Guys, I posted this in tech section but figured it would also be helpful to post it here since my future may well involve a blower

So I've currently got a built LS-6 in my car. Puts out nearly 500hp, but a little soft at low RPMs.

There was some valvetrain noise, so I took it to Icon Autosports in Stafford (near Houston).

Apparently a cam lobe is wiped or about to wipe or something or other and the cam needs to be changed.

Now, I know that costs $$$. I eventually wanted to upgrade the engine in any event, so no is probably the time to do it.

Here is what I want: great low-end torque for instant throttle response, good HP up top, and the possiblity to upgrade the HP up top even more if desired down the road.

So I figure there are a couple of options.

One is to go with a Kenn Belle. I know those things make MASSIVE torque all over the RPM range. But I'm not sure I like the new hood you have to get, they are costly, and I'm not even sure anyone around Houston can install them. Plus I understand they put out so much torque they break things rather easily

Another is to have an LS-3 or something built. Stroke/bore it out as much as is reasonably possible, get some good heads on there, and put in a cam that is big enough to get some pretty good up top HP but that does not give up anything on the low end so to keep instant power when I touch the gas. Then, if more power is needed down the road, hook up a centrigul (however its spelled) blower to increase power up top even further, but keeping down low torque under control so hopefully tranny/rear end, etc. don't start breaking.

There is always an LS-7 option but I think those cost lots more money.

Any thoughts on the matter? And any suggestions as to possible starting points for a budget build with great potential?

Thanks!

 

I'm fairly certain you know this, but you'll never build a n/a motor,that will give you that huge, instant torque of a Kenne-Bell blower.

I don't know your budget or the limit of power/torque you are seeking - but have you considered replacing the cam and doing an A&A centrifugal? You'd be very surprised at how fast these centrifugals get up on the torque curve.

 

I agree that a SC is your best bet. If you want more HP than you currently have you will need to address your drivetrain. It's a slippery slope.

 

C Williams, I understand a n/a motor will never get me the massive low-end torque and Kenne-Bell will. But I figure I can get enough torque without a Kenne-Bell - seems a Kenne-Bell is overkill in the sense that so much low-end torque will just spin the tires or break stuff.

Yea, I've considered changing the cam and just bolting on a centrifugal, I just worry that wouldn't get me the low-end torque I'm looking for.

 

The centrifugal will give you enough torque down low that traction becomes an issue. Especially if you change your cam to a blower cam at the same time.

Is your car an auto or stick?

 

As the post above stated - you will get sufficient enough low end torque that you'll need some very sticky tires.

Additionally, if you put a forged rotating assembly in that LS6 you can turn the boost up to make it "stupid fast"..

 

Thanks guys. My car is a stick.

I understand a centrifigal can spool up quick, but I really want that "off idle" feel that I do not believe centrifigal's are associated with.

Any ideas whether a TVS 2300 will bolt up to a LS-6 5.7 liter?

 

[QUOTE=Jack Daniels;1577430775]Thanks guys. My car is a stick.

I understand a centrifigal can spool up quick, but I really want that "off idle" feel that I do not believe centrifigal's are associated with.

Any ideas whether a TVS 2300 will bolt up to a LS-6 5.7 liter?[/QUOTE


There is not going to be lag. not as your thinking anyway. Though the centri blower looks like a turbo its still a blower. its going to make power as soon as you smash the throttle.

run your 347 or maybe 383 forged rods and pistons and crank if you got the money with 9.5 :1 static compression ratio with some good heads and good valve train and fuel system and the car will be retarted fast. Guranteed.

 

Yes and no on that...

The blower definitely will fit but you need some fab work...not much, but some. You also will need a hood change.

You could also make place the Edlebrock E-Force on the C5 but loke the Maggie 2300, you'll need a hood change (the E-Force almost clears a stocker, so probably a 3/4" high rise like the RK Sport)

 

Seriously, who starts a race "off idle"? I see this posted all the time.

Any experienced person that roll races starts from at least 4k rpm on the hit and if you drag race, even higher if you want a good 60ft.

Just put a nice S/C cam in it. A&A V3 Si trim kit with 3.6 pulley and new aftermarket crank pulley(don't reuse old stock one) and use a proven tuner and you will be grinning from ear to ear.

 

Its hard to describe how much fun a high 600 low 700 WHP car is. It makes you Smile everytime.

 

I'm not worried about racing it so much guys, I just don't want it to be weak down low.

I am now thinking about turning my 346 into a 383, forging it, and going with a centrifagul as you guys suggest.

Do the cams you guys put in the centrifagul cars to make upstairs HP mean a weak low-end? A weak low end is what I am trying to avoid.

Thanks!

 

Heres the deal. Typically when everything else is equal or very similar the larger displacement engine will make more power. (I'm going to catch fire for this LOL) in other words if you have a stock displacement engine with a static compression ratio of 9.5 : 1, with a set of AFR 225 heads and a T-trim V-3 and say A&A stage III blower cam running 12 LBS of boost and methenol, the car should make in the upper 600 to 700 plus WHP and high 500's low 600's in the TQ department too. You will make this kind of power easily with a good conservative tune and the right fuel system Ect. At that kind of power level, there will be no street tire that is not some sort of R compound tire that will hook up. I gurantee it. If you run a typical street tire I dont care how wide I gurantee you will destroy the tires at an idle, at 80, 90 even 100 miles an hour. how's that suit you for low end TQ. I'll put it to you like this your traction control or TQ control will be your right foot. You will learn to feather the throttle.

On the other end of the spectrum if You take that same engine same static compression ratio same heads, same fuel system, same cam the bigger one is definately going to show a substatntial gain in lowend Torque simply because the engine is Larger. at the same time, if you run the Exact pully you ran on the 347 on the 383 you will see less boost and the engine will make more power.

HTH

 

I understand all that MVP. My question is not about high end HP - I understand there will be a ****-ton of it if I go with a centrifagul.

My one worry is that the car would not be as "fun" to use as a daily driver because, while there is tons of power, you got to let the car rev, if only for a bit, to get to it.

A 383 naturally will give one more low-end torque, so my question is how the cams are set up for these high-HP centrifugal cars - are they cammed to give huge high end, but leave the low-end soft? That would worry me. I'm sure a 383 cammed for reasonable low-end would be fine, but I'm not so sure about a 383 cammed for uber-high end at the expense of low end.

Thanks again!

 

That's a fair question. The answer is this. When supercharging, you do not need as much cam as you need in a N/A setup to make compairable power as the supercharger is going to take care of what is not there (TO A POINT) what I'm trying to say is that your not going to get a car that makes 700 Peak WHP but only 400 peak WTQ. with a typical blower spec Cam. You could throw a Huge cam in the car, one that most would use for N/A application and im sure the car is going to make huge HP numbers but its not going to be very friendly on the street and you will probably loose some lowend TQ however, with that said the blower will take care of a lot of that.

alot of the manufacturers out there who built "blower spec" cams for these cars designe the cams relatively mild because they know that you dont need a monster cam to make big HP and TQ. A lot of the "blower spec" cams will have a larger (in crankshaft degrees) Lobe Speration angle and smaller (in crank shaft degrees) duration and these cams will typicall sound mild and not have as much of a lopy idle as the N/A cams do mostly due to the different Lobe Seperation Angle. Of course, there is always a traid off when it comes to Hight end HP and Low end TQ. However, these cam manufacturers try to optomize both so you can get one killer street car. We could sit here and talk all day about this but the bottom line is there are plenty of "blower spec" cams out there that will yeild you the results your looking for.

Example Given my Car with a forged 383 (stock LS6 heads with the exception of the valve springs), a static compression Ratio of 9.0 :1 and a Vortec T-Trim V-3 blower, and methenol injection was making about 10-12 LBS of boost made 684 WHP and just 612 WTQ

The car was making over 400 WTQ at about 2,700 RPM's (thats dam near as soon as you get into the throttle) by the time the car hit 5,000 RPM (which was in the blink of an eye almost) the TQ output had almost doubled and neared it's peak at just about 600 the car drove almost like stock until you cracked on it.

If you do an A&A blower kit with one of thier "blower cams" with a forged 383, the proper fuel system, a good set of heads and the transmission and rear end to compliment it, I almost gurantee that the car will make you happy in every department. you will be able to cruise around and no one will know what you have a car that will smoke most crotch rockets until it's too late. Ontop of all that when your not boosting and just highway driving the car will get just as good if not better gas mileage then stock.

 

You are worried about the opposite of what will happen. You will have so much torque you will not be able to hook and when you do you will break stock components. You will need big and sticky tires as well as a hardened drivetrain. You will not be able to go WOT without smoking even drag radials. As above you will have to feather your throttle for traction.

 

YES! and its so much fun.

 

Haha, thanks guys. I'm on board now.

MVP, you mentioned the AA setup. I think the shop my car is at now uses a D1SC Procharger. I take it that is a comperable supercharger and OK to use?

Thanks again!

 

Oh yeah bro you will be fine

The Vortech T-Trim V3 Specs are as follows

Performance Specs
Max Speed:
55000 RPM
Max Boost:
26 PSI
Max Flow:
1200 CFM
Max Power:
825 HP
Peak Efficiency:
73%
Performance specs apply to units equipped with standard gearcase.

Dimensions
Discharge OD:
2.75"
Inlet OD:
3.5"
Discharge ID:
2.38"
Inducer Diameter:
3.1"



The Vortech V-7 YSi (the big boy for the vortech units) specs are

"Large blower" performance in a smaller package that fits most existing Vortech bracketry


•Available with straight or curved discharge in clockwise rotation only
•Part numbers below do not include drive pulley
•9.162" Wide, 10.490" Tall, 6.126" Deep (not including input shaft)

Performance Specs
Max Speed:
65000 RPM
Max Boost:
30 PSI
Max Flow:
1600 CFM
Max Power:
1200 HP
Peak Efficiency:
78%
Performance specs apply to units equipped with heavy duty gearcase.

Dimensions
Discharge OD:
3"
Inlet OD:
4"
Discharge ID:
2.64"
Inducer Diameter:
3.7"



[B]The procharger D1SC Head Unit specs are in the following linkB]


http://www.procharger.com/models.shtml


Anyone of these is going to make you smile all the time.

not sure how much power you want but you may actually be happier stepping down to a P1SC1 if your going with a procharger head unit

Of course if your building a 383 theres always the option to go to an iron block and take advantage of that 4 inch stroke crank that you would be utilizing with a 383 stroker anyway and go to a 403/408 simply by using a larger piston. in the end bro theres tons of options either way the car is going to crush almost anything you line up against as long as you have a tune and a driveline to support it.

 

The beauty of Centri setups is that you can pretty much cam them anyway you want and then throw the boost on it. ie- Low-end cam, high-end cam, -overlap, +overlap, and it will still haul the mail.

But, it sounds to me what you need is to cam it, 383 it, A&A V3 Si trim it, 10% OD crank pulley it, 3.4" S/C pulley it, and Restrictor plate the heck out of it. Will have sick rwtq down low, and be able to open it up later on.