FAQ: Ported Blower vs. Gen V?

i've seen others make a reference to it, can anyone explain it?

http://www.zzperformance.com/grand_prix/products1.php?id=162&catid=106

has anyone had this done? how much of a difference are you feeling? i'd like to have it done before going down in pulley sizes

Imo, porting is a very good thing, but have it done by someone who specializes in the M90 blower. ZZP seems like the best choice. It's a KR reducing mod, so you can run a little more boost safely. If I ever find an IC package for the right price, I'm definitely having someone port the blower while it's off the car.

I ported My SC myself. Mostly removing the rough casting on the inlet and outlet. I noticed better throttle response and slighty diffrent whine.
You can find many threads on clubgp on how to port an SC. But be careful some have turned their SC's into paper weights. Overall like AA said it is a KR reducing mod.

yeah I was planning on having it done at zzp, the descrip. says 15% more power then a none modded blower, sounds really good for the 200$ price tag.. but would getting it off be tough? you'd have to remove all the fuel rails and crap

Their claim is a little misleading. What they actually said is: the highest dynoed M90-powered car makes 15% more power than any other dynoed car not using a ZZP ported M90. That leaves out lots of other variables. ZZP wants you to believe their port job made the difference, but they can't prove it. What if their car had a better-flowing exhaust than the competition? What if there are non-dynoed cars that are running better track times?

That said, it's still a good mod. It's hard to gauge the power increase because it will depend on the rest of your set-up. A 15% gain would equal 36 hp on a stock engine, which I assure you isn't going to happen from just porting. But if it lets you drop a pulley size safely, that's a worthwhile use of $200.

Taking off the blower isn't that bad. I've taken the rail off mine without much problem. I'd think the blower should be cake after that.

they say they only want 97+ m90 blowers, why is that? do they just mean the 97+ GTP and regals? b/c i'm 90% sure the 96 and 97 rivs have the same blower, except for different vac lines.

A 95 riv 1 engines, these have a smaller M62 Eaton blower. These are totally different the the 97+. Pontiac didnt get the L67 till 97.

There are two versions of the M90, the earlier and the 98+. The only difference is the vac line routing. The 97 has a vac tree near the boost bypass valve. You can easily convert a 97 to work on a 98+ engine and vice-versa.

Since you have a 97, just get a 97.

Also, a lot of people are converting to GENV M90 superchargers, which means this is a good time to pick up a used one for cheap.

how much more efficient are the gen 5?

About 20 hp worth.

i saw on intense they had a ported gen 5 setup for around 500, basically paying 300 for a brand new gen 5

anyone know how long it takes them to port your blower and return it too you?

I was worried about that too, i'd have to find alternative transportation :>

Or you can buy a core blower housing on clubgp for $70 then sell your old S/C casing on club gp.

AA wrote:

About 20 hp worth.

I've also read that you need to be much more careful about pulley swaps with a Gen V, because it is so much more efficient than our older M90's. Something like a 3.6 on a Gen V is like putting a 3.4 on a Gen 3 blower?

Interesting. I've heard from a good source that some Gen V GTPs have KR in stock form. It's probably why they made the 3.5"/3.6". Used to be the 3.4" was the biggest.

interesting...i wonder what could be causing the KR on a more efficient blower? isn't the air charge cooler with the gen V due to less parasitic loss?
all cars have KR at some point, thats why they invented the knock sensors, but just how much tuning is required on the avg. car off the plant line? the world may never know... but i'm guessing cars would last longer if they did check each one.
(i know they run every vette on a dyno to make sure it's within the hp/tq range but does anyone know if they do that for all cars?)

I don't know if most cars are dynoed for max power, but many are checked up to a point. I watched the Civic being manufactured at the Marysville, OH plant. They were coming off the line close to two cars per minute, and each one was driven onto a dyno and taken up to a pretty high speed, at least 80 mph. I think they were measuring parameters vs. speed, vs. transmission behavior, but I'm sure power could also be evaluated.

The Gen V is more efficient, but it also moves more air, so more fuel needs to be added. If the PCM wasn't updated sufficiently, I can see how KR could happen. There's evidently something going on, as I found this info inside Wikipedia's Buick V6 entry:

"The L32 is a supercharged Series III. Introduced in 2004, the main differences between the L67 and the L32 is the L32's electronic throttle control, slightly improved cylinder head design, and updated Eaton supercharger, the Generation 5 M90. HP output is up to 260 hp in the Grand Prix GTP, though an inferior fuel supply system, and excessive torque management in the PCM, results in the 2004+ being no faster than the 1997-2003 Grand Prix GTP in stock form."

Here's a cool write-up for swapping to the Gen V:

http://www.davetech.net/car-gen5.htm

The VCM tables are ridiculous if you've ver seen all of them. Its twice as crazy for an LS6. Installing a GenV is easy, you just need to get an L32 manifold or cut out an l67 manifold. Tuning could be more difficult, but the big change is the VE tables. The boost curve is going to change. As for what is better, The Gen V all the way!!! if you look inside one, youll know why.

thanks for all the info guys, especially that guide, i'd rather save the money for a gen 5 and then have it ported rather then have my gen 3 ported and end up wanting a gen 5 later on down the road..

That's one way of looking at it. The other is that you'll need a different LIM ($) to use the Gen V ($), and the porting ($) vs. the cost of just porting the blower you have. Ported Gen III = almost as good as ported Gen V for less $.

If money is no object, why not go M112 or whipple?

oh money is very much an object, 19 living on my own is tough lol, but if the gen 5 is good for 20 hp, that's quite a gain

AA wrote:

That's one way of looking at it. The other is that you'll need a different LIM ($) to use the Gen V ($), and the porting ($) vs. the cost of just porting the blower you have. Ported Gen III = almost as good as ported Gen V for less $.

If money is no object, why not go M112 or whipple?

It doesnt cost anything to cut the hole bigger in the manifold if you already have 3 dremels and multiple cutoff wheels. I wouldnt even bother porting the intake manifold. the design is so crappy that no amount of porting is going to achieve and greater power. I left mine stock and ported my cylinder heads so that the overlap prevented blowback. If money is no object, its turbo all the !!!!!

quote: "If money is no object, its turbo all the !!!!!"

Except for being a functional daily driver, can't argue with that!