which would be better for a street lt1. I have a4 with a 2800 stall, 383 with good rods and crank , afr 190 heads plus 373 gears and all the boltons .I run dry nos 150 now but would like to hear your opinions to which is better and drawbacks to both. Also are the cost of both comparable.

 

If that 11:1 compression in your signature is accurate, neither one of them are going to work very well for you

 

Yup!

 

I'm very happy with my blower at 7lbs on stock bottom end/stock heads, bolt ons and a relatively small 226/236 blower cam.

car made 431.6/475 on a conservative tune and runs 11.5's @ 120


I think the rockers are out of whack so my bud is going to help adjust them again. Still a bit left in the car yet.

 

I was thinking about both system ,but also I known compression would have to come down. nos as work well for me and some what safe with a dry system.

 

How what hp did you think 7lbs gave you? and is 15lbs to much for street?

 

Dude. It's not nos! NITROUS OXIDE

That is one of my biggest pet peeves.

 

Actually nitrous works well with turbos and or superchargers.No reason to get rid of the nitrous. Your compression is a touch high but you might be able to get away with low boost like 5psi and still get a decent power gain.Obviously going to lower compression would be a good thing and let you run more boost and since boost makes more power than compression less compression would be ideal. Maybe just swap put the heads for bigger chamber ones so you didn't maybe have to go into the engine. Also not sure how good your cam will work with turbo or super either. Not as up on lt1 engines as ls1 and dsms.
Buddy has sts on his lt1 but he dropped compression with different forged pistons. His car is pretty much bone stock right now except for the sts and it runs great even at 5psi.I like it.

 

Turbo will give more hp and torque than a supercharger, as long as it's mounted up front.

 

I never dyno'd the car after a good tune pre-blower but with my times I figured the car to be at 330-340 at the wheels so figure roughly 100-125rwhp added with the blower so far - again, i'm currently running a conservative tune and my rockers may be out of whack. Not sure what your definition of "too much for the street" is since this would be an opinion and each person is different.

Personally for me a mid 11 second ride is fine for the street - but this is me. My 12.5's were fine before I ran 11's and I'm betting that if I run 10.8's that too will be fine

 

To general to be of much use, and probably not true.

As you've probably guessed they both have advantages and disadvantages. Belt driven blowers consume hp. The bigger the blower the more hp. Belt driven blowers are not as suitable for sustained high rpm use. The belt drive being the biggest problem. They do produce good torque at lower levels. Power production is instantaneous and heat is not normally a problem.
Turbo's don't consume hp and are great for high rpm's. But they normally have some turbo lag, heat can be a problem, and installation is normally more difficult than a blower.
I'm sure there are some others things I haven't thought of. Anyone?

 

what are the cost of a basic turbo sys. You said mounted up front, is this the same as supercharger. thanks

 

What, exactly, was not true about my statement "A turbo will give more hp and torque than a supercharger"?

I did a direct comparison. Switched from a Vortech T-trim to a Homemade T-76 turbo. Same intercooler, same [blower] cam, even a supposedly crappy log-style manifold (supercharger had the advantage of Hooker LT's). The turbo made 30 hp more than the supercharger at the same boost level. It also made 60+ more ft-lb torque and did it all 1000 rpm sooner.

 

at the same boost a turbo will make more power in the end, but in most cases makes it later in the power band. a turbo needs time to spool up to it's boost level where as a supercharger is always boosting as long as the engine is running.

i bet if you take a look at your dyno sheet, the power from the supercharger is a flater curve than the turbo charger.

 

Both comsume some hp, there's no such thing as a free lunch. There are several ways to reduce or eliminate belt slip these days, from shot peening the pulleys to a cog system. Superchargers are used in everything from drag cars to endurance road racers, why is high RPM a problem? Usually a turbo will produce better low end torque than a blower, unless you're talking about positive displacement superchargers. Power production with a supercharger is not instantaneous, you have to get the blower up to speed the same as a turbo (again, not talking about positive displacement blowers). Heat is a problem any time you compress air.

Clarify, with a turbo, high underhood heat can be a problem if the turbo system is not efficient. Lag is only a problem in mismatched applications like a T88 on a Supra.

I agree with Mike that a turbo will generally make more power than a supercharger, but they don't always have to be mounted up front.

Explanation... A front mount system generally mounts the turbo in the engine bay somewhere. The new craze at the moment is known as remote mount turbo systems (STS) which mounts the turbo farther back in the exhaust system for ease of installation.