Hey guys, this is just a wild thought at this point, but out of curiosity, do any Vortech owners have experience with a machined 2.62" pulley - like the one GTM makes?

http://gtmotorsports.com/product.php?productid=16472

The standard 2.62" pulley has been discussed a few times on my350z, looks like the general consensus was that *if* you could eliminate the belt slippage, it still may produce too much boost or wear down the head unit from overspinning.

I'm trying to think of a specific setup where this could work safely: machined 2.62, GTM pulley mod (extra tensioner pulley, shorter belt, completely solves the slipping problem w/2.87's), a conservative tune (probably the stock non-revup redline, slightly retarded timing on the top end), and possibly even the adapted wastegate idea discussed before, to limit boost to 13-14 psi.

If I'm currently hitting 403 whp @ 6800 RPM, I'm thinking it wouldn't be too difficult to hit ~420 whp @ 6600 RPM with this setup. But what would really be nice would be the quicker onset of boost, a little more thrust in the midrange (that was my favorite part of changing from the 3.12 to 2.87).

It's all just speculation at this point, just curious what your thoughts are on this.

 

u willing to risk blowing up your motor for 20 more hp? If u arent going to build your internals dont even think about getting the smaller pulley. I would rather invest on a good true exhaust system first and save up for internals. I wouldnt push it more than 400hp on a stock block. I was at 433 and it didnt last long until it blew and I only had 21,000 miles.

 

433 supercharged!? Wow, I can see it going kaboom at 450, 433 is kind of surprising. But that's what's weird about my idea, I'm not really looking for much on the top end, if I had to, I'd be willing to limit boost to 13 psi (which I was running before I opened up the exhaust with my fujitsubo). It's the shift in the onset of boost that's so appealing.

The other thing I've been thinking about long term is an Si-trim upgrade with eagle rods. But then I'll worry about the cog pulleys eating themselves, like some of the z drivers have experienced.

Just seems like any way you go with an SC, beyond 400 whp you've got a belt-driven machine spinning so fast, there's a huge risk of something catastrophically failing.

 

your best bet is to upgrade the blower if u want boost to come in faster. I can get 1 psi by 2500 rpm with the T trim or u can just upgrade tot he SC trim and should produce the same end hp but not as big top end gains as the t trim.

 

I've been running just under 400 on a stock block- greddy twin for over a year now.

41,000 miles.. I invested in a great ECU and a good tune.

Works just fine.

 

Under 400 is fine. I'm just stating pushing it over 400whp will not last long if u are on stock block. I have seen stock blocks with VPRO and still blow bc they were over 400hp. The only stock block able to push a little over 400 are the revup motors. There havent been any posts or reports of internals failing if they stay below 420whp. But if u do push it over 400whp, I would not rev it past 6400 rpm (on the higher gears) to be on the safe side.

 

I've always been under the impression that the 400 whp rule has some catches too, since the curves are so dramatically different between SCs and turbos. I could be wrong, but I remember reading that some of the Z guys have been pushing up to 440-450 whp with SCs with relatively few problems, if they don't drive it like they stole it.

I think if (big IF) I were to do this, I'd find out exactly how much boost I'm pushing right now with the 2.87, then use a wastegate to limit output from the 2.62 to something very close to that (as close as we can get). And the end result would be more area under the curve, shifting the onset of boost slightly left.

 

if u cant drive it like u stole it then there's no fun. I rather have a car pushing at 400hp where I can push the gears to the limit than a 440whp where I cant go past 6K rpm or something might break.

 

That's exactly what I'm saying, I'd limit boost to my current output, putting me somewhere around 400 whp, but I'd have more kick in the midrange. So I could still drive it like I stole it.

 

This conversation is so pointless because there is no safe horsepower- you can't safely boost your car- you can not be stupid about it.

lock the thread- if you're worried about blowing it- build it.

 

i would just add some nitrous onto the car, it will give you that instant power you are wanting. we can ship out all the parts you would need or you could just ship us the car and let us build it for you...

 

This coming from a guy running twins on a stock block, pushing what, 8 psi?
Who the hell are you, passive aggressively calling me an idiot? As fas as I can tell, NO ONE is running a 2.62" pulley. I had a THOUGHT, I posted in an attempt to engage people and see if the idea is viable with newer tools, aka GTM pulley mod, and a wastegate on a SC setup. And I get this in response.

Let's say I'm running exactly 12.0 psi of boost right now (MAX, with a supercharger, aka NOT across the RPM band, need I spell it out further, or can you read?), I throw on a machined 2.62 pulley and a 12 psi wastegate, we torture test it, it maxes out at 12 psi. You're telling me that idea is stupid, the motor is guaranteed to explode, pointless post, waste of space? If you don't have something constructive to add to a decent idea, simple, keep your mouth shut.

Don't get me wrong, I like a lot of you guys, you're extremely helpful and you have a lot of experience to share. But I'm sorry, some of you are just a nice little combination of four letter words.

P.S. I swear to God some of you guys don't even read posts. Quote from the first post of the thread:

"Hey guys, this is just a wild thought at this point..."

But you interpret it as something that's planned, paid for, and scheduled?

 

Thanks man, I think I'm gonna stay off the juice though (personal qualms). By the way, the helpful/experienced/engaging people I mentioned, you're the perfect example!

 

That's fine you obviousy don't read my posts either.

A. I'm running 10psi on a stock block
B. I have the money to rebuild my motor if I bend a rod
C. I would have never boosted my car if I was concerned with blowing my motor- it took a while. I'm just dont understand the point of finding that edge of the stock motor and keeping it there.

I'm really hurt that "Aero" doesn't find my posts "helpful,experienced or engaging"

My point is that extra 20 hp on your stock block is pointless. And I think your going to blow your motor.

Once again- If you're worried about blowing it- it's time to build it.

 

And I would actually agree with you on this, if it were my goal. If all I wanted was a little more on the top end, I'd throw on some headers and call it a day. But what I really find interesting is the possibility of quicker boost with a rarely used product (that hasn't been discussed more than two or three times). And instead of getting engineering-oriented responses, I hear a parrot saying "you can't break 400 whp, you can't break 400 whp". Well, that may be completely irrelevant, if you limit maximum boost, the only risks you run are additional blower wear and a very small risk to the motor because 1 psi comes on 500 RPM sooner.

It doesn't help me, and it doesn't help anyone else who may one day do a search for "2.62 pulley" and pull up this babbling p!ssing contest.

And don't you worry man, should my motor blow, it won't be a financial problem. There's a big difference between trying to avoid paying $5K for damage and dishing it out because you have no choice.