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These charts illustrate the difference. It's the area under the curve - so you're feeling the delta in HP and torque over a rev-range. These charts are NOT traditional HP and torque curves. They show the variance between Stage 1 vs Stock (left) and Stage 2 vs. Stock (right). Notice how much higher the torque difference is (white line) Stage 2 vs. Stage 1. Huge. The reason is that with Stage 1, you've created significantly more airflow under WOT and the stock exhaust isn't designed to handle that velocity of airflow. Tuning the exhaust to match the engine performance "frees" up potential power, allowing that animal to breathe (think of the stock exhaust as an exhaust restrictor plate - not dissimilar to the intake restrictor plates on carburated race cars to normalize engine outputs).
Left = Variance Stage 1 vs. Stock Right = Variance Stage 2 vs. Stock
The Graphs show the engine is running out of turbo. That is why it drops so fast at the top. These engines (ECMs) have so much built in safety it retards timing and add in fuel - which also hurts power. That is why it is hard to get these cars to repeat a big number on the dyno. and that is why the stage 1 has the biggest gain - simply put even in stage 1 APR ramps in the turbo - pronto. then is stage 2 with freer flowing exh - you get that "delta" boost under the curve but not so much "peak"
Torque talks. I would trade 30 ft.lbs for 30 HP on the street any day. HP is top speed, Torque is acceleration
so ive been driving around with stg2 and I really dont feel much of a difference off the line but its definitely feels a little stronger after 60mph. i recently bought a dragy unit and been testing and 0-60 is 3.2 and 1/4 mile is 11.31 which really isnt that much faster than my stock s8. stock it did 0-60 in 3.3s and 1/4 mile in 11.33 but of course it is an s8 plus so only does that in the overboost senario.
60-130 on stg2 was 8.75 vs stock at 9.5 so midrange is obviously definitely stronger but down low just isnt different enough...im going to take it back to the shop to see if they did something wrong but if this is it then im getting a refund.
hopefully someone is going to do something better for the s8 plus as I want to really get into the 10's. also anyone know if someone out there makes a stiffer swaybar and stiffer suspension items? everything is so loosy goosy up in the front.
I hear ya on the need for sway bars. I recently lowered by 17mm (all corners) using VCDS and it made a noticeable difference in terms of body roll - a nice compromise without losing the benefit of having a smooth ride. Please keep us posted on Stage 2. What you're stating is disappointing and seems to be contrary to what others have said so I'm hopeful that something is awry or that the ECU hasn't "learned" yet.
APR illustrates running 11.174 on 93 octane for Stage 1 and breaking into 10s with race fuel (100 oct). I would think that Stage 2 should make this a 10-second car on pump gas under reasonable conditions (temp/altitude). Maybe add the intakes that are discussed on the D4 forum to ensure it? How much torque can the tranny handle anyway? We have to be approaching the reasonable limits of this car without falling into the never-ending cycle of upgrades. If it's about reducing 1/4 ET, weight reduction is probably where I'd start looking since this thing is a pig.
I hear ya on the need for sway bars. I recently lowered by 17mm (all corners) using VCDS and it made a noticeable difference in terms of body roll - a nice compromise without losing the benefit of having a smooth ride. Please keep us posted on Stage 2. What you're stating is disappointing and seems to be contrary to what others have said so I'm hopeful that something is awry or that the ECU hasn't "learned" yet.
APR illustrates running 11.174 on 93 octane for Stage 1 and breaking into 10s with race fuel (100 oct). I would think that Stage 2 should make this a 10-second car on pump gas under reasonable conditions (temp/altitude). Maybe add the intakes that are discussed on the D4 forum to ensure it? How much torque can the tranny handle anyway? We have to be approaching the reasonable limits of this car without falling into the never-ending cycle of upgrades. If it's about reducing 1/4 ET, weight reduction is probably where I'd start looking since this thing is a pig.
These numbers represent 556 - stock to go 116.7
651hp to go 123 mph
and
701 to 126 mph
701 is nearlt exactly what my car makes so it all seems pretty darn close. As for ET. cant tell you
What would be the downside to having a stiffer swaybar? And yes it's pretty sloppy in dynamic mode... Firmer but still sloppy
I can't think of a downside other than it stiffing up the ride a bit. But the reduced body roll would be worth it. I asked my Audi service guy (certified APR dealer) to look into upgraded suspension parts, specifically sway bars, for my S8 and he didn't come up with anything. I understand why - who would produce something like this for a low production car where most owners don't fall into the "tuner" category. I'm sure a racing shop would gladly whip up a pair for the right price.
I'm far from an expert in suspensions (quite frankly, I'd only extol myself as an expert in the love of Audis, technology and cars in general), but there's something weighing on me. I stepped out of a 2015 S4 and into a 2015 S8. Big jump from every perspective. A primary attribute about the S4 that I miss about the S8, is the feeling that I can take a turn without the feeling that the car is going to roll on me (yes, I'm exaggerating). The secondary attribute is the instant torque where I feel I could have taken any car 0-60 feet (supercharger vs. big turbos). Don't get me wrong, not for one second do I wish to have anything else than the S8.
To further this discussion, on the same day that I bought my S8, my wife picked up a 2018 A5 cabrio (traded in her leased 2015 A5 cabrio). I liked her B8 A5 but the driving dynamics of the B9 blow it away. I just drove it again yesterday for the first time in a while and can't get over how smooth it is and how well it handles. It actually feels better than the S8. I hate admitting this - just honest with myself. I drive the A5 and think to myself, damn, this feels perfect. Perfect is subjective but I'm referring to the balance of performance and comfort.
So, what's going on? Maybe I'm dealing with a lighter, lower center of gravity car? Maybe it has updated suspension technology? Maybe it's designed to be more of a touring car vs. an Autobahn crusher? Granted, I'm not taking turns at 60 mph, I'm talking about daily driving albeit more aggressive than most drivers. I'd love to hear from someone who has more technical knowledge on this subject.
Last edited by dgbaudiphile; 05-28-2018 at 07:22 AM.
Yes, stiffer sway bar will stiffen general ride too. But S8 bars are as stiff as you can get from factory and as mentioned, no volume aftermarket for likely support by a third party vendor. Stiffer rear bar typically dials out some understeer the factory settings end up with on most front heavy vehicles, but again with S8 no further bar is available.
S8 is a heavy car--frankly at least 500 pounds overweight. They went the wrong way on both the D4 and now D5, each time stepping up the pork from prior generation. Relative to last reply, my reaction on first driving the D4 S8 was similar, and that is coming out of the basically same weight D3 W12. Love power, but dynamically a bit unsorted, and yet more odd since comparo was a LWB. The change that worked for me was offing the factory 21" boat anchors. Pig heavy cast, to go with rest of car weight I guess. I switched to factory 20's--still in 9's with a 275 tire. Not so much to soften ride but to get rid of the unsprung weight. The worst kind too--both unsprung and rotating mass. 9 pounds a corner was removed. More unsprung weight savings than the D4 CCB's as another comparo, yet cost per pound liposuctioned is way smaller. While a little softer, ride actually feels crisper and just better dynamically. In theory it helps acceleration and MPG's a bit too, though that part is very modest. No personal data to back it up, though for the UK factory wheel choices they now have to publish fuel economy/CO2 for each wheel choice. That data suggests it is 1-2%.
Still happy with it two years later. Not a dramatic delta, but noticeable. Could do the same thing in theory with a quality forged 21. But there are no factory forged 21's and aftermarket those are the uber pricy wheel sets that get to $10K, or even $6 or 7K used. I got a clean OE wheel set for around $1500, plus tires after that. Even among the forged choices, there is a couple of pounds difference. I used the twin 7's to get to the lightest type and look I like. Referred to as "new style" RS6 actually (old ones being the polished bigger spoke 9's). The 10 spoke double ones found on a lot of D4 A8's are a few pounds more but easily found used and clean for yet less.
Yes, stiffer sway bar will stiffen general ride too. But S8 bars are as stiff as you can get from factory and as mentioned, no volume aftermarket for likely support by a third party vendor. Stiffer rear bar typically dials out some understeer the factory settings end up with on most front heavy vehicles, but again with S8 no further bar is available.
S8 is a heavy car--frankly at least 500 pounds overweight. They went the wrong way on both the D4 and now D5, each time stepping up the pork from prior generation. Relative to last reply, my reaction on first driving the D4 S8 was similar, and that is coming out of the basically same weight D3 W12. Love power, but dynamically a bit unsorted, and yet more odd since comparo was a LWB. The change that worked for me was offing the factory 21" boat anchors. Pig heavy cast, to go with rest of car weight I guess. I switched to factory 20's--still in 9's with a 275 tire. Not so much to soften ride but to get rid of the unsprung weight. The worst kind too--both unsprung and rotating mass. 9 pounds a corner was removed. More unsprung weight savings than the D4 CCB's as another comparo, yet cost per pound liposuctioned is way smaller. While a little softer, ride actually feels crisper and just better dynamically. In theory it helps acceleration and MPG's a bit too, though that part is very modest. No personal data to back it up, though for the UK factory wheel choices they now have to publish fuel economy/CO2 for each wheel choice. That data suggests it is 1-2%.
Still happy with it two years later. Not a dramatic delta, but noticeable. Could do the same thing in theory with a quality forged 21. But there are no factory forged 21's and aftermarket those are the uber pricy wheel sets that get to $10K, or even $6 or 7K used. I got a clean OE wheel set for around $1500, plus tires after that. Even among the forged choices, there is a couple of pounds difference. I used the twin 7's to get to the lightest type and look I like. Referred to as "new style" RS6 actually (old ones being the polished bigger spoke 9's). The 10 spoke double ones found on a lot of D4 A8's are a few pounds more but easily found used and clean for yet less.
Thank is the price we paid for AWD. To get all that drive train up there they had to hang the motor farther forward. I think the car handles great. Great compared to other cars like it. Not great compared to my R8 or Z06. Its on par with S63 and way better than the M760 I drove before buying this. I guess its all relative
Thank is the price we paid for AWD. To get all that drive train up there they had to hang the motor farther forward. I think the car handles great. Great compared to other cars like it. Not great compared to my R8 or Z06. Its on par with S63 and way better than the M760 I drove before buying this. I guess its all relative
I hear you S4G. Thanks for reminding me that, at worst, it's on par with its direct competitors. Evokes that you can't have it all (at least in one car). Have a 911 in my sights to provide me the other end of the driving experience spectrum.
05-21-2018, 08:55 AM
