[oldman]

Originally Posted by AndyUK

I'm not trolling you, but you seem to not want to read what I've written and actually respond to it, creating your own argument along the way.
I've got you saying full exhaust and then oldman saying full exhaust is a strawman because its never going to be good bang for buck, so if my answers to both lines of enquiry are getting conflated and confusing you then I apologise. Lets get back to full exhaust only then;

I very clearly said that I wouldn't tackle a full exhaust and certainly not headers on my own, I don't have the space or equipment, a centri yes, but I couldn't get the car up in the air enough for me to want to do headers and exhaust. I also wouldn't do my own tuning, so theres that, although a centri does come with its own tune, so that isn't really a concern on that front.

no cats isn't an option for me, so its not $2400 its more like $3000, plus fitting and tuning because of the above

even at $2400 self install and tuning and assuming 30hp just from the exhaust, and assuming you already have a tuning device, that's still $80 per hp

so if you are going to ignore the cost of tuning and device, E85 becomes $375 for the sensor for 30hp... or $12.50 per hp

similarly ported TB and intake is $575 for 17hp or $33 per hp and YES both give good gains across the whole curve

a centri is $6000 for 150hp or $40 per hp even adding fitting its still only something like $46



your exhaust system, even giving you every benefit of the doubt is more than double any of these other add ons

in my personal case, and yes this is subjective, even going with the droney SW system, it is much closer if not over $4000 or $133 per hp, it just doesn't make any sense to do that before doing any or all of the above

if someone wants to do a full exhaust system "just because" then that is absolutely fine, but the guy who first said its not worth it from a bang for buck point of view was spot on

I think personal install cost varies and is situational. It would be better to leave it off. Even though heads and cam are clearly expensive to install.

Centri is the best but that is 150 HP and 150 torque with no warranty (same goes for any N20 claim). Parts fail at the torque level. I think if one is looking for performance for cheap and wants to drive it, a Centri, especially on a M6 is probably the most expensive mod imaginable over a 100,000 miles driving experience. Even with my projected setup FBO + heads and cam, I'm actively looking for: clutch, drive shaft, half shaft and LSD upgrade and would consider an entire Zl1 diff upgrade.


Partial bolt-ons the 6th gen are already in the 10s. I think PD at this point is merely for bragging rights at the car meet, clearly performance is limited by traction... or lack there of. So really the best bang for the dollar is a set of daily drag radials. Meaning as the Meta sits right now a A8 with FBO and DR is going to be a driver's race with anything that somebody would actually drive on a daily basis.

Car and Driver recently did a test of tires, DR, and slicks on a HellCat and the best they got was low 11s and the car was prepped and driven by competitive 1/4 mile guys.

I'm sorry but cars don't drive themselves, and at this HP level clearly it is more and more a driver's race and the best bet is on the guy with the stickiest set of tires on his "daily driver".


http://blog.caranddriver.com/whats-t...s-to-find-out/

Yeah, I already know they are scrubs and somebody's ma can put a Hellcat into the mid 10s with the same setup. I'm just saying right now A8, FBO, DR ain't losing to anything else on the street in 99.9999% of the potential street fights. Not some make believe TV show like Pinks...


Put it this way, I once said my LS1 has killed every Supra I've ever raced. Sure enough 20 emails and post come in challenging me to a race for somebody or others "daily driver" 1000 HP Supra.
1) Claim I beat every Supra I've raced, is not a claim that my car is faster than all Supras.
2) Note the claim of "daily driver" varies widely and as Hot Rod has shown in the pump gas shootouts going for more than a decade many of these streetable car (an even looser claim), can't even drive a 60 mile test loop before failure.

Yep Centri is great bang, but there are issues with that claim
1) real world performance based on the tires that are actually on the car on a daily basis
2) drivetrain issues over the log run, meaning cheap ain't cheap

Did I run DR on my LS1? yep, have I run DR on some of my other "daily drivers"? yep, do I see DR at the local car meet? yep. How many? About 1% to .1%. So what are the guys with FI doing? Simple hopping they pick on lesser cars and hopping said car does not have a set of DRs under the fenders. Oh and we are not talking 00 rated DR, more like 80 or 100 wear rated Nittos.





Just my .02.