2.6 Protrusion Consensus

nwpadmax

nwpadmax

Turbo Geek
OK, just tossing out something for your consideration and discussion. I am not exactly a protrusion rule fan, but the idea seems to be gathering steam in some areas.

I am already seeing variations on the protrude rule between Scheid / TS and say for example BOB and COTPC. Some of these are not set in stone yet.

I'm just going to ask / propose that if protrusion is the goal, can we at least have some consensus on how to do that? Like for example, would everyone have a cow if we said the SDX 2010 rules are the "standard"?

There are a million ways to skin a cat. But there seems to be no reason why Group A has to have protrusion with their interpretation of it, and Group B has something similar but not exactly the same. So a guy legal with A cannot pull with B without some slight change in the cover. That's just money spent for no damn good reason.

I just don't think we need to have different covers and/or wheels to go pulling in neighboring states. What is the point of that?

We need to keep folks on the same page and strive for unity in the sport. A number of groups all want to pull back the power in 2.6. That's fine. To have everyone doing it "their own way" seems entirely wasteful and takes us back to the days of exclusionary rules made to keep certain trucks out of certain areas. That's BS of the highest order.

Secondly, how about trying to run ONE set of protrusion rules for a minimum of 2 years?


I just think we're spinning our wheels and going backwards if the Protrusion movement doesn't go for some level of unification.

Discuss.
 
I have two problems with the protrusion rule, 1. cost, 2. still allowing the MWE. The one concern to going to a restrictor plate, anyone whom has incurred the cost to adapt to the protrusion rule may not be pleased to see that rule change to something so simple and cost effective.
 
As far as the restrictor plate being cheap, who has put a vacuum gauge at the turbo inlet. Depending on the vacuum you can pull it might not be as effective as the protrusion. IE you stick an HX82 behind it and it can pull a large vacuum your going to suck more air past the restrictor plate.

I am just thinking out loud here. Of course you have to have the air flow to drive the turbine to spin the wheel.

What other places have done restrictor plates on turbos? This might create a whole new set of issues, as the protrusion turbos are pretty mature as far as what works and what doesn't. If no one has done much with restrictor plates on turbos, it would require even more $$$ as you have to figure out the best setup.


Discussion?
 
Weston, it feels like it's almost too late in the game to get a restrictor plate concept in place. Seems like all the groups are wanting to solidify by November.

So time is running out on options, methinks.

I just look into the crystal ball and see once again we are in a Tower of Babel situation.
 
zstroken said:
As far as the restrictor plate being cheap, who has put a vacuum gauge at the turbo inlet. Depending on the vacuum you can pull it might not be as effective as the protrusion. IE you stick an HX82 behind it and it can pull a large vacuum your going to suck more air past the restrictor plate.

I am just thinking out loud here. Of course you have to have the air flow to drive the turbine to spin the wheel.

What other places have done restrictor plates on turbos? This might create a whole new set of issues, as the protrusion turbos are pretty mature as far as what works and what doesn't. If no one has done much with restrictor plates on turbos, it would require even more $$$ as you have to figure out the best setup.


Discussion?
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I am by no means a physicist, but my best understanding is that the beauty of the thin plate orifice is that there is irreversible pressure loss in going through it. Meaning, you can suck hard, and suck really really really hard, and the mass flow rate is almost identical. I have seen the compressor maps of LeMans restrictor plate turbos and they frickin' go vertical flatline on the right hand side of the map. There ain't no more to be had, period.

So there is a good science background to it.
 
nwpadmax said:
I am by no means a physicist, but my best understanding is that the beauty of the thin plate orifice is that there is irreversible pressure loss in going through it. Meaning, you can suck hard, and suck really really really hard, and the mass flow rate is almost identical. I have seen the compressor maps of LeMans restrictor plate turbos and they frickin' go vertical flatline on the right hand side of the map. There ain't no more to be had, period.

So there is a good science background to it.
Click to expand...


Interesting, I guess trying to put my feeble mind on it, is that more of a vacuum you pull the less dense the air is. Which would explain why the mass flow rate stays constant.
 
RAWdiesel said:
I like that idea. that way one turbo works in a large area.
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Yeah. I mean, I can see myself having 2 wheel/cover setups at the most, and I might have to be a little lucky to be able to buy those.

Any more than that, I just ain't going. I think a lot of people are in the same boat.

If we don't have some sort of unity, the numbers will go down again, caused in part by our inability to agree on something that's not that complicated.
 
zstroken said:
Interesting, I guess trying to put my feeble mind on it, is that more of a vacuum you pull the less dense the air is. Which would explain why the mass flow rate stays constant.
Click to expand...

Yes, the other way to think about it is, any time you do turbo sizing, you need to know P1 and P2 (pressure in and pressure out) as well as T1 and T2....for both sides of the charger.

Most people just assume P1 is atmospheric on the compressor side and forget about it. But you drop P1 into vacuum and guess what, P2 drops as well (duh, pressure ratio). And I would venture to guess that T2 probably suffers as well.


But again I think we are running out of time for this because there's not much more test 'n tune time at at the tracks unless you live way south of here.
 
So basically the differences right now are COTPC is .250" map and 1/2" long 2.6 bore, SDX is a .200" map, and BOB is .250" map and 3/4" long 2.6 bore. All being 1/8" protrusion. One set of rules would be better!
 
White Duramax said:
So basically the differences right now are COTPC is .250" map and 1/2" long 2.6 bore, SDX is a .200" map, and BOB is .250" map and 3/4" long 2.6 bore. All being 1/8" protrusion. One set of rules would be better!
Click to expand...

COTPC has said that they also want a specific location of the groove relative to "the step in the wheel." I sent a PM to p-pumped (Ted) to see what's up with that one.

I understand the reasoning but again, what are we looking at? 3 covers per truck to run the heartland of pulling? It's excessive, and exclusionary, IMHO.

When it comes right down to it, I could live with 2 sets of rules - one should be NADM as it stands because everyone can run that, and secondly, a set including one form of protrusion rule.

The comparisons would be elightening to see.
 
The thing about protruding the wheel and then not stating where the map is or isn't allowed to be, is if your map is feeding the front of the 3.0-3.2-3.9 wheel then you are right back in the same boat as your in this year. Take the guess work out of it and it will be a much easier and fair class to tech. jmo. I thought I was wrong once but turns out I was mistaken
 
To me if you had one cover that had a .200 map and 3/4 long 2.6 bore with 1/8 protrusion wouln't you be able to pull at all places?
 
Smokem said:
I have two problems with the protrusion rule, 1. cost, 2. still allowing the MWE.
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I have to agree with Weston. This is in no way what I *****ed for. Still putting money in the wrong hands and I really don't see where it's going to change much.
 
Myself and a few others will buy/machine what ever it takes to try and be on top. If its different wheels and covers than so be it. I don't want it that way! I would love the same rules everywhere I go to hook. I've seen some protrusion 2.6 chargers that are more than capable of making the same amount of power that the current non protrusion chargers are.
IMO all these new rules are doing is making people spend more money in the end.
 
ABI MOTORSPORT said:
The thing about protruding the wheel and then not stating where the map is or isn't allowed to be, is if your map is feeding the front of the 3.0-3.2-3.9 wheel then you are right back in the same boat as your in this year. Take the guess work out of it and it will be a much easier and fair class to tech. jmo. I thought I was wrong once but turns out I was mistaken
Click to expand...

I agree with what you're saying. I asked Ted if it would be simpler to state that the leading edge of the MWE groove needs to be behind the tips of the compressor....i.e., a somewhat legit MWE, not an air entrance groove.

So while I agree with the concept, we still have like 3 different thoughts on this and I want to try to get to unification, somehow, if that is even possible.
 
ABI MOTORSPORT said:
The thing about protruding the wheel and then not stating where the map is or isn't allowed to be, is if your map is feeding the front of the 3.0-3.2-3.9 wheel then you are right back in the same boat as your in this year. Take the guess work out of it and it will be a much easier and fair class to tech. jmo. I thought I was wrong once but turns out I was mistaken
Click to expand...

i agree with rocky y not just have 2 3.0 classes and quit pissin with covers that aint doing anything to hurt the turbo!
 
My opinion;

2.6 Class
inducer bore must be 2.6" for it's entire length
wheel must protrude 1/8"
limit turbine housing to T3/T4
limite single 35" tire
S300 MWE allowed
S400 MWE prohibited

The other classes are another story.
 
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