gmanw54

Just curious what you guys thought. worth the money for the performance (or lack thereof) ?

YESHONEY

I assume you mean JHM or APR tune?

I have same question! I also have Milltek resonated on mine, so for the fun and sound factor its great! but it does zero for performance! Except save a little weight~

Joe

Greg5OH

JHM is the only real game in town. I will be doing it to my 08 S8 eventually.

gmanw54

yes, that's what i meant.

would love the milltek non resonated, it sounds amazing!!! just can't justify spending 2500 for awesome sound

so...is the JHM tune worth it? $700 worth it

Greg5OH

I don't recall how much just the tune does, but with long tube headers, 2.75" exhaust, JHM tune the latest beta S6 gained 100 hp and 120 ft lbs...7-8 mph faster in the quarter too.
big restriction are the stock cats, followed by the crappy manifold style "headers",

gmanw54

would it be worth it to do with no mods at all? i have nothing done, so should i even bother till i upgrade the exhaust?

ScottCNelson

..and only helps if you have 93 octane available. No aftermarket exhaust for an S8 has been proven to make the car any faster rather than just louder. If you're like most S8 owners, a carbon clean and IM replacement will improve your performance better than any tune and/or exhaust.

If you want an S8 that can be greatly improved with a tune, get a D4.

The most bang for the buck and fun per throttle application can be had with this:

https://www.sprintboosterusa.com/p-1...udi-a8-s8.aspx

dvs_dave

Greg5OH

Look it up on audi revolution.
Those are the claimed figures. I don't know haven't seen a dyno slip.
However there is an EIGHT mph gain in the 1/4. 1/4 mile MPH numbers dont lie. 4600 lbs weight, 118ish mph, that puts you right around 560 horse. EDIT: cant find the damn thread right now so don't take my word for it yet.


The key is definitly the exhaust. the s8 has manifolds with long secondary runners basically. cylinders 1,2,3 all dump into 1 tube, then 4,5 dump into one tube. check out the how cylinder 4 dumps out, it essentialy has to make a 90 degree turn 1" away from the head. Literaly the worst thing you can do for flow. In the self study guide Audi says a 5 into 1 equal length header would be ideal (which is what JHM is doing now), however the vehicle would not cert for euro or US sales without 600 cell per square inch cats and very close coupled catalysts for quick light off (also add in SAI).
going with a tuned header length coupled with a nice merge collector, also deleting those 600 cpsi cats would have a tremendous effect. Lots of drag racing articles show a 10-20 horse improvement just adding a proper arrow point merge inside the collector so the gases dont have such an aburpt termination.
Heck the JHM v8 S4 long tube headers show time and time again to be good for 50+ horse and 60+ tq...amazing gains for an exhaust upgrade!

I'm not vehemently defending the claimed numbers, but there is some serious potential to unlock.

I just gutted my cats but will be running a pair of 3" 200 cpsi cans. left the stock can shells becuase I didn't want to invest 10 hours of my time making a million pie cuts and welding them up on a crappy design manifold anyway. But I am expecting a decent bump in power. Never dynoed the car before, and probably won't dyno after either but the butt dyno will be able to tell a difference.

BASARAB

I contacted you on Audirevolution, have a different name there haha
I plan on getting JHM tune only just for the hell of it and we can race each other, to see if you are gonna be much faster with other mods ))