34mm Restrictor Solutions? Now I have my GT2871R - which means I also need a restrictor. I'd like to keep it removable so I can runt 2 maps (one for track/hill climb, one for rally w/restrictor). I'd like to make sure the restrictor also does not create strange turbulence as air approaches the impeller. My thinking is that the GT2871R is popular enough that this has been done by lots of folks? Thanks, Vittorio - https://www.rallyanarchy.com/phorum/read.php?5,52126,52126#msg-52126 Tue, 07 Apr 2026 00:53:56 -0500 Phorum 5.2.15a https://www.rallyanarchy.com/phorum/read.php?5,52126,53902#msg-53902 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,53902#msg-53902
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vbares
Toyota used a combination of mechanical capabilities in the restrictor plus, and here's the real trick, that extra air was enabled by installing the intake hose. So, during inspection - all aspects passed even during the rally...genius!

Yeah, as soon as the 1987 Audi 4k with locking diffs and bitchin suspenders starts threatening the front runners - I'm sure everything will be scrutinized :spin:

Atta boy, give 'um hell !!!]]> heymagic Construction Zone Fri, 19 Aug 2011 11:40:29 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,53901#msg-53901 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,53901#msg-53901
Yeah, as soon as the 1987 Audi 4k with locking diffs and bitchin suspenders starts threatening the front runners - I'm sure everything will be scrutinized :spin:]]> vbares Construction Zone Fri, 19 Aug 2011 11:35:16 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,53897#msg-53897 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,53897#msg-53897
If you swap out a turbo in service it should be inspected by tech at that time. Not all events have the manpower to do that. I usually hang around service and watch. Hurst does the same.

There is never a sure way that humans can't find a way to cheat, its in our nature. NASCAR, WRC and F1 have amazing tech procedures and budgets to support them and still people get caught cheating or out of compliance (I think there is a difference...intent).]]> heymagic Construction Zone Fri, 19 Aug 2011 10:44:00 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,53894#msg-53894 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,53894#msg-53894 Andrew_Frick Construction Zone Fri, 19 Aug 2011 10:13:55 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,53881#msg-53881 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,53881#msg-53881 DaveK Construction Zone Fri, 19 Aug 2011 00:35:34 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,53876#msg-53876 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,53876#msg-53876
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john vanlandingham
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A1337STI
is wired and sealed better for the competitor? less likely to have it fall off? or more of a "it hasn't been tampered with" for the techs ?

Its proof positive if it HAS been tampered with...

Of course some well establish, high end preparation shops have been reported frequently enough to posses wire and lead seals and a goodly collection of paints......but Shirley I cannot comment.

I haven't heard of that, I suppose it is possible though. We do spot checks along the route and impound the cars at finish so I really doubt if people try it.]]> heymagic Construction Zone Thu, 18 Aug 2011 23:36:28 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,53871#msg-53871 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,53871#msg-53871
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A1337STI
is wired and sealed better for the competitor? less likely to have it fall off? or more of a "it hasn't been tampered with" for the techs ?

Its proof positive if it HAS been tampered with...

Of course some well establish, high end preparation shops have been reported frequently enough to posses wire and lead seals and a goodly collection of paints......but Shirley I cannot comment.]]> john vanlandingham Construction Zone Thu, 18 Aug 2011 22:43:30 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,53867#msg-53867 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,53867#msg-53867 A1337STI Construction Zone Thu, 18 Aug 2011 22:36:33 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,53855#msg-53855 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,53855#msg-53855 heymagic Construction Zone Thu, 18 Aug 2011 17:36:55 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,53851#msg-53851 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,53851#msg-53851
3.13.2 Restrictor Specifications
1. All turbocharged cars listed as requiring restrictors must
be fitted with a restrictor fixed to the compressor housing
unless the compressor air inlet internal diameter is equal
to or smaller then the required restrictor internal
diameter.
2. All air used for feeding the engine must pass through
this restrictor.
3. The restrictor must be maintained for a minimum
distance of 3 mm measured downstream of a plane
perpendicular to the rotational axis situated at a
maximum of 50 mm upstream of a plane passing
through the most upstream extremities of the wheel
blades (see Appendix B drawing 254-4).
4. The required diameter must be complied with regardless
of the temperature conditions.
5. For the installation of the restrictor it is permitted to
remove material from the compressor housing and to
add material for the sole purpose of attaching the
restrictor onto the compressor housing.
6. The restrictor must be made from a single material.
7. The restrictor may be pierced solely for the purpose of
mounting and sealing, which if done must be carried out
between the mounting screws, between the restrictor (or
the restrictor/compressor housing attachment), the
compressor housing (or the housing/flange attachment)
and the turbine housing (or the housing/flange
attachment) (see Appendix B drawing 254-4).
8. In case of an engine with two parallel compressors, each
compressor must be limited to a maximum intake
diameter of 22.6 mm.
9. Diesel engine: For vehicles with diesel engines, the
restrictor must have a maximum internal diameter of 35
mm and an external diameter of 41 mm.
10. Championship Options - A championship may elect to
require tighter scruitneering control of the restrictors. If
so stated in the championship regulations, the following
rules also apply: The external diameter of the restrictor
at its narrowest point must be less than 38 mm, and
must be maintained over a distance of 5 mm to each
side.The mounting of the restrictor onto the turbocharger
must be carried out in such a way that two screws have
to be entirely removed from the body of the compressor,
or from the restrictor, in order to detach the restrictor
from the compressor. Attachment by means of a needle
screw is not authorized. The heads of the screws must
be pierced so that they can be sealed.
11. Restrictors in Group N cars must meet all Group N
regulations.]]> vbares Construction Zone Thu, 18 Aug 2011 16:53:05 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,53837#msg-53837 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,53837#msg-53837 heymagic Construction Zone Wed, 17 Aug 2011 23:58:48 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,53742#msg-53742 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,53742#msg-53742
What's with the lead seal? Is that for making sure that the restrictor is not tampered with during the event? I've typically seen that done with a paint marker ? New regulation I'm not aware of?

AJ - good news on the bearings !]]> vbares Construction Zone Tue, 16 Aug 2011 11:19:41 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,53741#msg-53741 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,53741#msg-53741
You need to replace those set screws with Bolts. I like to use Socked Head Cap Screws (Allen head bolts), and drill a hole through the head so you can pass mechanics wire through. Really, the wire should go through both screws, and then be "tied" to the turbo. What i did there was drill a small hole through the corner of "number plate" boss on the intake housing (where they would generally rivet/engrave a part no on the housing).]]> Do It Sidewayz Construction Zone Tue, 16 Aug 2011 11:04:15 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,53739#msg-53739 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,53739#msg-53739
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vbares
I should really reduce the size of those pics eh? :spin:

Yes please..... still need to provide a way to seal the screws with safety wire and a lead seal.

I mark the turbos at regional events with paint but at nationals it needs to be done correctly.]]> heymagic Construction Zone Tue, 16 Aug 2011 10:48:31 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,53737#msg-53737 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,53737#msg-53737 vbares Construction Zone Tue, 16 Aug 2011 10:31:39 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,53736#msg-53736 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,53736#msg-53736
There are 2 of them placed in such a way that they can be:
a) visually inspected
b) accessed

easily from the motor side.]]> vbares Construction Zone Tue, 16 Aug 2011 10:29:46 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,53735#msg-53735 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,53735#msg-53735 heymagic Construction Zone Tue, 16 Aug 2011 10:20:25 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,53730#msg-53730 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,53730#msg-53730
Make sure you get all those likes as far away from the exhaust housing as you can!]]> Do It Sidewayz Construction Zone Tue, 16 Aug 2011 08:58:39 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,53729#msg-53729 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,53729#msg-53729 aj_johnson Construction Zone Tue, 16 Aug 2011 08:55:29 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,53721#msg-53721 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,53721#msg-53721 vbares Construction Zone Mon, 15 Aug 2011 22:53:28 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,53720#msg-53720 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,53720#msg-53720 vbares Construction Zone Mon, 15 Aug 2011 22:50:40 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,52275#msg-52275 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,52275#msg-52275 Do It Sidewayz Construction Zone Thu, 14 Jul 2011 13:46:16 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,52267#msg-52267 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,52267#msg-52267
Doug]]> Doug Heredos Construction Zone Thu, 14 Jul 2011 11:51:10 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,52265#msg-52265 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,52265#msg-52265
http://www.raetech.com/Restrictors/I...estrictors.php

But interesting...]]> vbares Construction Zone Thu, 14 Jul 2011 11:38:13 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,52256#msg-52256 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,52256#msg-52256 vbares Construction Zone Thu, 14 Jul 2011 06:52:02 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,52248#msg-52248 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,52248#msg-52248
In the last post I think the rate of change of the flow direction is a bit sudden in the narrow center band. Air does not like sharp edges at the front end of the flow.

I always wonder would there be any benefit to introduce an energized air flow via vortex generators to keep the compressor blades from stalling? I guess it depends on what is really the limiting factor, is the pressure on the back side of the compressor getting down to 0 or is there cavitation and stalling of the blades due to thin air or high angle of attack as the air stream speeds up?

Guess I should have taken a few more classes... all my design experience is on single membrane foils called sails.]]> derek Construction Zone Wed, 13 Jul 2011 23:11:31 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,52246#msg-52246 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,52246#msg-52246
Overall length is just under 4" - convergent angle is 21 degrees out to a 3" inlet.

Will it work?]]> vbares Construction Zone Wed, 13 Jul 2011 22:23:49 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,52244#msg-52244 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,52244#msg-52244 AaronJMcConnell Construction Zone Wed, 13 Jul 2011 21:59:27 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,52228#msg-52228 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,52228#msg-52228
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urr
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DaveK
For what its worth, the TR30R turbo I've got has an opening of 48mm, so the stuff you guys are starting with is huge!

Dave - Are you saying that your compressor housing intake started life at 48mm? Once you stuff the restrictor in it, the original opening doesn't really matter. I'm not sure I follow.

The housing right around the turbo blades is 48mm and the housing doesn't get any bigger than that as it moves away from the blades. The housing is machined such that when the restrictor bolts in its sitting right at the outer plane as the blades (look for reflection of the blades in the pic with the 48mm intake). You can kinda tell what I'm describing (poorly) if you look at the picture of the restrictor sitting by itself.

Dave]]> DaveK Construction Zone Wed, 13 Jul 2011 17:28:21 -0500 https://www.rallyanarchy.com/phorum/read.php?5,52126,52224#msg-52224 Re: 34mm Restrictor Solutions? https://www.rallyanarchy.com/phorum/read.php?5,52126,52224#msg-52224
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Do It Sidewayz
If you search on Special stage enough, you'll find info from a Garrett Engineer.

He mentions that the "diffuser" after the 34mm choke point is critical, and that 7degress is optimal, but below 10 is still good. You are going to be pretty much limited but the 50mm away from the impellor.

FYI, the only thing i've ever machined on the housings have been drilling/tapping holes to hold the restrictor in.

The gentleman you're referring to is Mike, a CRS rally guy who works at Garrett. He's the one that helped me select my turbo.

To get the turbo side of the restrictor to run out 7 degrees all the way to the impellor, and keep the choke point 50mm away, I had to machine my housing. I seem to recall that there is a "step" in the OE housing that may create turbulence if you don't run the restrictor all the way up to the impellor. It's been a couple years since I did all the research etc on it.

Andrew

edit - the inside of intake housing tapers the entire way to the impellor, hence the reason we machined it. It was either that, or taper the restrictor. It may be the 2860 has a straight intake housing.]]> urr Construction Zone Wed, 13 Jul 2011 17:04:36 -0500