Bolt on Mods...Do they REALLY make a Difference?

Well the title says it all...Bolt on Mods, Do they REALLY make a Difference in actual performance numbers? I just picked up a 03 C4S, and since I have been "converted" from Vette's I do sort of miss the torque (but only until I really start driving this refined beauty ). Is there any way to increase in this area? I would also not like to void my warranty....What are my options? Thanks BTW, I really appreciate all the info i have gained before my purcahse from all of you gays/gals

GAYS.................?????? Well, I guess....

Read the end of the thread on the 40th anniversary that discusses x51 vs standard. In my opinion there are no bolt ons that make any significant difference. The only one to consider would be a supercharger for about $11K.

Excellence magazine had an article a while back that basically echoed mrpc12's thought - they said the 996 doesn't really lend itself to engine perormance improvements through bolt ons. Porsche changes a bunch of parts with the X51 to get 25 HP - if they could do so in an easier fashion I would expect them to take that route. The 997 gets a 5 HP bump in the 3.6 motor with some induction revisions, but to really pump up a 996 the supercharger is probably it.......

The general consensus is that with the 996, Porsche isn't leaving much on the table in terms of untapped power. It's not like the old days, when simply changing to a "free flow" exhaust or whatever would significantly increase power. With the 996, some of these bolt on mods may actually REDUCE power. (For example, Alois Ruf states that it took a lot of tuning to ensure the Ruf exhause didn't cause a loss in power.)

Thanks to ALL of you for the info..... I really like this car!! The more I drive it, the better it is....and the less I miss my...?? I used to have a..Z0...What? Oh well, it's gone...

The 996 supercharger has been featured in four magazines now and all of the magazines gave the superchargers good reviews. Click here for a link to the website which has the magazine articles and more info on the superchargers: http://www.evoms.com/p%20996%20SC%20upgrade.htm Let us know if you get one. I'm considering having one installed also.

WOW!...those specs look pretty impressive!. Anybody know the cost & reliability? I bet that baby flys!....Thanks again to you all for all the info for the "new-Porsche-guy" and all my questions!

Not sure about the 996, but many Boxsters with superchargers have mysteriously blown, no warranty on a s/c engine. I would be leary for long term reliability. The extra internal forces on the engine can be fatal if the engine was not designed to handle it. The Turbo uses a completely different motor in part to handle the additional stress of forced induction.

i haven't heard of any problems with a s/c on a 996 engine. there's a few guys on this board with one and they seem very happy with them!

question on fab speed they claim a decrease in 0 to 60 time of 0.4 seconds with exhaust change is thos wishfull thinking or realistic anyone with this mod and experience

While I did not read the Excellence article, it's clear that the X51 option does not increase tq, and indeed moves it up the rpm range. tq is what we 'feel', so that's probably why folks are somewhat lukewarm on it. On the track, the extra hp up top would be nice though, as these cars tend to have a weak top end, especially compared to the way the E46 M3 delivers power up top. I'm not very experienced in the Pcar world, but coming from 10 years of BMWs, the big issues with centrifugal-based aftermarket blower kits has always been: 1. Heat soak. Cars have been shown to drop massive amounts of power running in hot conditions or back to back dyno runs. On the plus side, it appears that evo is running a proper intercooler (air/water) and adds extra cooling capacity. 2. Virtually no increase in performance in the bottom half of the rev range. This is intrinsic to centrifugals, as max boost in *only* made at redline, and boost and rpm are *not* linear. IIRC, you will only see 1/8 of max boost at 1/2 redline. So, at roughly 3500 rpm, you'll get less than 1 psi. Up top, a well done kit will pull like a freight train. I'd be very interested in knowing how these kits hold up on hot tracks, under extended running conditions, as magazine review testing generally do not duplicate such extreme conditions. (like a 1 hour run session at 100 degrees on Rcomps) Just my 0.02. EDIT: Talked to Evo today. Their kit has not really been track tested. It sounds like a robust kit, but I'd be a bit cautious if you do track events.

Solsavr - you might try a lighter fly wheel. From what I've heard its allows the car to rev quicker...people on this board have nothing but good things to say. Doesn't make it easier to stall, and should improve excelleration. If you look at the video on EVOMS site (the one from in the car), that is Ben in LJ's car, and he has a lighter fly wheel (as well as SC), but look at his tach...the needle flies around the dial..

In my experience (but not on a pcar), ltw flys add NVH. Most manufacturers use either a dual mass fly or a sprung hub clutch disc to damp vibrations, but at idle and while you rip through the rpms. On bmws, flys add a rattle at idle, but the posts on this board indicate that there is no idle rattle on 996s. However, I'm betting that there is increased NVH through the rev band. Can anyone comment?

yeah. what does NVH stand for?

Automotive term: Noise, Vibration, Harshness. With the ltw, single mass fly on my M3, the smoothness of the power delivery is diminished; the engine is rougher. More noise too at certain rpms. I doubt there is anything special about the boxer engines that make them immune to negative impacts of ltw flys. EDIT: But I hope I'm wrong.

I've heard there are 2 brands of ltw fly wheels, one from FVD the other from EVOMS. At idle, no noise from FVD...haven't heard/seen for myself tho...

Indeed, the X51's extended torque range is a hoot at the race track! The peak is about 500 RPM later than stock, but it also stays at peak longer and drops off slower. All in all, a very nice, high performance torque curve.

Hell yeah. Don't get me wrong. I'll likely add the X51 after I get some track time in in the C4S, and feel the need to change a perfectly great car into a perfectly marginally better car. The only thing that could change that is some better data on the blower kits. For now, I remain skeptical and would just assume stay n/a. I do think, however, that money is better on suspension, some BlInG street wheels, and some track rubber on stock wheels. pstoppani, how do you like the Porch on the track vs. the venerable M3?

I think the supercharger is the best bang for the buck... Robert

So far my 911 is bone stock, so compared to a stock e36 M3, the 911 blows its doors off. My M3 is exclusively a track car with a Dinan SC, Moton coilovers, roll cage, blah blah blah... So, it handles much better than the 911. This is mainly because in stock form the 911 pushes like a pig and I've had it only on street tires (I run Toyo RA1's on the M3). Still, even with the supercharger on the M3 (rated at about 360HP), the 911 with the X51 package accelerates noticably better. While my M3 has had 21K miles with the supercharger, several thousand of which are track miles, I wouldn't do a supercharger again on a car that I planned to use at the track; especially a 996 motor. In the end though, they are very different beasts in terms of handling and power delivery. While the M3 is the eaiser car to drive fast, I find the 911 much more rewarding and entertaining. It's fun to switch back and forth between track days

Pete, one more question since I'm new to this Pcar thing after years with bmws. . . Is there a common route to dialing out understeer, while maintaining good street behavior? Let me clarify. After having gone far (but not quite so far as you) with M3 mods, I've found that certain involvement and subtleties in the handling and chassis vanish. Adjustable coilovers, solid bushings, aggressive alignments, etc etc tend to diminish the driving experience on the street IMHO, while gaining more performance from 8/10's to 10/10's on the track. For this reason, for suspension I wanted to go with the X73 setup from Porsche to maintain the same involvement as a stock car, but sharpen things up a bit. I'm not too interested in 100 way adjustable upside down penske/JRZ/Moton dampers with zillion rate springs. This leaves me with camber and tires to play with. I'm wondering if I could simply add in camber plates, get a good 2 degrees up front, and basically leave the car alone otherwise? thanks.

Pete, You should look into upgrading the suspension, US cars are actually higher than their RoW counterparts cause of some US bumper height law...so the susp out of the box isn't what it was designed to be. RoW M030, X73, or PSS9 should make it handle appreciably better.

The anniversary model comes standard with sport suspension, although it looks to be US M030. Same damping/stiffness as ROW, just a bit higher. I doubt slight lowering will reduce understeer. Could be wrong though I still think that the stock setup is camber challenged. I could only get -0.5 up front. I think that at least -1.5 will be needed for track/autox use, particularly since the front is a strut suspension that doesn't have the camber curve of A arm suspensions.