Am I correct in seeing this as a new upgrade for the V6 cars from VAP? I seem to recall that the prevailing wisdom was that the upper pulley could not get smaller on a V6 car, but I am now seeing it as an option over at VAP. Appreciate any detail on gains, etc.

 

Nope...They have had the V6 Upper Pulley for some time.

DC

 

Thanks! Any idea how much additional boost/hp with the upper? I don't see it on the VAP site

 

Don't recall exactly, but I think it was about 1.5 PSI for the V8? The V6 is already pretty small, so likely less.You can do the upper pulley without getting a tune and get a slight boost increase. You typically will need a tune with the lower pulley (or both). On the V8, I think the lower pulley is ~11.5% increase in size.

DC

 

Thanks- yes I have the lower and tune (plus transmission tune) already. I live at 4800 feet with regular trips as high as 10,000 feet. We like the boost up here!

 

You need a 2-speed supercharger like the Rolls Royce Merlin had, for high-altitude power.

 

Haha...How can anyone NOT like boost. Its like the Bacon of cars...Everything is better with bacon...

On a more serious note...If you have the TCU/ECU tune, and lower pulley, I doubt you will get much(only marginal) by adding the upper pulley, given the work required to press off and on...You are now at the point of diminishing returns for sure...But it is your car, so enjoy and do what you like.

DC

 

Last time I checked, VAPs supercharger pulley is the same diameter as the stock v6 pulley (62 mm). However, it comes with a coating for better grip

 

Just got the email, it says it is 58mm

 

With the belt routing JLR designed, a smaller upper pulley for a V6 (62mm upper) was not really worth doing due to belt slip. Our new Griptech coated 2-piece design makes it feasible.

 

We've had one for the V8, but it's a stock upper size for the V6.

 

We saw just a little over 2psi.

 

Hey Stuart

Sounds like there’s some confusion as to what changed regarding the details around any benefit for a smaller SC pulley on the V6 pre/post your recent GripTec advancement.

As I understand it, prior to GripTec technology a smaller pulley on the SC had some slippage at the higher RPM which negates any real benefit. But with the GripTec advancement, you’ve eliminated that and we’re able to see an additional 2 psi of boost.

The increase in RPM on the SC is slightly above the manufacturer’s specs but it sounds like the manufacturer understated it’s true tolerance… similar to our engine’s redline (6500 vs. 7000 with your ECU/TCU tune). So no issue with the increase but as with all mods, it’s also based on how hard you drive and push the limits of your car.

And you’re also saying (in other posts) that with the increase in boost, it’s critical to have high quality fuel to prevent knocking but otherwise it’s a safe and a way to get an additional 20 HP on top of the crank pulley/ECU tune.

 

This question is more up my alley, I’ll tackle it on behalf of Stuart…

The confusion of “no benefit” would be fitting the pulley we designed for the 5.0 to fit on a 3.0. The stock 5.0 comes with a 65mm and we had offered a 62.7mm pulley. However, the 3.0 comes stock with a “63mm”..so fitting our 5.0L pulley to a 3.0 only sees a reduction in size of 0.3mm…aka “no benefits”.

Until recently, we never offered anything smaller than 62.7mm. With our recent addition of the 58.5mm, this fits in the snout with no interference on ONLY the 3.0 and provided a performance benefit(unlike fitting a 62.7mm to the 3.0..etc). No testing has been done yet on the 5.0L with the 58.5mm, simply because the snout needs to be shaved down, that’s a project for another date.

All of our SC pulleys are now coated with the Griptec coating AND are now all the 2-piece design. At the time of writing this, we offer a 58.5mm for the 3.0 and 62.7mm for the 5.0.

In response to the supercharger manufacture(Eaton) rated max efficiency speed, the TVS1320 which is on the 3.0L(AJ126), is set at 20,000rpm(Eaton spec). If fitting our VAP crank pulley and our newly released VAP SC Griptec coated 58.5mm, the blower would achieve 19,666rpm at 6500rpm engine speed. With a TCU tune at 7k engine speed, the blower would be seeing 21,179rpm. Nonetheless, above 20k blower speed does not mean it’s worthless, it just means the efficiency drops off unless more cooling is achieved over factory to avoid heat soak. On side note; The Audi 3.0TFSI platforms running this similar TVS1320, the sweet spot has been found at 24,000rpm…well above the 21,179rpm that we can spin with our pulley ratios.

 

Thank you for the detail on the V6 SC pulley and the specs on the TVS1320. That gives me considerable reassurance that this set up is within reason and the component’s tolerance.

Regarding previous V6 SC pulley, I think the data and results were based on the Eurotoys and Mina Gallery SC Pulley that yielded the “no benefit” comment. I don’t think think people were referring to VAP or your products in this instance. With the Eurotoys and MG SC pulley they stated it was either not necessary or had very little change.

Thanks again for those details and I hope this pulley sells well. I’m certainly going to pick one up and get a new tune for it. Looking forward to stepping up my car one more notch.

 

don't waste your time with the upper pulley

 

Your video link only confirmed a 2.8in pulley has a smaller circumstance than a 3.8in pulley. Please do elaborate more to justify your statement..

I have countless datalogs showing how the 58.5mm Griptec coated pulley slips less than the stock 63mm pulley.

 

How many times are you going to post this same video? You getting a commission or something? Every time there is a thread about anything, where the word belt - or pulley is mentioned - BAM...You post this same video.

Get some new material...

I have seen this bald dude so much now, I feel like I should invite him over for Christmas dinner.

 

First time I've watched the video and thanks for sharing but if you went through this thread, you'd see that VAP come up with their GripTec design to address this slippage issue. Given VAP's overall reputation, other forum member's positive experience and my own personal experience, I trust Stuart, Chris and VAP's claims on their new SC pulley. I doubt they'd risk their outstanding reputation to sell a faulty $319 item.

 

Hi Dennis,

The point that the gentleman in the video is making that is valid is - there are less problems with slippage if you upsize the crank pulley versus downsizing the supercharger pulley. As a general rule that's not wrong. It's particularly important on the JLR supercharged engines because the tensioner design doesn't allow much wrap on the upper pulley anyway. (It's also one of the reasons the belt needs to fit snug.) However, our Griptec pulley doesn't have any problems with slippage as we've verified through datalogging. This would not be the case with a standard steel or aluminum pulley without the coating.