I just had Specialty Z install my 2.85" supercharger pulley. My old numbers with the 9lb pulley were 541whp 440 torque @ 10 psi. My new numbers with the 2.85 pulley addition are 586whp 486 torque @ 12.86 psi.
https://www.instagram.com/p/BkMC8SyF...=1v0kruqzp88uj

Wow is that just with Si impeller or did you change the jackshaft as well?

This is awesome. Nearing 600whp and 500wtq on the upgraded kit!!

2 years ago if someone told you they made that power out of a centri blower on the 370z you would have been laughed at and ridiculed as being a liar.

Winning! :happydance:

That car must be an animal

Jackshaft is stock. If I was strictly running e85 I would have had the 3.47 jackshaft installed but I'm on flex fuel (91 octane). Seb had to dial back the timing on 91 as it is on 12.86 boost.

I love the way it makes power. The extra 45ft.lbs. made the difference.
If you look at the dyno sheet, the power drops completely off at about 6900rpm. I asked Seb about that and he said the throttle is staying open to redline but boost is dropping off. He thinks the air filter is restricting the air flow to the sc. Beyond installing the turbo guard screen is there anything that can be done to get more air flow? I'm assuming the stock stillen boot and filter more restrictive than the filter that's on it?

I would spray some CRC dressing on the serp belt and data log the boost for a few street pulls. Then spray the SC belt and data log. That way you can determine where the slip comes into affect. I dont think its the filter as there is no reason it would just choke out and stop breathing completely like in the chart. It would be gradual and hold more of a straight line than a plunge.

Seb didn't think it was belt slip but like he said, he's on a learning curve with superchargers. I have the tbatt upgrade, do you think I could still be getting belt slip on the serpentine side? I guess most likely it's would be on the sc side. I had the same issue on my first tune with him too, prior to installing the 2.85 pulley. I'll talk to Seb about doing some data log runs with the belt dressing on each side. Thanks for the insight.

I've put belt dressing on both sides of both new belts and I have the TBatt pulley and the Si impeller and the 9lb pulley. I only make 8.5spsi @ 7k RPM on the street (3rd gear pulls)... Seb made almost 10psi on the stock 8lb pulley on someone else's car on a dyno (generally done in 5th gear).

I don't say that to knock anybody or anything, but to give you a data point if your street data looks different from your dyno data.

I haven't been able to get on a dyno yet to see pressure there since I went to the 9lb pulley.

The thing I have yet to do is use a thermal imager on the pulleys to see if any of them are heating up more than the others because of the frictional heat from belt slip (if that is the issue).

If you have any questions with what I've done to ensure that the issue is not with the engine, I'll be happy to talk to you about it. I can also trade logs with you if you'd like just for comparison to see if we're seeing proportional and similar performance.

Out of curiosity, if you don't mind, do you have the 928 bearings?

I called Vortech and the tech guy said most likely belt slippage and if I have slippage there should be belt dust and suggests high traction pulleys.

I checked and I have a lot of belt dust below/around the jackshaft pulley in the sc side so I'm definitely getting belt slippage. There is no belt dust around the sc pulley but the 2.85 I bought is a high traction. No belt dust anywhere on the serpentine side. I went ahead and ordered the high traction jackshaft pulley. Wondering if I should go ahead and change the sc belt also?

I don't have the 928 bearings and I know the bearings could be living on borrowed time.

Also, all of my logs were done on the dyno in SZ shop. I haven't done any data logging on the street. I made a little over 10psi with Si sc and 9lb pulley on the dyno.

This is all good info. Is anyone here running more than 1 breather filter on their PCV/crankcase vent hose? We ran into issues after tuning closed loop then going to open loop so I had to take it apart and look. Found that my 5/8 hose leading to crankcase vent was kinked trying to make the bend, so I put in a 3/4” brass elbow. Also cleaned and calibrated my wideband O2 (not yet wired to ecu) and downstreamo2 but don’t think that’s causing the issue.
Seb sent me this
“Since you have breather filters on the larger 5\8 VC ports I suggest you put the PCVs on breather filters as well. One thing that occurs is since you have breather filters on the larger ports you've essentially created a vac leak with the intake manifold going to the PCVs.“
Any idea where he’s thinking? The only place i can think is putting another T and a filter right at the PCV valve.

Here's how Seb did mine. Pic is drivers side. Passenger side has hose running from pcv to rear of engine compartment and filter installed on end of hose. Couldn't get pic of that.

Thanks that’s really helpful I think I get what you’re saying. So look at the pic of my breather filter and you can see that hose just next to it on the upper left with the blue octagon, he deleted that hose and just put a filter there? And my other pic there is a T joint (where that same hose splits off to the blue octagon port), instead of that T joint he just capped that part of the hose with filter also?
Thanks for the help a big reason i wanted to do this was to learn my engine bay, and imma learn today!

First pic is correct. Second pic, he deleted the tee completely and ran a hose off the pcv valve to the rear of the engine bay and installed a filter on the end of the hose.

And when I was looking at mine I noticed the passenger side has a kink in it right after it exits the pcv valve.

So with the a2a kit, I understand that the PCV is removed. This means the combustion vapor (water/fuel) other stuff will stay in the engine and cause more sludge/deposits.
The PCV system ventilates the crankcase.

Could this be a possible negative effect in the long run for the engine, or am I understanding something wrong?

Anyone can shed some light on this?

No, its vented to atmosphere

I was able to disconnect my passenger side pcv hose and re-route it. No more kink.

Isn’t the 2.85” the 9lb pulley? Wasn’t your old pulley the 8lb? Crazy numbers you’re making me want to say hold the phone and throw on the 2.85” but wanna make sure everything is kosher first. Tuning for flex but I plan to run e85 90% of the time but i guess it’s that other 10% things get dangerous

The 9lb pulley goes on the jackshft on the serpentine side. The stock serpentine jackshaft pulley is 8lb. The 2.85 is installed on the supercharger.

I'm running flex. Same thing, e85 90% of the time. The only time I'll be on 91 octane is if I take a trip and e85 isn't available. Seb pulled a bunch of timing on my 91 tune (for safety) and and primarily set me up to make all my power on e85.

Can you guys give the part numbers or link for the pulleys that you picked up from Vortech? Or let me know how you communicated your needs to Vortech. I want to change up my pulleys now for the high traction design given my lower-than-expected boost issue to see if that might help. The CRC dressing got me .3 more psi haha

I saw this one, Part# 2A038, on the Vortech website. It is the same part number for the "normal" 8-rib supercharger drive pulley and the "high-traction" pulleys...

The high traction category doesn't have a 3.4 option... Otherwise, I'd go back to the 8lb serp side and do the 3.4-3.0 jackshaft-SC on the SC side like Topz

I was thinking of keeping the 9lb serp side and ordering two 3.15 (is this what y'all are calling the 3.2?) high traction to replace the SC side.

And to answer the question, you might as well replace the belt, knowing that you've worn the belt a bit and having everything apart.

I'm replacing my jackshaft pulley with the 2A038 high traction 3.15 as they don't make a 3.20. I don't know what manufacturer the stock jackshaft pulley is but it's not a Vortech. Also, if you change your jackshaft pulley to the Vortech, you need to add a spacer to the sc shaft as the Vortech pulley is a different offset than the stock 3.20. 928 Motorsports makes a high traction 3.25 that looks pretty interesting but it's $180.00.

I already have a new belt ordered.

If I get a pair and replace both the jackshaft and the SC pulleys with the 3.15 (or smaller) High Traction from Vortech, won't the offsets match?

Nope. I installed a Vortech 2.85 sc pulley and it lines up fine with the stock jackshaft pulley. When I change my jackshaft to the high traction Vortech I'll have to add the spacer. FYI, 928 Motorsports carries the spacer, it may need to cut to length. Also, you'll have to use a longer bolt on the Vortech jackshaft pulley as it's wider than the stock pulley.

Stillen didn't use a Vortech pulley for the jackshaft, it looks like a Magnuson but I'm not positive.

Interesting...

Thanks for the info!!!

I'm not sure my tranny is ready for that much boost haha. Or me ready to spin the Vortech bearings that fast haha. But since I'm swapping out the pulleys anyways, I might go with the 3.15 jackshaft and maybe the 3.0 SC...

Per the Vortech calculator, I'm at 55.6k RPM now (with the serp-side 9lb pulley). Bumping down to the 3.0 while keeping the 3.15 ~stock size jackshaft would put me at ~58.4. Strongly debating stepping down the size since it'll keep me in the limits of the tranny.

If I had the 928 Supervortech upgrade, I'd go 3.47 jackshaft and 2.85 SC, which would spin it ~68k!

Did you just source the longer bolt from Lowe's or similar? Did you increase the SC-side idler?

Thanks again!!

I know I'm over spinning the Vortech bearings, I'll see how long they last. I might buy a spare V3 Si and send it to 928 for the bearing upgrade just in case.

I haven't gotten the bolt yet, my pulley won't ship from Vortech until next week. I have the 3" idler pulley installed.

I went ahead and picked up some high traction pulleys today. Where did you guys get the 3" smooth idler from for the SC side or what did y'all do instead? I thought someone just custom fit a nut in there or something that allowed the stock idler to move up further.

Thanks!

I think I saw a post where someone did do the "nut" thing but why not spend $25.00 and get the Gates #36225 idler pulley.

If you are going with the A2A upgrade from a stock Stillen kit and go the 9psi route you will need my kit to prevent belt slippage. You will be driving the supercharger with about 60 hp and the belt will slip. Some have been slipping at 8 psi.

The stock Nissan belt tensioner will take up the slack of going to a smaller jackshaft pulley (Stillen 9psi) but the contact area of the drive belt goes down and that will cause slip, Add in the extra load on the belt to drive the SC faster and more slip.

To try and keep things simple, the serpentine belt is the main drive belt and is a long 7 rib belt that connects the crankshaft pulley to all of the other main drive pulleys (including the supercharger jackshaft).

The other belt is the supercharger drive belt (small 8 rib belt) that connects the jackshaft to the supercharger. You can get to 9psi by replacing the SC pulley with a 2.95 inch pulley from Vortech (part number 2A038-295). If you go that route the drive belt tensioner will not have enough adjustment range to take up the belt slack due to the SC having a smaller diameter pulley. To fix that you will need to replace the idler pulley on the SC drive with a 76mm (Gates 36225).

I'm running the 2.95 Vortech pulley along with my extra idler pulley setup and am getting close to 9.5 psi. YMMV

Great info being passed along here. Thanks guys.

Speaking of your kit. Thought I'd share what I found recently. Don't know if you recall but I mentioned that I had an unusual loud whining noise after switching to your kit. Turns out some parts of the belt had sections of the sepertine teeth missing.

I ended up checking all idlers, 2 of them had bad bearings, 1 was atrocious and probably the reason for the noise (it was the smooth idler, not the 2 grooved ones). Could this have caused the damage with my belt or did the belt make the bearings worse?

Also, since as of tomorrow I'm a Boosted Performance Snail member, the SC kit is for sale, but I'd like to replace the belt for the unknown buyer. What is the belt model?


Cheers,

Sorry you are having a problem.

Your serpentine belt is badly damaged! Do not run it like that.

All belts that I deliver are modified by cutting off one of the ribs converting an 8 rib belt to a 7 rib belt. This modification is done using custom tooling and every inch of the belt is inspected before I modify them.

It looks like you had a idler pulley bearing failure that in turn damaged the belt.

The SC belt is a K080220 from MAGNUSON SUPERCHARGERS GATES MIRCO-V AUX BELT REAR 8-RIB Gates K080220 [M-79-08-02-020] - $42.00

If you need another serpentine belt to replace the damaged one, PM me.

Speaking of idler pulley bearing failure. The Stillen idler pulley, serpentine side on mine has a slight wobble and if you listen to it with a stethoscope, it's a lot louder than all the others.

Thanks mate!

PM incoming.

I recently added a filter to my bpv, here's what it looks like now.

That's odd. I used this cheap thing for over a year back when I had my SC. Never an issue. :confused:

Daaaaam that thing looks best to $#!t

The plastic couldn't take the heat. The one that did is steel.

Yeah, I didn't think about that. I wondered why it only quieted down for a few days. :tup:

I noticed that the tial is open at idle and low rpms. Is that normal?

Yup. At idle your supercharger is still spinning. Where will the air go when your throttle bodies are shut?

https://imgur.com/a/4K0M2Mt

just wanted to share, the kit bolted up to a VQ35HR relatively easy. Minor cutting and massaging had to me done to make it all fit. Waiting on a tune to get everything going.