VelocityAP Jaguar F-Type ECU Tuning, V6, V6S, V8S, V8R
#301
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2. If it is a damped pulley, I would consider replacing the solid pulley I currently have.
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schraderade (08-20-2016)
#302
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Answers apply to the R only.
1. False, the combination will not overdrive the R1900 beyond Eaton's recommended maximum spin for that SC.
2. True, maximum available upper pulley differential is 8.3%. Maximum lower differential is 11.1 %. And, yes, the lower pulley is much easier to replace and can be removed without destruction. The upper OEM most times cannot be salvaged.
3. When replacing the upper pulley, a smaller belt can be sourced by using a V6 OEM belt. When replacing the lower pulley, only one sided belts come in the right size, so a smooth idler pulley needs to be installed to accommodate. Adds to the materials cost (minor), but the total labor effort (and cost) is much less than swapping out the upper pulley.
4. Traditionally everyone has started by swapping out the upper pulley and that was the only pulley available until early this year. There's only one supplier I know of for the +18mm lower pulley, and VAP is sourcing it from them.
1. False, the combination will not overdrive the R1900 beyond Eaton's recommended maximum spin for that SC.
2. True, maximum available upper pulley differential is 8.3%. Maximum lower differential is 11.1 %. And, yes, the lower pulley is much easier to replace and can be removed without destruction. The upper OEM most times cannot be salvaged.
3. When replacing the upper pulley, a smaller belt can be sourced by using a V6 OEM belt. When replacing the lower pulley, only one sided belts come in the right size, so a smooth idler pulley needs to be installed to accommodate. Adds to the materials cost (minor), but the total labor effort (and cost) is much less than swapping out the upper pulley.
4. Traditionally everyone has started by swapping out the upper pulley and that was the only pulley available until early this year. There's only one supplier I know of for the +18mm lower pulley, and VAP is sourcing it from them.
#303
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I'm not sure about #2...
I'm not sure that Unhingd maxed out all the dimensions...from recollection he's running at about a +15% differential.
#304
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![](https://cimg8.ibsrv.net/gimg/www.jaguarforums.com-vbulletin/1207x564/pulley_ratios_1_7b9b347fa4510fe0b5b7c75d1702354565b6bf19.jpg)
Thanks...I've passed #1 onto Stuart at VAP.
I'm not sure about #2...
If the lower pulley is increased by 11% and the upper pulley reduced by 8.3%, then the supercharger turns (1+11%) / (1-8.3%) = 21.0% faster.
I'm not sure that Unhingd maxed out all the dimensions...from recollection he's running at about a +15% differential.
I'm not sure about #2...
If the lower pulley is increased by 11% and the upper pulley reduced by 8.3%, then the supercharger turns (1+11%) / (1-8.3%) = 21.0% faster.
I'm not sure that Unhingd maxed out all the dimensions...from recollection he's running at about a +15% differential.
#306
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I have just flashed a tune from the kind folks at VelocityAP. I have so far only driven to the store and back, but should have better observations in a day or two. Initial impressions are that it is more responsive in the lower midrange in the first third of the pedal travel. I'll need some miles before I'm sure, but I think the lag I've noticed from the start is gone. It always seemed that there was a delay between putting my foot into it and the engine figuring out what I wanted.
#307
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I have just flashed a tune from the kind folks at VelocityAP. I have so far only driven to the store and back, but should have better observations in a day or two. Initial impressions are that it is more responsive in the lower midrange in the first third of the pedal travel. I'll need some miles before I'm sure, but I think the lag I've noticed from the start is gone. It always seemed that there was a delay between putting my foot into it and the engine figuring out what I wanted.
#308
#310
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slipstream (04-10-2020)
#311
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Won't be feeling much today (other than wheelspin). Rain has moved in. Not that I am not happy about that, but real driving impressions will be a few days off at least. Even if it's dry tomorrow I'll be working from home while waiting for the mobile glass company to come and replace my windshield.
#312
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Nothing but commuting since the tune, but I do have a few impressions now. No dyno readings, no lap times, no ETs. I'll need to fill up tomorrow, so will have a first fuel economy reading then.
The purely subjective short term report:
- stronger midrange
- revs more quickly
- pulls more cleanly to redline
- increased sensitivity/response in first 1/4 of pedal travel
- previous lag between pressing accelerator and engine response is greatly reduced
That last one needs a little more explanation. I've mentioned it before, but there is an inherent lag in the system. Perhaps it's more noticeable on the manual transmission, but the feeling I've had is that the engine delivers power mildly until it passes a threshold, then goes to more aggressive acceleration. That threshold seems to be a combination of pedal position and RPM, and the transition is as noticeable a the change when turbocharged engine "spools up." I still feel the transition, but it comes sooner (lower RPM and less throttle) so is not as abrupt. I don't feel like I need to gas it to get past the transition, then back off to the power I really want.
Surprisingly, at light cruise it seems smoother too.
The purely subjective short term report:
- stronger midrange
- revs more quickly
- pulls more cleanly to redline
- increased sensitivity/response in first 1/4 of pedal travel
- previous lag between pressing accelerator and engine response is greatly reduced
That last one needs a little more explanation. I've mentioned it before, but there is an inherent lag in the system. Perhaps it's more noticeable on the manual transmission, but the feeling I've had is that the engine delivers power mildly until it passes a threshold, then goes to more aggressive acceleration. That threshold seems to be a combination of pedal position and RPM, and the transition is as noticeable a the change when turbocharged engine "spools up." I still feel the transition, but it comes sooner (lower RPM and less throttle) so is not as abrupt. I don't feel like I need to gas it to get past the transition, then back off to the power I really want.
Surprisingly, at light cruise it seems smoother too.
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zmoothg (11-08-2016)
#313
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First fuel economy rating: 17.9 mpg. My 10K mile average is 18.7 so that's certainly in the ballpark. Once I settle down and start driving with a modicum of sanity (translation, like slightly less of an idiot) it might even show better than my running average. Commutes where I spend time literally idling in first gear do not help in any case, and I've had a bit of that.
#314
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First fuel economy rating: 17.9 mpg. My 10K mile average is 18.7 so that's certainly in the ballpark. Once I settle down and start driving with a modicum of sanity (translation, like slightly less of an idiot) it might even show better than my running average. Commutes where I spend time literally idling in first gear do not help in any case, and I've had a bit of that.
#315
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I use it every day, but not all the time. For stop and go traffic on the freeway I turn it off, but elsewhere I keep it on.
#316
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Just installed the Stage 1 Tune for my MY16 AWD R. Will be doing the Stage 2 once I get the Pulley installed next week. Initial impressions.
- The midrange has come alive
- A slight increase in gas mileage
- Exhaust: The exhaust pops and crackles are more tame now, before I could have the car in 2 gear and accelerator to 3000RPM, let off and the fireworks would go off, with the Stage 1 tune this doesn't happen as easily if at all. I still get the farting in 1st gear, I'll have to play with this more tomorrow. On the other side, the note feels a bit more deeper/throaty now.
- The acceleration is ALOT smoother than stock tune. The car pulls like butter, especially when in dynamic
- The cars revs a lot quicker
- The pedal lag is gone, when you tap the pedal now there is an instant response from the car, and getting to speed feels effortless. (Something you need climbing San Francisco hills)
Overall, I am quite pleased with the results thus far. I will have to play around with the exhaust sounds tomorrow, to confirm that I have lost some of the crackle & pops from the tune.
- The midrange has come alive
- A slight increase in gas mileage
- Exhaust: The exhaust pops and crackles are more tame now, before I could have the car in 2 gear and accelerator to 3000RPM, let off and the fireworks would go off, with the Stage 1 tune this doesn't happen as easily if at all. I still get the farting in 1st gear, I'll have to play with this more tomorrow. On the other side, the note feels a bit more deeper/throaty now.
- The acceleration is ALOT smoother than stock tune. The car pulls like butter, especially when in dynamic
- The cars revs a lot quicker
- The pedal lag is gone, when you tap the pedal now there is an instant response from the car, and getting to speed feels effortless. (Something you need climbing San Francisco hills)
Overall, I am quite pleased with the results thus far. I will have to play around with the exhaust sounds tomorrow, to confirm that I have lost some of the crackle & pops from the tune.
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slipstream (04-10-2020)
#317
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Pedal commander would deal with that for those w/o a tune or maybe as a supplement to a tune.
- previous lag between pressing accelerator and engine response is greatly reduced
That last one needs a little more explanation. I've mentioned it before, but there is an inherent lag in the system. Perhaps it's more noticeable on the manual transmission, but the feeling I've had is that the engine delivers power mildly until it passes a threshold, then goes to more aggressive acceleration. That threshold seems to be a combination of pedal position and RPM, and the transition is as noticeable a the change when turbocharged engine "spools up." I still feel the transition, but it comes sooner (lower RPM and less throttle) so is not as abrupt. I don't feel like I need to gas it to get past the transition, then back off to the power I really want.
Surprisingly, at light cruise it seems smoother too.
That last one needs a little more explanation. I've mentioned it before, but there is an inherent lag in the system. Perhaps it's more noticeable on the manual transmission, but the feeling I've had is that the engine delivers power mildly until it passes a threshold, then goes to more aggressive acceleration. That threshold seems to be a combination of pedal position and RPM, and the transition is as noticeable a the change when turbocharged engine "spools up." I still feel the transition, but it comes sooner (lower RPM and less throttle) so is not as abrupt. I don't feel like I need to gas it to get past the transition, then back off to the power I really want.
Surprisingly, at light cruise it seems smoother too.
#318
![Default](/forum/images/icons/icon1.gif)
Just installed the Stage 1 Tune for my MY16 AWD R. Will be doing the Stage 2 once I get the Pulley installed next week. Initial impressions.
- The midrange has come alive
- A slight increase in gas mileage
- Exhaust: The exhaust pops and crackles are more tame now, before I could have the car in 2 gear and accelerator to 3000RPM, let off and the fireworks would go off, with the Stage 1 tune this doesn't happen as easily if at all. I still get the farting in 1st gear, I'll have to play with this more tomorrow. On the other side, the note feels a bit more deeper/throaty now.
- The acceleration is ALOT smoother than stock tune. The car pulls like butter, especially when in dynamic
- The cars revs a lot quicker
- The pedal lag is gone, when you tap the pedal now there is an instant response from the car, and getting to speed feels effortless. (Something you need climbing San Francisco hills)
Overall, I am quite pleased with the results thus far. I will have to play around with the exhaust sounds tomorrow, to confirm that I have lost some of the crackle & pops from the tune.
- The midrange has come alive
- A slight increase in gas mileage
- Exhaust: The exhaust pops and crackles are more tame now, before I could have the car in 2 gear and accelerator to 3000RPM, let off and the fireworks would go off, with the Stage 1 tune this doesn't happen as easily if at all. I still get the farting in 1st gear, I'll have to play with this more tomorrow. On the other side, the note feels a bit more deeper/throaty now.
- The acceleration is ALOT smoother than stock tune. The car pulls like butter, especially when in dynamic
- The cars revs a lot quicker
- The pedal lag is gone, when you tap the pedal now there is an instant response from the car, and getting to speed feels effortless. (Something you need climbing San Francisco hills)
Overall, I am quite pleased with the results thus far. I will have to play around with the exhaust sounds tomorrow, to confirm that I have lost some of the crackle & pops from the tune.
Lawrence