So it's time for a smaller pulley.

**Booba5185** · 02-06-2015

I believe it's basically the same thing at that point, except the Gen V rotors have a better teflon coating on them. I doubt that makes much of a difference though. Your FSIC is really what's letting you run that 3.0, IMO but I'll be the first to say I'm no expert...I started this thread, lol. If I'm going to sink FSIC type of money into the car, I'm just gonna save up more and stuff a snail in there.

**99GT2dr** · 02-06-2015

Maybe I'm not understanding this, haven't really looked much into the Gen V. When they first came out it was well over a grand to get hold of one, and I never even considered it because of that. I keep hearing it's a more efficient blower, which to me would mean cooler outlet temps than the Gen III. So a 3.5 on the V would be nothing at all like like a 3.3 on a Gen III, which would have far higher outlet temps. It's an M90, so it's still only moving 90 ci of air per revolution, the V is just doing it keeping outlet temps lower, which should decrease KR everything else being equal. Unless I'm missing something, I don't see how a larger pulley on a more efficient blower is comparable to a smaller pulley on a less efficient one.

**Booba5185** · 02-06-2015

http://www.grandprixforums.net/threa...-five-gen-5%29
From Eaton:

The 90-cubic inch Gen Vsupercharger is very compact. Its housing includes the throttle-body adaptor, crankcase ventilation plumbing,
coolant passages, the evaporative emissions purge valve and the rotor
drive mechanism. The drive mechanism is sealed and permanently
lubricated, obviating the need for oil connections and eliminating a
potential source of leaks. Moreover, the Gen Vfeatures all-cast
components and a larger, low-restriction outlet port. The tuned inlet
port is also less restrictive, compared to previous-generation
superchargers, allowing a larger (75 millimeter) throttle body. As a
result, more air is pumped by the supercharger through the Series III’s
induction system. The Gen V’s rotor is finished with Abraidbable Powder
Coating (APC) rather than epoxy. APC is a patented material containing
graphite that is electrostatically applied to the rotor and baked on. As
a result, the rotor requires less clearance within the supercharger
housing, resulting in less leakage around its edges, greater airflow at
a given operating speed and lower operating temperature. The Gen V’s
rotor bearings have been enlarged to increase durability and reduce
operating noise and vibration.

As a result, the Gen Voperates at considerably higher efficiency than
its predecessors. At wide open throttle, the Gen Vturns at 700 fewer
rpm (a 9 percent reduction), draws 13 percent less power from the
crankshaft, decreases operating temperature 15 percent and increases
volumetric efficiency 9 percent. For the customer, that means a 9
percent increase in horsepower (see product specifications), and best-
in-class acceleration times for the Grand Prix.

**99GT2dr** · 02-06-2015

So if I'm reading that correctly, the Gen V turns 9% slower, uses 13% less power to spin, and outlet temps are 15% lower than the Gen III comparing them with same size pullies. With the VE being increased 9% as well, I could see you needing some more fuel compared to the same size pulley on a Gen III, but otherwise the cooler outlet temps and the fact it's spinning 9% slower should help to decrease heat and therefore KR.

Running a 3.3 on a Gen III should certainly cause more KR than a 3.5 on a Gen V, the percentages above I'm sure were all assuming stock pullies, the gap between them should increase as you pulley down. Now if you're running the same tune for both blowers, I could see the Gen V running you leaner since its VE is better (even though the outlet temp reduction is almost 2x the flow increase), but assuming you've tuned for it why does everyone keep saying a larger pulley on a V is like a smaller pulley on a III? The article tells us that couldn't be further from the truth, or is that just a general rule of thumb for people who are dropping pullies without tuning?

**SgtMarshal** · 02-06-2015

here is an illustration of what is said above:

http://www.regalgs.org/topic/54470-g...l=supercharger

**Booba5185** · 02-06-2015

Post 65 in that thread says that those charts and graphics were in an uncontrolled environment, so who knows. Like I said I'm no expert on the matter, but from what I have seen for the last 2 years. I do spend a LOT of time on the site, lol. The overall consensus has been the Gen V was the equivalent of a 0.2 pulley drop. Is that why I got it, hell no. My L67 took a **** and the L32+TB adapter was cheaper than a L67, with lower miles. Why is this all suddenly being questioned now?

**Booba5185** · 02-06-2015

So after some reading, Eaton says the Gen V results in a 9% increase in horsepower. Based off of the 240HP the L67 produces, that is 21.6HP. The general consensus that I've seen is that a 3.5 pulley will net ~20 HP. A 3.6 (or a swap to a Gen V) would be around 12-17HP increase, giving a 5-7% increase. Is it really that hard to believe? I don't think so. Eaton probably took credit for all the other improvements GM did, the larger throttle body, the better tuning, etc to get to their "9%" increase.

**99GT2dr** · 02-06-2015

http://www.clubgp.com/newforum/tm.as...heck=611555397

That thread offers some hard numbers, at least. I'm questioning this all of a sudden because I keep reading how pulley x on a Gen V = pulley y-.3 on a Gen III, with no real reasoning behind it (except "Gen V moar efficient!" which to me would mean being able to run a smaller pulley, certainly not pulleying up because in that case you might as well just keep your Gen III) And because Gen V's aren't stupid expensive anymore so I would actually consider using one now.

From what I gather, until you're running sub 3.0 pullies it's not worth it, my 3.2/xp/ssic/L36 setup puts out all the power I want from an M90. What I find hard to believe is that if your car is set up to run a 3.5 knock free, you can't just swap to a Gen V and tune the fueling a bit to compensate for the extra (and supposedly cooler) air to run knock free just like before.

**Booba5185** · 02-06-2015

I can't get to that link, but I see it from both sides. The VE of the Gen V is higher than the Gen III and it flows more (barely) at the same RPM, so if both blowers were sucking in the same amount of air, the Gen V will put OUT more under the same conditions. More is always better don't get me wrong, but I don't know if it makes as much of a difference as everyone says. Could I see 5-7% increase in power on an engine with no other mechanical issues, and in good running order? Possibly. An engine that has some bolt-ons already like rockers, headers, etc? Sure. I've always kind of considered a Gen V as a ported Gen III (from a performance stand point, not longevity and such).

I'm glad I started this, I'm learning a lot more than I expected, lol.

**SgtMarshal** · 02-06-2015

the advantage from running the gen v is because of volumetric efficiency. its making the same amount of power but with less effort from the engine. they did a few things to accomplish this, a bigger sc inlet, a bigger sc outlet and a better coating on the rotor pack. the more efficient the power adder is, the more power it can make.

**99GT2dr** · 02-06-2015

I'm not doubting the Gen V is better, don't get me wrong. If you go from a 3.5/Gen III to a 3.5/Gen V you will definitely gain power (gotta tune for it, obviously). But if you increase the pulley size after the swap you're not gaining anything, other than sound if you care about that sort of thing I guess.

Before and after scans (during the same time of the year) would give us a much better idea of how much more air it's flowing, and how much more fuel would be needed to compensate for said airflow increase. Was kind of hoping someone who does their own tuning, and has done the swap would chime in and provide some real world experience. I mean unless you were running rich before, headers will give you kr, too (leans out your afr with moving more air), but nobody goes up 3 pulley sizes when they do headers, they get a tune for it.

Why don't people that swap blowers do the same thing instead of throwing hp away putting on a bigger pulley?

**SgtMarshal** · 02-06-2015

this is why I dont think a gen 5 makes much difference. yes it flows more air, but you cant run as small a pulley, so what you are gaining in one place you are losing in another.

**16MustangVet** · 02-06-2015

Effeciency^^^^^^^^^ That is all that matters forget about the damn pulley size people!!!! Pulley X doesn't mean dick if it knocks no matter if its on a Gen3 or a GenV!!!

**ctracer** · 02-06-2015

it does though.
because the gen V is more efficient, it takes less work to achieve the same power.
less work is always better.

**Booba5185** · 02-06-2015

I think what it comes down to is people are relating pulley size to horsepower and knock. We drop pulley sizes to get more airflow, and that airflow\heat is what causes more horsepower and knock (heat). At the end of the day, the Gen V does flow more air on the same size pulley as a Gen III due to the VE being higher among other things (outlet\inlet\etc.). It's just how much of a difference there is, if I had my old Gen III and LIM I'd swap it on to do some comparison, but I don't, so oh well.

At least we are all being civil about this and no one has brought up the fact that the Gen V has a slightly cooler charge. I think we can all agree that makes no difference and if it does make a difference, it's not much. Probably the equivalent of driving naked opposed to driving clothed (I think I have an idea...).

**99GT2dr** · 02-06-2015

Only thing I was trying to get at from the beginning is that if you can tune your car, there is no reason in the world you can't run the same size pulley on a Gen V as you were on your Gen III before swapping (assuming you had no kr to begin with). If you had an overly rich tune before swapping, you may not even have to tune at all to run it kr free.

Let's also not forget about the '04+ timing tables compared to the 97-03's, that's certainly helping with that 260 hp rating. Another oddity is the TQ ratings being the same at 280, a 3.5 pullied Gen III car is for damn sure putting down more torque than that. I may have to search for some dyno sheets, not many people dyno stock vehicles, though.

**Booba5185** · 02-06-2015

^^^That's what I was saying earlier, I think Eaton was taking credit for EVERYTHING that was done to the 04+ to make them "faster". The Gen V was a contributing factor, don't get me wrong, but there are plenty of other things that helped get up to 260. For now I'm going to run the 3.6 and see how that works, and go down from there. I won't be surprised if I end up going smaller, but I'm going to play it safe.

At the end of the day, I'd bet if someone swapped a Gen V with a N* TB (or ported L67 TB), along with the 04+ tables\tune, they'd get a 21.6 HP(9%) increase. Like I said though, the Gen V is only one contributing factor to that 21.6hp.

**99GT2dr** · 02-06-2015

Sounds good, what are you scanning/logging with?

**Booba5185** · 02-06-2015

My Android based head unit and Torque Pro. I have it set up to sound an alarm (and fade out the music) if anything over 3* happens. Everything is hardwired to the head unit, and Torque Pro starts about 20 seconds after I start the car, every time.