Cubes or Boost

[1978TA]

Hey everyone

Just curious on what everyones opinion was on cubic inches vs. small cube boosted applications. Im curious because I currently have a 455 storked to 474 Pontiac engine sitting in my garage waiting to be put into my 78 Trans Am. I bought it a year ago thinking its was what I wanted for my car, but over the year and lots of reading I have been toying with the idea of going to a smaller cube with a single turbo set up based off an LSx style engine. I spend a lot of time on "performancetrucks.net" as I have a 03 sierra, and there are guys making some awsome numbers boosting the GM truck engines. There are some guys making 500whp on the small 4.8 and thats with only a cam change and the rest is stock, this is what has got me thinking about a possible change. These engines are still absolutely drivable and not to mention efficient. My 474 is about 600/600 crank hp +/- a few and a very broad torque curve and i realize this is the benefit of cubic inches, but it just seems that making around the same numbers (probably sacrificing some torque) with only a 4.8 and some boost and having the ability to get 20+ mpg seems like the better choice for the long run...I dunno maybe im crazy haha because I do have a perfectly good and powerful engine sitting in my garage....

Let me know what you guys think...Is it worth all the swap work and turbo fab-up to reap the benefits of boost and small cube efficiency, or just stick with big guns in the garage

Thanks
Mike

[gsxrken]

Boosting brings more air and fuel to the party only when you want it. And it can be a somewhat lighter weight way to make power if pro-touring and not outright muscle car beast is planned.

But you ask if its worth it... I'd say done and on the shelf is hard to compete with. It's probably not your last project- boost the next one. Or this one in a subsequent iteration. These cars often live multiple lives if you keep them long enough.

[SLO_Z28]

Boost is the way to go if its in the budget.


Hey everyone

There are some guys making 500whp on the small 4.8 and thats with only a cam change and the rest is stock, this is what has got me thinking about a possible change. These engines are still absolutely drivable and not to mention efficient.

VERY interested in this, im doing a 4.8 build for a friend right now. Found a 4.8 and 4L60 with harness/computer for $750. Any links to that build? Ill hunt through that site later tonight.

[SS PUNISHER]

Cubes+boost

[1978TA]

Boosting brings more air and fuel to the party only when you want it. And it can be a somewhat lighter weight way to make power if pro-touring and not outright muscle car beast is planned.

But you ask if its worth it... I'd say done and on the shelf is hard to compete with. It's probably not your last project- boost the next one. Or this one in a subsequent iteration. These cars often live multiple lives if you keep them long enough.

Yah thats why the boost seems somewhat appealing because going with a 4.8, will make low speed in city and low rpm highways cruises awesome for fuel efficiency wise, then if wanted mash the pedal and hold on.

Yah, the on the shelf aspect is tough, becuase everytime I go out into the garage I see that nice big pontiac sitting there, just waiting to be run hard. No your right definitly wont be my last project, unless the wife gets her say lol

[1978TA]

Boost is the way to go if its in the budget.



VERY interested in this, im doing a 4.8 build for a friend right now. Found a 4.8 and 4L60 with harness/computer for $750. Any links to that build? Ill hunt through that site later tonight.


Yah its definetly interesting because the 4.8 was always written off, especially in the truck world where torque counts for a lot. But guys are now making awsome power with them with a single turbo set up and the stock bottom ends are taking it, I guess the short stroke is whats making the difference.

Here's the thread I just read over there the other day
http://www.performancetrucks.net/forums/forced-induction-159/another-4-8-making-500-600-hp-497204/

I beleive there is a guy running 10's with a turbo 4.8 with stock bottom end and some nitrous... in a truck!!!

[1978TA]

Cubes+boost

Has seriously crossed my mind...wouldnt take much boost to make serious power

[Scott Parkhurst]

We just went through this on the new project. After weighing all the options, we're going with cubes.

Less weight.

Less heat.

Less tuning.

Less maintenance.

Same cost/same power. The money in the supercharger fund is going toward a stroker bottom end.

A turbo 4.8 is cute and all, but a 500ci LS will be better.

[SS PUNISHER]

[/QUOTE] A turbo 4.8 is cute and all, but a 500ci LS will be better.[/QUOTE]


Have you not seen the 1200 horse stock bottom 4.8 article?????

[Nothingface5384]

i say boosted 474 poncho...if compression is too high like 10-11;1 you can just run it on e-85

[SLO_Z28]

You could procharge that 474 and make 900HP on pump gas. Its been done before.

[1978TA]

Hey everyone

Thanks for all the replys

SSPunisher...That 1200hp 4.8 article is what got me thinking.

I think Ive decided to stay with my 474 poncho, and for the reasons said above, heat, tuning, less weight. And weight is one thing im trying to shed, these 70's f-body's are surprisingly heavy. Also I think the power on demand aspect of the big cubes will help alot in my heavy car. I have a 4.8 in my 03 Sierra so I guess I will have to save up and turbo it..

SLO Z28....procharger, 800hp, pumpgas.....sounds like fun

[Procharmo]

Your 477CI and a ProCharger F1X will be more than enough for any Protouring 2nd Gen F Body.

Check out this 540 F2 Protouring Camaro. M6fljL4lMFs&list=UULHj7EJwYMIXC86MyjaLVQg&index=9&feature=plpp_video

[RSX302]

I love the testostrone and the grunt of a big block. The sound and power is awesome and will never die.

...but...

I'm loving the boosted cubically challenged motors. Off power, you have a very docile driver with way better gas millage.

LQ9 370ci Twin Turbo (GT28's at 10psi)
https://static1.pt-content.com/images/pt/2012/05/Dyno2-1.jpg

[WS6]

I say it depends on where you make want to make the power. I haven't checked out the links you posted but I get a little leery of results that only tout peak numbers ie 600hp 4.8. When comparing cubes versus boost or even more cubes I want to know where the power will come in as that tells me how the car will drive. A lot of high horsepower turbo, especially single turbo, builds do not make power down low. To me that is boring and I'll take the grunt of a big cube motor any day. Ron's car has me drooling because he makes great low end power that pulls everywhere with no lag. It's not like your common boosted application that feels like a switch when you finally hit boost.

Keep this in mind when deciding what engine or how to build the engine for a project. Don't get caught up in the numbers so much as where you make the power because where you make the power will determine how much you enjoy driving the car. Put the wrong combination together with your driving style and you'll be disappointed in the results even if the power numbers are impressive. Good luck

[opnwide]

I run low boost 10-11psi on my 8:1 455 solid roller street TA. I love frying the 335 Kumhos at 60mph! Have your cake and eat it too! Torque is king for a street car. On a dynojet, I made 500+rwhp and 600tq with only 7lbs at pig rich! I havent been back since making carb changes, which reminds me...

Carb tuning can be a pain. but there are companies now that are fuel injecting our ponchos. But then you've got to learn to program FI:(

There are a bunch of us over at Pontiac Zone. Don't go there if you're serious about the 4.8 idea, cuz these guys will change your mind.

[zombiekiller]

Think this is a hard decision? When I was deciding on my new pickup truck last year, I was torn between a v8, diesel and a twin turbo V6?! .

I ended up with an ecoboost f-150. I don't care what anyone says, it hauls, I love it and I get 21-22mpg on the highway out of a full size crew cab pickup. Not to mention the 385 hourse/414 ft lbs.

I love it so much that i would have put the same motor in my galaxie if they werent still going for 10 grand out of the junkyard.

It re-ignited my love for turbo vehicles. Instead of going 428, 460 or even 351 in my galaxie, I'm opting to run a 306 smallblock and single or twins turbos. Right now its looking like a single because I'm running out of money . :)

I've got no doubt that I'll end up with more power than an NA 460, with half the weight, none of the shoehorning problems and better weight distribution.

I'll be down on torque compared to the brute 460s, but seriously, I'm going from a VERY tired 289 that dynoed at 88 horsepower before I pulled it. I'd be kidding myself if 550HP and 400-450 ft lbs wouldn't be a serious kick in the pants.