Just a general question about what is the most hp achieved with bolt on's on a new 3.8 NA motor? I see there are many good boltons plus tuning, just wondering if anyone has done them all and what the final outcome was. I searched under horsepower, but of course came up with to many links.
thanks

 

You've got one heckuva can opener- hope you like worms! If people take the bait, this could be interesting.

So, my $.02: A supercharger is the best way to add RWHP, and is simply the best $/HP modification you can do.

You could spend a lot of money doing all the other "usual suspect" mods, and I've done most of them, including: custom ECU flash, full exhaust with 200 cell cats, Plenum (if you believe the hyper or are willing to test it), LWFW, cold air intake, etc. All that will add up to about $8,500 or so if you do the installations yourself. I won't even speculate on what the HP gains that would provide. I have those mods, and am going to be dyno'ing and G-testing within the next couple of weeks.
CATTMAN

 

I'll nibble..
My guess is going to be around 390hp...I have seen several cars now that have put down near 340rwhp. These cars were what I call the X51 light cars. They had full a full X51 package minus the heads but with sport cats and software. This means the X51 intake manifolds, plenum, throttle-body and X51 intake along with headers, cats and mufflers. This all tied in with software. There were several European tuners that I was in touch with that offered basically this package.

I believe a full exhaust on its own is probably only worth 15-20rwhp and this will get you most of the way there. The other 15rwhp is going to have to come from the intake side and software.

Dave

 

Depends on how much HP you will be happy with. +1 on the supercharger but that will be an expensive proposition. Great HP and TQ but not quite a "bolt on". It takes a good deal of time to install and ecu would need the corresponding flash and they do get best results with full exhaust.

Otherwise, IMO, quickest solid gain would be a std software flash. Second best quick gain an EVO cold air intake. Exhaust has good gains but cost goes up VS the first 2 upgrades. and not as much HP.

 

ok, first let me say that I am not hoping to stir or start anything here. In fact, I normally don't frequent this specific forum, but am interested in seeing how high an NA motor can go. I know doing an SC or turbo can get you there, but I am speaking specifically, of things like headers, cats, mufflers, intake, IPD plenum, TB's and tuning, lwfw, etc. The 3.8 is at 385 bhp right? So with all these mods would not a realistic 30-40 bhp or so be attainable? Putting the motor at around 425 bhp, right on with the GT3? So 360 rwhp or so?

 

I was thinking the same thing.

 

I don't agree, I have had a flash on my first car and had the EVOMS intake on both cars. I felt as if there weren't any gains with these mods at all. LWFW and Hi Flow Cats are the two biggest IMO.

 

ok, in the interest of not starting any trouble, if you all think that this is a trouble starting thread, I will ask the mods to close this thread. My intent was not to start trouble in here, I do apologize.

 

The 09 3.8 is at 385hp...My input is based on a 997S Mk1.

Dave

 

Ed, I agree. LWFW and Cats made the most difference as per my butt dyno.

In terms of starting trouble, don't be silly, it's just that this topic gets a lot of interest and debate. Sit back and watch it unfold.

My car is 997.1, so stock it started at 355hp at the crank. Should know soon what the mods I've done have added, but I will be measuring RWHP.
CATTMAN

 

It won't be trouble, it will just be a repeating debate that has happened before.

 

ok, cool. These motors seem to have lots of potential. Even going into the internals and doing headwork and cams, of course that becomes quite expensive with the p-car premium.

if you can gain a 50 bhp from these motors without going to SC that is incredible bang for the buck.

 

I've got a plenum and the full AWE exhaust (headers, cats, mufflers). I haven't dyno'd the car and I'm kind of bummed that I never did a before "mod" dyno. Anyhow, my butt dyno tells me that I've got a bit of a pick-up but nothing to put down on paper.

 

I doubt that you can get 50hp from bolt ons. I would think that maybe about 40 max, but as you said it will be expensive, $100-150 per hp

 

"LWFW and Hi Flow Cats are the two biggest IMO."

Please excuse my ignorance....but what is LWFW?