Dyno after ETG tune and pulley
#22
05-31-2016, 08:19 PM
Veteran Member
Yes, stock... (That I am aware of)
BTW: is there any way to prevent kick-down? We wanted a 2K and up chart, but with all the nannys turned off, sport and manual, it still kicks down if you floor it at 2kRPM. Maybe I've missed something in the manual? I know it will not automatically up-shift like my '07, but I guess I assumed it would not down-shift except maybe with your foot off the pedal rolling to a stop.
V
BTW: is there any way to prevent kick-down? We wanted a 2K and up chart, but with all the nannys turned off, sport and manual, it still kicks down if you floor it at 2kRPM. Maybe I've missed something in the manual? I know it will not automatically up-shift like my '07, but I guess I assumed it would not down-shift except maybe with your foot off the pedal rolling to a stop.
V
Last edited by CleverName; 05-31-2016 at 08:25 PM.
#23
06-01-2016, 12:34 AM
Not intending to thread jack, but I'm headed in Friday to have the induction system cleaned (BG44), and like Q&C I wanted to know my starting point.
So here is the chart for my new to me XKR, and I'll do a follow-up shortly after the cleaning for comparison.
My XKR has 30Kmiles on it now, and no clue what to expect from the cleaning, but no harm no foul...]
So here is the chart for my new to me XKR, and I'll do a follow-up shortly after the cleaning for comparison.
My XKR has 30Kmiles on it now, and no clue what to expect from the cleaning, but no harm no foul...]
Last edited by rfr66; 06-01-2016 at 12:51 AM.
#24
06-01-2016, 12:58 AM
Veteran Member
I have had a couple direct cylinder injection motors in the past and this problem has been a Achilles heel to most of the industry.
Pretty sure Jaguar now recommends the cleaning process.
Lexus got around the issue by keeping one injector in the intake runner, so full throttle washed down the valve stems. Audi is dodging law suits for lost HP for similar problems.
If I note any significant change, then I will probably add a water injection system which can mitigate the problem to a degree.
Again, I bought the car used, a month ago from a Jaguar dealership. I have no information on mods at this time, sorry...
Vince
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Queen and Country (06-03-2016)
#25
06-01-2016, 05:45 AM
Veteran Member
Originally Posted by ralphwg
Is your XKR stock? When adjusted the HP figures are amazing for a standard XKR, about 548 hp at the crankshaft.
Unfortunately there is no formula to convert rwhp to engine power without putting the engine on a actual engine dyno .
The dyno is simply a tune tuning tool that measures the increase in power after modifications
#26
06-01-2016, 08:22 AM
So you are saying that he may still have just the stock power even though his dyno shows quite a bit more?
#27
06-03-2016, 07:44 AM
Veteran Member
Ralph unfortunately the same vehicle at different shops on different dyno's will yield different rwhp results (some dyno's can be a lot more generous than others) therefore making it virtually impossible to come up with a correct formulae that converts rear wheel hp to crankshaft hp
The correct way a dyno should be used is a pre tune power run then a post power run therefore establishing how much power was actually gained from the selected modifications
The correct way a dyno should be used is a pre tune power run then a post power run therefore establishing how much power was actually gained from the selected modifications
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ralphwg (06-04-2016)
#28
06-03-2016, 10:05 AM
Veteran Member
No symptoms except maybe a stamber or two setting at a red light.
I have had a couple direct cylinder injection motors in the past and this problem has been a Achilles heel to most of the industry.
Pretty sure Jaguar now recommends the cleaning process.
Lexus got around the issue by keeping one injector in the intake runner, so full throttle washed down the valve stems. Audi is dodging law suits for lost HP for similar problems.
If I note any significant change, then I will probably add a water injection system which can mitigate the problem to a degree.
Again, I bought the car used, a month ago from a Jaguar dealership. I have no information on mods at this time, sorry...
Vince
I have had a couple direct cylinder injection motors in the past and this problem has been a Achilles heel to most of the industry.
Pretty sure Jaguar now recommends the cleaning process.
Lexus got around the issue by keeping one injector in the intake runner, so full throttle washed down the valve stems. Audi is dodging law suits for lost HP for similar problems.
If I note any significant change, then I will probably add a water injection system which can mitigate the problem to a degree.
Again, I bought the car used, a month ago from a Jaguar dealership. I have no information on mods at this time, sorry...
Vince
I have heard of a new Nitrogen process.
#29
06-04-2016, 05:02 PM
Senior Member
#31
06-04-2016, 05:23 PM
Veteran Member
#33
06-04-2016, 07:09 PM
Senior Member
#35
06-05-2016, 10:45 AM
Veteran Member
I've built MANY engines with huge torque numbers, mostly for trucks. Well above the HP for each of them, right around the 1000 lb/ft mark. The HP was always near 800.
#36
06-05-2016, 11:05 AM
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Here's a decent article explaining why drivetrain losses are neither a fixed number of HP loss nor a fixed percentage. The losses are actually exponential with power increase.
Drivetrain Power Loss - The 15% "Rule"- Modified Magazine
The article, even more importantly, goes on to explain why chassis dyno results are not comparable to engine dyno results. They're pretty much apples and oranges.
As has been mentioned above, chassis dyno result without a baseline are useless when attempting to measure the effectiveness of modifications.
Drivetrain Power Loss - The 15% "Rule"- Modified Magazine
The article, even more importantly, goes on to explain why chassis dyno results are not comparable to engine dyno results. They're pretty much apples and oranges.
As has been mentioned above, chassis dyno result without a baseline are useless when attempting to measure the effectiveness of modifications.
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ralphwg (06-05-2016)
#37
06-05-2016, 01:53 PM
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ralphwg (06-05-2016)
#38
06-05-2016, 02:03 PM
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Here's the specific paragraph that touches on the concept"
"It's also worth noting that the more powerful you make your engine, the greater the thrust force and angular acceleration it's able to exert on the drivetrain, generating even more friction and heat in the process. But because both steady-state and dynamic friction vary depending on engine speed, engine load and the efficiency of the engine and drivetrain's design (how well they limit friction and the associated thermal conversion of torque to heat), there's no way to apply a universal percent loss to it. Nor is it possible to apply a fixed drivetrain loss figure to your car (say 60 whp from my RevUp G35 example), because as you modify the engine and increase its output its ability to generate thrust force and angular acceleration also increases (though not in a linear fashion)..............
......So rather than attempting to convert your vehicle's dyno-measured wheel horsepower to a SAE net horsepower figure using a percentage or a fixed horsepower value, you're far better off accepting the fact that these two types of horsepower measurements aren't easily correlated and forego any attempt at doing so."
What they're getting at is that horsepower measured while an engine is accelerating (chassis dyno) has a whole different set of dynamics than horsepower measure at steady state (engine dyno). Trying to come up with a formula that allows credible conversion of one to the other is futile.
I'm sure you'll again post 'the don't feed the troll' pic in response.
"It's also worth noting that the more powerful you make your engine, the greater the thrust force and angular acceleration it's able to exert on the drivetrain, generating even more friction and heat in the process. But because both steady-state and dynamic friction vary depending on engine speed, engine load and the efficiency of the engine and drivetrain's design (how well they limit friction and the associated thermal conversion of torque to heat), there's no way to apply a universal percent loss to it. Nor is it possible to apply a fixed drivetrain loss figure to your car (say 60 whp from my RevUp G35 example), because as you modify the engine and increase its output its ability to generate thrust force and angular acceleration also increases (though not in a linear fashion)..............
......So rather than attempting to convert your vehicle's dyno-measured wheel horsepower to a SAE net horsepower figure using a percentage or a fixed horsepower value, you're far better off accepting the fact that these two types of horsepower measurements aren't easily correlated and forego any attempt at doing so."
What they're getting at is that horsepower measured while an engine is accelerating (chassis dyno) has a whole different set of dynamics than horsepower measure at steady state (engine dyno). Trying to come up with a formula that allows credible conversion of one to the other is futile.
I'm sure you'll again post 'the don't feed the troll' pic in response.
Last edited by Mikey; 06-05-2016 at 02:07 PM.
#39
06-05-2016, 03:39 PM
Veteran Member
#40
06-13-2016, 02:20 AM
Remapped? Did it work?
I had a pulley and tune done by ETG last August. After awhile I felt the car didn't feel as aggressive. Maybe I was just getting used to the way it feels so I decided to get it dynoed. Three pulls were done and the second pull yielded the best results. It was 85 degrees today. Uncorrected was 475 hp and 441 torque and corrected was 493.6 hp and 460 torque. I attached the dyno sheets for your review. One is uncorrected and the other has a standard correction. This is rear wheel hp. Does anyone know what the power loss is through the drive train so I can calculate crankshaft HP? Stock was 510 HP so what is it now? I never had a dyno done before so I don't know what numbers are considered good for rear wheel power.
Attachment 130754
Attachment 130754