Ducati Testastretta / Valve timing

Post by **Doggo** » Wed Jun 17, 2015 9:10 pm

Following on from discussion on Wurly's AEM v1 vs v2 thread, and Nath's comments on inlet manifold tuning, I'd been reading about the role of valve overlap generally and came across this.... well, I thought it was clever...

....

http://www.ducati.com/en/testastretta_D ... x.do#start

I guess maybe this is more new to bikes than cars.

mercutio · Post by **mercutio** » Wed Jun 17, 2015 9:15 pm

Damn clever these Eyetalians

Post by **Doggo** » Wed Jun 17, 2015 9:19 pm

Indeed. What surprises me is that Ducati seem to be reliable these days too

hondaman · Post by **hondaman** » Wed Jun 17, 2015 10:17 pm

Ducati have been using gear driven cams since god knows when, the 70's at least, this new DVT is pretty clever though, but don't forget that Honda have had vtec on the VFR800 since about 2002-4 I think it came in, having ridden a vtec VFR though it doesn't feel as sophisticated as the vtec car engine, imho.

never ridden a testastretta engined Ducati, but a mate had an early Multistrada 1200 for a while and says its to much sportsbike power delivery in a touring chassis, hence why he sold it and bought an RC8

Post by **Doggo** » Wed Jun 17, 2015 10:25 pm

What got me was the timing adjustment possible, as opposed to the Honda system of (As I understand it) just the two fixed cam profiles.

Shame you had to sell the 929, btw. I've not ridden one but 3rd Gen Steve tells me they're good.

Lucky chap, moving to an RC8!

hondaman · Post by **hondaman** » Wed Jun 17, 2015 10:31 pm

Doggo wrote:What got me was the timing adjustment possible, as opposed to the Honda system of (As I understand it) just the two fixed cam profiles.

Shame you had to sell the 929, btw. I've not ridden one but 3rd Gen Steve tells me they're good.

Lucky chap, moving to an RC8!

Cheers bud, Its a temporary thing, once my hand is better I'm getting another GSXR1000K5 or K6 had a K5 a few years ago, (wish I'd never sold the K5 tbh) before the 929, which was a temporary change in its self, the reports how awesome the 2005- 2006 GSXR is, don't lie.. its completely mental

3rd gen steve · Post by **3rd gen steve** » Thu Jun 18, 2015 9:29 am

hondaman wrote:
Doggo wrote:What got me was the timing adjustment possible, as opposed to the Honda system of (As I understand it) just the two fixed cam profiles.

Shame you had to sell the 929, btw. I've not ridden one but 3rd Gen Steve tells me they're good.

Lucky chap, moving to an RC8!
Cheers bud, Its a temporary thing, once my hand is better I'm getting another GSXR1000K5 or K6 had a K5 a few years ago, (wish I'd never sold the K5 tbh) before the 929, which was a temporary change in its self, the reports how awesome the 2005- 2006 GSXR is, don't lie.. its completely mental

The 929 was an awesome bike, one of my favourites. Ive always wanted to try a k5, they are supposed to be one of the all time greats!

How does your friend find the rc8? I was in my way to trade my hayabusa for one when it started misfiring, nearest port of call was my local honda dealer where i get most of my bikes from. When i went in they were just putting a a price tag on an ex honda uk 2010 fireblade. Never made it to the KTM garage.

hondaman · Post by **hondaman** » Thu Jun 18, 2015 9:41 am

3rd gen steve wrote:
hondaman wrote:
Doggo wrote:What got me was the timing adjustment possible, as opposed to the Honda system of (As I understand it) just the two fixed cam profiles.

Shame you had to sell the 929, btw. I've not ridden one but 3rd Gen Steve tells me they're good.

Lucky chap, moving to an RC8!
Cheers bud, Its a temporary thing, once my hand is better I'm getting another GSXR1000K5 or K6 had a K5 a few years ago, (wish I'd never sold the K5 tbh) before the 929, which was a temporary change in its self, the reports how awesome the 2005- 2006 GSXR is, don't lie.. its completely mental
The 929 was an awesome bike, one of my favourites. Ive always wanted to try a k5, they are supposed to be one of the all time greats!

How does your friend find the rc8? I was in my way to trade my hayabusa for one when it started misfiring, nearest port of call was my local honda dealer where i get most of my bikes from. When i went in they were just putting a a price tag on an ex honda uk 2010 fireblade. Never made it to the KTM garage.

He absolutely loves the RC8 has wanted one for ages, I spotted it on the interwebs at a car dealers going for a song, went to have a look and the rest is history... the suspension was way to firm, when he got it, but I've sorted that for him, and now he just loves it, I might even get a chance to ride once my hand is better,

Your right the 929 is a brill bike, the 954 was better ihmo, faster (slightly) more comfortable, better handling, which probably explains why Tadeo Baba has a 954, even better than the first underseat pipe CBR1000 Blade which I've also had, I've not ridden the later 2008-on Blades so don't know what their like, but a mate has the limited edition one with Ohlins and the like and loves it, and has just come back fro ma 6 day trip to Germany and back on it, without aches or pains, which I find amazing, considering the seat is made of wood... well almost

Being a bit of a Honda man myself, was amazed at how good the GSXR thou K5 was, its like a 954 Blade with a rocket up its chuff... the reports are true, its truly the best litre sportsbike I've ridden or owned sad to say this, but better even than the SP1 I had, which I absolutely loved, but was way to uncomfortable on long runs, even though it handled slightly better than my sorted K5 thou, where as the K5 was in its element touring, scratching (meaning trying to rip your head off) or going down the shops, which is why I'm getting another soon as...

Post by **NafemanNathan** » Thu Jun 18, 2015 12:04 pm

Interesting! I wonder how that actually achieve it... Physically, what with both parts rotating constantly.

From this...

The system can continuously vary the position between the camshafts and the crankshaft in the range between minimum and maximum overlap. Furthermore the system has the ability to independently vary the intake and exhaust cams, resulting in an infinite number of possible configurations. The ECU mapping has been developed to select the position that optimizes power delivery, torque, smoothness, and fuel efficiency for the rider’s every throttle command.

... Are they trying to imply the ECU thinks for itself to decide on cam position as aposed to a map?

I imagine a big variet would be air temp, so from a fast revving race/performance point of view, I do wonder how much it would actually effect the end result (Torque curve and acceleration). Obviously it needs to re-adjust for every change throughout the rev range, but then considering how fast you actually go up through the revs, is it going to be worth while adjusting? Because no doubt as soon as it's adjusted to suit it's already going to be in the next rev range and needing to adjust again.

I can only really imagine this concept to be of any use at cruising speed (So it certainly has it's use!), where it will have time to adjust and the speed maintained. It can adjust when accelerating underload to give additional torque gains as well, and you'll achieve the most economic fuel consumption.

Post by **indigolemon** » Thu Jun 18, 2015 12:10 pm

Looks similar to the system used in my Volvo: