AndreCT

I had the distinct pleasure of meeting up with Andy and his C4S which has had the FBL kit done. The kit consists of exhaust, X51 airbox and reprogramming of the chip.. (Andy please chime in here to more fully explain).

Andy posted his impressions of the car in an earlier post.

I have the "regular" S with the X51 kit and here are my initial impressions:

Sound: we both had our sport buttons on and my car sounded typically "Porsche" like at all rpm's. I do not know if the sport button actually made any difference to Andy's car due to the FBL exhaust but his car sounded deeper at lower rpm's and then got raspier, like mine, at higher rpm's. When I drove his car I found myself blipping the throttle to get the sound into the cabin. It sounded really good. I could hear the air intakes sucking air at the upper rpm range unlike my car where I cannot detect that (am I used to it?) at all. His tailpieces are a work of beauty. 4 very clean pipes.. nice and large.. whereas mine are 4 dirty slightly smaller in diameter pipes. Anyone that knows Porshes will immediately spot the aftermarket exhaust.

Power delivery: In a non X51 car most will agree that the car runs out of revs the higher up the counter you get. The X51 corrects that and she is a rev happy monster. If there is one area of improvement it would be in the lower rpm range where she feels a little sluggish. this is not to say that she is a slouch just that the higher up the rev range the more the car feels alive. The power delivery is mostly linear with no real flat spots or areas where a "surge" of power might be felt. In contrast the FBL has a distinct surge at approx 5,500rpm's. Not turbo lag like where suddenly power comes in almost unexpectedly, but that is the best way I can describe it. It is not unpleasant at all.. just different to my car.

$17k versus $10k: We had a few "high speed" runs, pulling from 30mph to higher speeds (leave it at that) and in fairness to both cars (we each drove our own and then swapped drivers) I could not say that any one car was dominant over the other. My car did feel less settled at higher speeds than Andy's which made me wonder about suspension settings and whether the C4S has a different geometry than its 2 wheel drive sibling. Perhaps other more informed folks can help?

Conclusion: For less than 2/3rds of the price of a X51 the FBL kit appears to be a bargain. I will not comment of the potential loss of factory warranty because I do not know if that is the case or not but I do know that if I really wanted to get all of the X51 power and did not get it from the factory I would seriously consider the FBL kit. It looks really good, sounds fabulous and easliy is the equal of the X51 on the road.

Andy, it was a treat. Good luck with your car!! Please post your impressions too.

lthatch

Nice write-up. Thanks.

Nine9Sixer

nice comparo. thanks. tough research, but i suppose someone had to do it ; )

in my mind, especially when buying new, not messing with the factory warranty would prolly be enough justification to pony up the extra cash. but if i had a car that was midway or towards the end of its warranty, FBL sounds like the way to go.

curious: what roads did you drive for your testing today?

awilks

Andre, thanks for posting on our "drive" today. It was nice to spend a couple of hours with another 911 enthusiast. We took a ride from Darien Ct up the Merrit Pkwy to the Rte 7 connector, over to Norwalk, and used the connector as our loop for a couple of spirited runs. Seeing your car reminded me why black is still the best looking color for a 911 in my opinion.
My observation in the back to back drives was that it was hard to feel any major difference between the two cars. I do feel there is a little extra punch from the 5-7k rpm range w/ FBL kit vs the X51, and as we discussed there was a little more bounce in the suspension at times in your C2S. Does anyone on the board know if the C4S is slightly lower than a C2S? Andre and I thought we might have noticed that when we had them parked side by side, and that might explain the slightly more planted feel of the
C4S you described. If you get time to post the photo of our 2 cars from behind, it was cool picture, and would also show the differnece in the FBL tips vs the sport exhaust on your X51...till next time

MartyB

I assume both of you guys have driven a stock C2S/C4S. Given that you rate the X51 and the FBL package similarly from a performance standpoint, I'd like to know how obvious the difference is between your cars and a stock S?

Nine9Sixer

according to my 911 brochure, both cars have the same height. perhaps the difference in suspension feel was actually a matter of the ~120lb the 4S has over the 2S, which i understand would be in the front-- making the front feel a bit more bouncy.

AndreCT

Here is a picture of the two cars. It is difficult to "see" the small variance in height yet both Andy and I think the 4S is a slight bit lower. Notice his double shotgun exhausts, both the same size versus the PSE (in my case filthy dirty).

AndreCT

I have not driven a stock 911 recently. The last time I did so was at a Skip Barber Hi-Po driving school at LaGuna Seca almost two years ago. As I recall there was very little difference to distinguish between my X51 car versus the "stock" car except in the upper RP range where my car breathes better and was very happy to rev both higher and faster translating into better upper rpm performance.

Here Andy can better describe his feelings since his car was "stock" before the FBL mods.

And if he does not see this in a timely manner he did post his observations in a post on the board.

Deanski

Damn I must have missed you guys today!

The Rt7 connector is also my little "test" area as well seeing I live very close to it.

Next time, try the one going to New Milford from Danbury, that's another great open road.

Maybe one day we can all get together and see/hear the difference.

I'm glad it turned out to be a great day!!

Deanski

adfsouth

Great info/comparo Andre.....threads like this are why I love visiting RL


Beautiful rides!

mdrums

Thanks to both of you guys for getting together and doing this. Great way to make friends!

Holli82

+1

Sharing information like this is what makes the internet worthwhile

lig

Nice writeup.

I'd consider going f/i if I were to spend that much on mods that could possibly void my warranty.

awilks

One last comment on difference in our respective cars...Andre's factory sport shifter was my one (last) mod to make my C4S perfect. It was so noticeable in terms of the decreased throws, and overall sportier feeling of shifting vs the stock unit in mine. I highly reccomend the sport shifter for those interested in the aftermarket option or on fence when ordering new.

Deanski

Hey, next time you two want to try this again, give me a PM, I'm game to see the FBL mods and X51 together.

BTW, I hope you guys make it to the April 8th CVR monthly meeting at Danbury Porsche.

Deanski