ANTI VENOM

My build originally started out as a Turbo build. It started with the engine. 383 LT1. 9 to 1 compression. I'm kinda feeling like giving up on the turbo and just put in a supercharger kit. It seems like the easiest and fastest way. My ultimate goal would be somewhere around 600 rwhp. What are your thoughts? Anyone experienced with both? Pro's and cons? Basically, is the turbo worth the extra hassle? I do all my own work, that's why I ask.

P.S. I really just want a car that I can beat the crap out of. It will be a street car, but it will see some time at racing events as well. Drag, autox, road race, etc.

illenema

Im sure you know that 600 RWHP is completely obtainable with a bolt on SC. Correct?

ANTI VENOM

Yeah, that's what makes it so tempting. At first I thought it would be kinda fun to build my own turbo system. Now that things in my life have changed since starting the engine build, I don't seem to have the ambition and time and I want to drive my car. I'm going to put the engine in N/A and run it, but I still want FI.

BrianCunningham

That's the route I took

I drove it to the autocross yesterday

The things a blast

ANTI VENOM

How do you guys manage fuel and spark retard?

BrianCunningham

My tuner used the stock computer

I'm also running water injection

illenema

I use an Msd BTM with adjustable retard. I adjust to the quality of the fuel Race gas no retard pump minus. Stock Motor though. So Far so good...

ANTI VENOM

Can anyone tell me about driveability between the two? Turbo's can obviously come on pretty strong. Would it be controllable around a long sweeping corner? How about the blower? If boost is a product of RPM then it must be more predictable.

qwiketz

supercharger will be easier to install versus fabbing up a turbo kit. 600rwhp is going to require an upgraded bracket and the new Ti trim vortech blower or ysi to get there. Our engines aren't very efficient from what I've seen. A maxed out t trim will barely hit 600 rwhp due to the belt slip caused by using a 7.35" crank pulley. The small crank requires tiny blower pullies to spin the thing hard enough to make boost.

Anything above 600 rwhp and turbo is easier. I have a ysi on mine but I'm not convinced it'll make a ton of power without a bunch of rpm.

Blower boost is linear so it's not too hard to tune for unless you're getting slip. You're probably going to want a 2 bar tune either way as you're going to be needing about 14-16 psi with a blower and maybe about 10-12 with a turbo.

ANTI VENOM

I'm using a Megasquirt for control. So many possiblilies with it. For a DIY guy they are very cool. As far as blower trims, I know nothing. TI or YSI means nothing to me. LOL I'm concerned that if I get to my power goal with a turbo, the car will act like a 2 stroke and come on so hard that if it's not pointed straight, well, bad things will happen. Unfortunately I don't have any friends with fast cars anymore. I don't even know anyone with a modified vette except my buddy who bought my old 92. That's why I'm asking for your opinions.

Street Lethal

Turbo's are easier because you essentially do the opposite to control boost as opposed to a supercharger. With turbo's, your starting with a blower that can give you over 30-psi no problem because of exhaust pressure/flow, and you bring boost down to a more comfortable level via a wastegate, so boost will inevitably follow through throughout the RPM band, on tap. With superchargers the way they are, we're limited to pulley size, and what you get is what you get at a particular RPM. However, starting off with a supercharger that will inevitably follow through like a turbo and give you over 30-psi no problem, in this case, like an F2 Procharger, while controlling boost with a wastegate on the cold side, which is more than doable, then suddenly the supercharger becomes more efficient than a turbo of similar cfm. Meaning; no lag, no excessive EGT's, less weight, and unlimited boost pressure throughout the RPM band because F2's will make way over 1000-HP no problem...

mn_vette

There are other tricks to controlling boost with superchargers as well. They are not the most efficient methods, but work very well.

One thing is the put a restriction plate on the intake to the supercharger. This limits the CFM and therefor the boost on the output. Some of the C5 guys use this method and they like it.

The other thing I've seen people do is put a wastegate on the intake piping. Once the pressure gets too high then it bleeds off some to keep it in the safe range.

Both methods require you to pulley the supercharger for more than what you need, but they also allow full boost to come on at a much lower RPM range.

silver86

I used an inlet restrictor on my FI '86 to limit it to 12 psi. The real benefit I was searching for was being able to run a smaller pulley so that the boost came on quicker. I only ended up pushing 390-400 rwhp on that setup, though.

Street Lethal

That is the route I was going to go with mine, currently running a '95 Corvette with D1SC, and was going to tig weld in a 44mm wastegate flange on the intake tubing, pulley it up and set boost for no more than 20-psi. Decided to wait for an F1 head unit first. Still want to route the charge dump from the wastegate to the exhaust to keep things quiet at idle, and the bypassed charge from the wastegate should be able to overcome any slight exhaust resistance...

mn_vette

I'm sure you already thought of this, but I'll throw it out there anyway for people reading, make sure you do this BEFORE the MAF sensor, if there is one, and before the intercooler.

There's no reason to cool off the air if it is going to be dumped and you don't want the MAF reading to be messed up. Not a good idea for people that have the MAF on the inlet to the supercharger.

ANTI VENOM

A lot of good arguments FOR the superchargers. I'm learning.

silver86

I did study that route as well when building my setup. I didn't go the wastegate route as the blower would be less efficient; meaning it's doing the work and generating the parasitic loss to build 12 psi, and you only get 10 psi after the wastegate (just made those up as an example).

BrianCunningham

My MAF is before the blower, but the BOV has a tube to dump back in after the MAF but ahead of the blower inlet

mn_vette

That works for a BOV when you are not building any boost, but if you are doing it to bleed off boost you are heating the air from the compression and then dumping it back into the inlet of the supercharger to be heated again.