natural or boost?

[mr_frogstomper]

power wise which is better, natural build up or a boosted engine. which is safer? easier? economical? Which do you prefer?

[StudlyCamaro]

RE: natural or boost?

what type of driving is the car going to be used for, and what is the overall goal?

[mr_frogstomper]

any kind. for me its going fast but not strip use.

[Doubt_Incarnate]

forced induction has the greatest potential, like steroids. turbo is the best route for maximum power, its a "dynamic" thing. superchargers are supposed to be good ad dont have the lag issue, buy you sacrifice the ultimate potential for the instant boost. some say nos is forced induction, i dont say forced per say, its injected with fuel, so its a floater in my eye. all of the above can be cheap, or expensive depending on the power wanted. natural aspiration is the most "economical" as far as gas use, it flows X cfm, wereas forced induction flows X*Y% cfm. the added air requires more fuel. if your going to build a super cool forged this and that motor, with billet here and there, that costs alot of money. why stop at N/A? might as well build it with a cool turbo setup, since you'll have a few grand it it anyways.

unless your up to the challange of getting 300hp from N/A.

[madness_spirit]

I used to own a ford escort that I turboed. while turbo charged vehicals do have that annoying lag that a supercharged vehical doesnt, turbocharged vehicals generally have much better fuel economy than a supercharged vehical or normally aspirated vehicals. You will of course see performance gains from any type of blown vehical. running any type of forced induction is completely safe as long as you perform proper maintenance and do not really punish your car. you will lose fuel economy to superchargers, but you gain easy performance. With turbochargers you will also lose fuel economy to the old lead foot. However a turbocharger in a daily driver really does show good gains in fuel economy, while still giving you the ability to get the extra power every now and then. Plus the nicest thing about turbochargers is that if they dont make a kit for your engine, the fab work is a lot cheaper and easier.

Dont get me wrong, adding superchargers or turbochargers are expensive
the best gain I saw from my escort was about 2 mpg better so I can never get away with saying that I was doing it to offset the cost of gasoline. The cost of the turbo (expensive even though I pulled it at a salvage yard), custom headers, the plumbing for the turbo, an intercooler, then there are a couple routes you can take to oil the turbo, you can add an electric oil pump or you might be able to find or fabricate a kit to relocate your oil filter so you can tap those lines to lube your turbo

therefore easier= naturally aspired
safer = no difference really as long as you are a safe driver and perform regular maintanance
economical = the naturally aspired car you bought off the lot
power = forced induction, superchargers are the cheapest way to get high gains, however turbochargers will give you the best gains if you spend some time and money

PREFER = Forced air all the way

BTW dont get tricked by those cheap kits
turbos run off your exhaust to push more air into your engine
Superchargers are belt driven to push more air in

Electric superchargers or other bs like that will never move air faster and just creates more turbulence in the air decreasing the speed the air is able to move through

[madness_spirit]

oh btw dont forget the cost of building up your engine to handle the boost

But properly building up your engine also means better reliability and performance even without turbos or superchargers

Remember car manufacturers make engines so that they will be reliable under a range of conditions with drivers at varying levels of experiance.

[sharkey]

boost is best for power, no doubt about that. however, you need to decide what you want to do. im building an na motor with fairly mild compression. im hoping for around 200hp. the reason i dont turbo it is because the equipment needed to do it, and the fact that i dont have it. i wouldnt pay someone to build the turbo headers for me, and set it all up, that just costs to much. however, i may in the future build a supercharger setup for it. ive seen the roots style blower setup for the 660 motor, and i think with some work, i can mod it to fit with the MPFI.

[Froggx]

I vote for forced induction because I just happen to like the feel of a boosted car over NA. I mean a turbo car of course, supercharged cars feel suspiciously like their NA counterparts. The sound and bling factor don't hurt either.

edit: I just realized your sn is mr frogstomper and mine is froggx, this does not bode well for me.

[imported_germ]

common myth: you need to build your motor to add boost.

fact: they never put a turbo or S/C to the 3100/3400. the stock motor will handle boost very well WITH PROPER tuning. you have a bad tune, of course your going to blow shit up. 90% of engine failures with boost on the 3x00 is probably tuning or user error.

i would worry about the transmission before i worry about the stock motor.

[madness_spirit]

I only say to build your motor because if you are gonna take the time and expense to add boost, you might as well put the money in your motor so it will last you a little longer, run a little more efficiently, and give you a little more performance. Besides I am really not used to GM engines as I have generally been more into Fords, bad financial situations are the reason I have my grand prix but now that I have it I think I like it and want to play with it now that I have stabalized economically. BTW trust me my escort and ranger took a lot of building to handle boost effectively. You can gain a lot of power just machining your heads and intake correctly on most engines. If nothing else you are gaining throttle response and efficiency. And really what is the point of building up your engine in your daily driver if you spend more time at the gas pump then you do on the hiway.

Although I definately agree, one of the most important areas to focus on is your transaxle. Automatics suck, you lose power through them and they are made specifically to mate up to stock powerplants. The best thing to do is a manual conversion if you can find the parts or at the very least visit a dyno to tune your ECM right as soon as you finish your buildup so you can change shift points and stall speeds.

Another good idea even if you never plan on boosting is install an inline tranny cooler, normal cooling through your radiator is never enough. Its cheap and peace of mind is great. It is especially cheap when you consider the cost of rebuilding your transmission because you just keep burning out those clutch packs.

[Froggx]

I definitely agree with germ about tuning. Do it right and things will be pretty great. I'm more worried about running out of room on my MAP sensor (2-bar) than I am the structural integrity of my motor.

Also, I agree about doing a manual tranny swap. The getrag 282 or 284 tranny can take much more abuse than the automatics out there, I'd like to see one of the auto's launch a small block V8 on drag radials and not grenade. I like the gear ratios more as well in the manuals.

[Doubt_Incarnate]

just tortureing my brain... I'd love to build a turbo motor, or tubro the one i got. i don't like the idea of paying all the money for the right turbo though. I want up 15psi to the redline, though i probably would not run that all the time. i did some retard math, and it seems that a stock 3.1 with an 8.8:1cr ends with up like a 12:1cr @ 8psi. if you figure the %54 more air in the cylinder, and its still getting squished into the same combuston chamber. and you know that air is hotter than ambient, even with an intercooler. i know there is timing retard involved and the fuel enrichment helps keep things cool, but how is the tuning for that much different than for a 12:1cr N/A?

[Froggx]

I'll try to tackle that a little, but do a crappy job. As you know, timing needs to be retarded somewhat to prevent detonation. Turbo motors tend to be tuned rich. The extra fuel in the engine serves as a heat sink to absorb added heat and fight detonation. To my understanding an NA motor can't really do this so much. Mmm...that's all I have right now

[imported_germ]

you dont need to build the motor for 15psi, its just fine in its stock form as long as you can tune your car correctly.

things i would worry about at 15psi and a 3100/3400 (may not apply to some 2.8's and 3.1's)


head gaskets - stock and most replacements wont withhold 15psi. use new head bolts and resurface the heads. try to use a graphite gasket at a minimum, a copper gasket is best to handle the boost (you will get mixed results about copper gaskets, i personally like them and will use them on future builds)

aluminum heads - they flex with anything over 10psi. you NEED to use new head bolts at a minimum. ARP studs are best, but are expensive. make sure to resurface your head when you pull it off.

fuel injection - you will need some big injectors to supply the fuel you need for 10+ psi, i am currently running 42.5# injectors. and make sure you tune the car for these sized injectors, if you dont, you will end up not having a very good time.

tranny - GM tranny, need i say more?


once you get those good, THEN and ONLY then would i worry about engine internals. and then i would only worry about the pistons.

[Doubt_Incarnate]

It must be the added fuel, and maybe because the compressed volume is greater in a boosted motor, everything smashed into 50cc's vs. 25cc's. heat isnt so concentrated, i dunno. it just sems strange to me. a N/A 12:1 with CAI actually sucks cooler air in, while a turbo heats it up, you'd think it would be easy to tune the N/A. i put some stuff in DD2K and the 8psi boosted motor made way more power at every rpm than the 12:1 motor with the same guts.

so i know what will happen if my N/A motor fails...