Why do split profile wheels; ww, ww2, 6/6 wheel do poorly with ported housings? I've been digging deep into different forums, PSA, PSN, Dieselstop, and here, and cant find an answer. All I read is that people lose boost with a ww and ported housing setup, yes i Know that wheel is outdated but it sill boggles my mind. I did read some threads about the ww2 not performing as expected with ported housings, so poorly that they went back to the stock wheel, and I cant find an answer as to why. I havent found anything about Riffraffs 6/6 wheel used with ported housings, although i was almost the guinea pig for that one. I would love it if somebody could explain why this is so.

I know the ported housing has a 4" inlet but theres still a 3" ring around the compressor wheel, so really all this is doing as allowing more air to get to the compressor wheel, its not actually allowing the turbo to move more air. they claim a 13% increase in choke flow for the ported housings, but why does it seem to adversely effect wheels that have tall and short blades?

 

We originally started installing the split wheels as a cure for surge. Back before there were upgrades to the housings available hot chips an the .84 housing would easily overspeed the stock wheel and stall it. The split wheel flows less than stock..... So it doesn't choke out as easily at higher rpms. Add bigger housings on both ends and your low flow wheel flows even less.

Admittedly I haven't really kept up with the recent wheels and what they are capable of...... But that's the origin story as I remember it.

 

I understand turbos, but I am unfamiliar with almost all of them. That being said, I believe Cookie88 hit it. Why is there a ported housing to begin with? The ported housing would be there to correct for surge. The wheels from Riffraff are designed to prevent surge as well. So you take a turbo with a housing modified to address surge, then you modify the modification by putting in a wheel designed to prevent surge. That's like jacking up the truck to improve the wheel clearance, then installing smaller tires after that.

Turbos work best when the clearance between the blades and the housing are crazy-close. A small increase in clearance makes a dramatic change to the performance.

 

thats just the thing, theres still the inlet part of the ported housing that sits tight around the wheel and this is where im getting hung up. so technically the wheel is still using a 3" inlet. is it because that inlet is not as extended outward as the stock housing? or is there that much of a clearance difference between that inlet and the stock housing inlet?

 

I dont think clearance is the reason for the difference in wheel performance - they are all designed to hug the walls. Those new wheels are designed to flow less than stock to address surge. They actually grab less air, right?

I'm looking at getting the ported housing wheel from riffraff that should flow more than stock, and should take advantage of the added flow possible with the ported housing over stock, but not flow so much that surge is re-introduced. That and the 1.0 exh housing I have from bfife should make for a good improvement to support 160/30 or 160/80 sticks one day.

 

The new wheels, whicked wheel 2 and riffraffs 6/6 wheel I'm not sure if they flow less air, the ww2 was tested in a truck with stage one injectors and made more boost than the stock wheel so does that mean it flows more? But if it flows more how does it address surge?

There's an increase in choke flow from the ported housing, but what does that necessarily mean? I've always thought that meant it was just an increase to the inlet of the turbo cause the overall inlet is 4"

 

I wonder if the answers might be in Garrett's literature. Here's one link I found:

http://www.turbobygarrett.com/turbob...Tech%20102.pdf

 

Stage 2 injectors I believe....

 

No it was stage one sticks, stock wheel was 32 psi and the ww2 made 42 psi

 

I wish..... I can't even break 21 psi....

 

it has to have something to do with how the air is entering the inlet portion to the compressor wheel, thats the only thing in that PDF that can shed some light on why the split profile wheels dont do well with ported housings

 

Your on stock sticks with no tuning, your lucky you have 21 most guys see 15-17 stock with no tuning.

 

Yeah Dylan, You are going to soil yourself when you finally get a chip. You have done all that stuff to your truck to prepare, and that is great, 17 PSi is the most that most guys see on a stock tuned truck, so trust me, your face is going to light up when you finally chip it. The smile is going to be wide and last a long time. You THINK you like your truck now, you are going to love it when it really wakes up.

Sorry for the highjack.

To the OP, there is something to be said for the compressor map as well. While the original WW made less overall boost, it made slightly more usable boost at lower rpm. It's not ALL about maximum boost, it's where the boost comes in that makes it useful.

I remember when Honda came out with the s2000. It ran a 1/4 mile in something like 3 tenths of a second slower than a Corvette. That was with someone who knew how to use the HP that came in at very high RPM's. It wasn't very useable on the street but it had high HP numbers. My point is, there is more to it than just the top numbers.

 

and i understand that, i hope its not coming off that im going at this from just a max boost standpoint, I was really hoping somebody would mention the compressor map because i know that it is a big deal with turbos. so when you change housings, and different wheel styles, your effectively changing the compressor map correct?

 

Absolutely Mitch. I am no expert on this topic for sure, but I know some basics. The basic map is effected by lots of variables. In a way it is like a torque curve on a dyno sheet. For those of us that DD our trucks, we would want a broad full map. For guys who sled pull or drag race, they would want something a little more specific to the upper RPM range because that is where they will need their boost the most. They don't spend as much time doing what they have their trucks built for in the lower RPM range.

Garrett has some very good reading on turbos. I highly recommend it.

Basic turbo tech

Advanced turbo tech

Turbo tech expert