I thought I saw a post or thread on this once, but I can't seem to find it.

Essentially, I was looking for a rough guide on how much to expect to pay for specific mods and how much HP gains to get an idea of dollar to HP ratio for an LS3 engine.

I.E.

Tune: ~$500 / 15 HP
Headers ~ $1000-$1900 25 HP
Exhaust ~$500-$1500 - 10 HP
Supercharger ~$6K-$10k - 150-200 HP
Cam ~$1500-$2500 - 30-50 HP

etc...

P.S. I realize prices will vary and HP are just estimates...still I think a guide would be useful to realize a rough $ ---> HP ratio


Is there anything like that around?

 

Don't know an answer to your question but I think it's a good one. Im going to keep an eye on your thread. Hopefully you get some good replies.

 

Dollar to dollar, supercharger will be the most effect method.
As for where you want the power, this will dictate the type of super charger.

If you want hard hit of mid range to top end, then centrifugal blower.

If you want hard hit of idle to top end then, then roots blower instead,

A for total HP, call 650hp very usable full time on a stock LS 3 with either a TVS2300 or TVS2675 for road coarse use.

If for drag strip use, then 750HP is not out the question with a centrifugal force supercharger, since you will be in the power for less than 14 seconds each time instead.

The easy to to sum it up, is think atmosphere pressure.
So lets take sea lever where the pressure is 14.7psi.
So 14.7 psi, times the compression of the engine, lets use 11 to 1, and you can end up with close to 161.7 psi in the cylinders.

Now here is where the cam comes in, since we art trying to get the motor to suck in as much air volume that is can, and the better the cam, the more air volume the motor sucks to get up to that 161.7 PSI cylinder pressure at combustion.

Now if we take a blower, we are not longer limited by that 14.7 static air pressure, since we are compressing the air into the motor isntead.

So we start with the 14.7 air pressure, add in say 10 lbs of boost via the blower, and now that 14.7 static air pressure number became 28.7 instead. So now we could have up to 315.7 psi in the cylinders at combustion instead.

Also, since the motor is not longer having to suck the air in, but instead begin forced feed air instead, head and intake runner porting plays way less than a difference isntead.

So yes, it possible to mod a LS3 to make 600hp in N/A, but with a supercharger on the stock block with just long tube headers instead, your starting point is 650 hp instead.

And one last thing, the farther up you are in altitude, the less that static air pressure is. In Denver, the static air pressure is 11.7 psi, so when adding a blower, you can adjust for the lower air static level pressure to get you back to sea level type power with added boost.

With a naturally aspirated engine, your stuck with that 11.7 psi pressure (up to 128.7 psi at combustion on a 11 to 1 motor), and have to try to make the difference up on the other side with motor compression to increase combustion PSI instead.

As for break down of the items you listed,
Long tube header will yield about 25hp increase since they scavenge more exhaust from the cylinders,
Tune on on a stock motor will yield you about 16hp.
Exhaust system at the most, about 10HP if you have a stock system, and going to a straight through system with long high flow cats.
So the above all added up in cost, your going to gain at total of about 45HP.

 

Not sure if this helps, but I just recently had American Racing headers, high flow cats, axle back, intake, and tune installed on my 08 M6 base model and gained 35whp and pick up 30wtq.

Headers with high flow cats - $1900

Billy Boat Bullets axle back - $900

Vararam Intake - $475

Tune - $500

$3775 = 35whp and 30wtq

Just my two cents, hope this helps a little.

 

Good stuff guys, keep it coming. The supercharger I kind of had an idea on already, I used to have an eForce roots blower.

The N/A mods are those which I'm not familiar with though. Heads/Cam/Ported whatevers..flex fuel system etc

 

Cam is pretty decent HP/$. Mileage will vary though. Mild cams are good for 30whp, more aggressive up to 50whp. Figure $500 in parts, more in labor depending on who's doing it.

 

The lowest cost is weight reduction that creates a higher HP to weight ratio by simply removing stuff you don't need. You can ditch 100# in 30 minutes, which is effectively the same as adding 10 HP.

 

Just to add to this, the Vararam won't typically show up on the dyno. So it might appear to be a 0 HP/ $, but that wouldn't be an accurate judge of its value. It provides real world gains by helping keep the intake air cold, which really helps off-the-line at the track or from a stop on the street.

Good tires are another mod that adds no HP, but makes the car quicker off the line.

 

What can you remove to save 100 pounds? Passenger seat, targa top, floor mats won't add up to 100 pounds.

 

I would do the A&A supercharger kit. If you have extra cash get the headers as well. That setup is usually good for around 600rwhp with pretty much no maintenance and will drive stock.

 

Thanks, I appreciate the advice...but I've already gone the forced induction route and not looking to do that again on this car.

My car is double duty daily and road racing. Removed my blower and am now back to stock. All I have is exhaust now, but looking to add headers and mid-pipe, probably flex fuel system...and beyond that I'm not sure if it's worth anything else. I'm not power hungry anymore because it does really well on track with stock power...but am looking for ideas on what I can do to keep it N/A for more fun street use. I would only do that, however, if the HP gains are worth it relative to parts/labor cost.

 

Would help to know if LS2, or LS3 with stock parts.

The LS3 OEM intake is a good one that there is not much to be gained installing an after market one, while the LS2 OEM intake sucks due to the way it was produced, were something like a Fast intake does make a huge of difference isntead (not only the power you can at top end, but the increase in power through the entire RPM range as well).

 

If you are just trying to figure out the cheapest way to get HP, heres the cheapest way I found.
Tune - $600
TSP headers - $730
Nitrous - $2300
600HP - $3630
My nitrous kit had all the fancy stuff with it (dual bottles, billet holder, heaters, big show purge etc..) Could only spend around $1500 on a decent nitrous kit for the same result.

 

Thanks man, but no...not necessarily looking to add HP cheapest way possible.

I just wanted to know which N/A options exist..and a general price tag to know if it would be worth it.

For example, if you were to tell me that adding a cam would $4500 installed and might add 100 HP, while adding a supercharger costs $6500 installed but could add 150-200+HP..then obviously the supercharger is the better value. There are pros and cons on N/A vs forced induction obviously, but my issue is mainly lack of experience and knowledge. I have no idea what some of the N/A mods are or how much they cost. Thus wanting a guideline thread to help.

And I have an LS3. 2012 Base C6