Compare final drive ratios. I think it's 3.31 vs. 2.51. That'd certainly help from a roll.

 

Based on reports in this thread I am now even more convinced that my engine was suffering from heat soak during the dyno runs.
I can't remember if any fan/s were placed in front of the car during the runs, maybe one medium sized fan, but I distinctly remember that they left the hood/bonnet shut which I thought was more than a little strange.

 

On my way to the dyno. Any guesses on what the results will be?

2017 V6S AWD with VAP crank pulley and tune. Dynojet 424XLC2, temps are mid-80s with moderate humidity. I'll have a 30min drive to get there with minimal time to cool down.

I sent a message to VAP with the tune they sent me asking them to check and confirm it is correct but haven't heard back yet.

 

Hi Guys. I've commented on this in a lot of threads, but dyno runs without before & after data with the same conditions, are not really that useful. I can put the same car on different dynos with the exact same setup and generate different WHP numbers.

I will tell you that particularly when you modify supercharged engines, you'll see heat soak rapidly particularly with dyno conditions (lack of airflow.) We can usually get 2 decent pulls in and the 3rd is starting to pull timing.

If you're not noticing a substantial difference with a pulley & tune, there's something not right with the car, the fuel or other modifications. We frequently see people with aluminum intakes running super lean due to air leaks and pulling tons of timing, for example. If you're not experiencing the performance increase you should, we are happy to review datalogs & vehicle diagnostics with anyone to determine why.

 

First off - I appreciate you responding here.

Completely understood on the before/after and similar conditions point. I never really intended to evaluate the mods on the dyno but just got curious where I'm at relative to stock. The lack of noticing a significant difference has also been stuck in the back of my mind. I'll say that conditions today were definitely not optimal - it was 95 degrees in the dyno bay. We also had some issues getting the car to "be happy" doing pulls and eventually ended up with what we think is a valid pull in 3rd gear at the end ofbthe session. So first question - what gear did you do your dyno runs in for the power/torque chart posted on the product page, and was that an AWD car?

 

That could be a large part of the problem. 3rd gear is way to short gearing to generate enough load to generate boost, and ignition timing. You want to have the vehicle in a gear that is as close to 1:1 as possible. I'd have to check with @Tuning@VelocityAP but I believe you'll want 5th in most JLR. Maybe 6th. Our dyno runs, even on the AWD cars are done with our 2WD dyno with the front drive enabled. Bearing in mind that our Superflow reads low numbers. For example, our XE in 2WD puts down 260WHP from a 340BHP manufacturer calibration when stock. At the end of the day what we are looking for is delta. What % did we gain when we changed something.

The other thing worth noting is - the higher the gear you run the vehicle in, the more power the dyno is going to read. It's one of the reasons you sometimes see dyno charts showed in speed vs. BHP/Torque as well as RPM. So you can clearly show you're running the car in the same gear and not cheating the test by stuffing it in a higher gear for your 'after' runs. So if you ran it in 3rd gear, it's not going to show anywhere near as much power as a proper pull in 5th or 6th.

 

6th is 1:1 and the shop owner discussed it with me but said 6th or even 5th would be a very long pull and not particularly good for the car. I deferred to his judgements and we started in 4th but despite being in Sport mode and manual shifting he said it seemed like the car kept trying to drop into 3rd and we couldn't get a good run. Ultimately we gotta good run in 3rd but never even tried 5th or 6th. Is there some trick.

 

It's a long pull, yes, but we've done 400+ pulls on some of our vehicles and it's required to get proper data. If you were trying to run it in 4th and it's downshifting, it's because there's a kickdown switch under the throttle and you need to go WOT, but not apply enough pressure to hit the kickdown switch.

 

I'd like to log some data just to confirm everything is healthy. I have no other mods - just lower pulley - and I've never noticed anything that would suggest there are issues. Is there a data logging program I can install on my laptop? I'm familiar with the general process - my VW Gti was the development car for a tune. I would do pulls out on the highway and send the log files to the tuning company to revise the tune and repeat.

 

 

Another fan directed at the intercooler radiator would probably help lower the IAT.

 

There wasn't anything remotely useful out there. Just basic Torque App stuff that has horrible latency, doesn't even show you bypass position. So we created our own.

https://www.velocityap.com/product/j...oftware-cable/

 

So.it's $269 if I already have a VAP flasher for my 2017 V6S? Do ypu rent/loan these? Also, do you customize tunes of I send you log files? I'm 100% in for your new ported SC (and probably the new intake ststem as well) but want to be sure I'm getting the most out of everything.

 

The flashing tool, and the cable required for datalogging are not the same thing.

 

Understood. But I'm trying to order it and one of the drop-down options is "I already have a flashing tool". I should use that selection, correct?

 

If you have a Tactrix Cable, or a Mongoose Type Cable, yes. If you only have the VAP flashing tool from your ECU, no.

 

Sorry for the delay on results - I've been on vacation and didn't have a pic of the dyno sheet to post. So here it is - with several important caveats. First, this was 3rd gear. We knew 6th was 1:1 ratio but the shop owner said that would be a very long pull and not particularly good for the car so I deferred to his experience. We tried 4th and couldn't get a good pull - car kept downshifting even in Sport mode. Apparently there is a "kick down" switch under the gas pedal so you need to go full throttle without actually putting it to the floor. Stuart has also stated that we should have done 6th gear regardless of the long pull - lessons learned. By the time we managed to get a decent pull in 3rd gear we had already tried probably 6 -8 times over the course of an hour so heat soak was definitely an issue. We gave it 10-15min rests a couple times but that doesn't afford much time to actually cool down. And finally, it was over 95 degrees in the dyno bay despite having front and back garage doors open. All together I really have no idea how much all of these things added up to in terms of the results. I'm planning to do the new ported SC and associated tuning and hit the dyno again in a couple months when temps are much cooler and knowing how to perform the runs.