n/a route with my new motor with a big hydraulic roller, but given the choice I'd go turbo.
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Old 09-23-2008, 06:05 AM   #12
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Re: Bad Question: How much is enough

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Originally Posted by grendel View Post
Turbo is what it was built for.
You get my drift.Forced induction vs natural.
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