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considering turbo cont.

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taylorbok

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Nov 10, 2008
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well I can no longer read my other thread so continuing here. I will upgrade my membership but I want other basic members to be able to see this.

Who has a picture of there pressure regulator referenced to the pipe? do ppl still do that, it sounds like a good idea to me.

for a mounting bracket I can just build a bracket to go from the compressor housing bolts to some where on the chassis?
 

Wheel House Motorsports

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Nov 27, 2007
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well I can no longer read my other thread so continuing here. I will upgrade my membership but I want other basic members to be able to see this.

Who has a picture of there pressure regulator referenced to the pipe? do ppl still do that, it sounds like a good idea to me.

for a mounting bracket I can just build a bracket to go from the compressor housing bolts to some where on the chassis?
im almost positive there are pics floating around in the carb turbo thread in perf/mod.. but your gonna have to break down to find em, unless someone feels nice enough to link em.
 
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taylorbok

Active member
Nov 10, 2008
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On the carb sleds I set up, I tap into the center section of the pipe and use the pipe signal to control fuel pressure rising rate.

1. it comes up faster than boost .
2. it should be 4-5 psi higher than boost to use the pipe correctly.
3. it allows lower standing fuel pressure and higher operating fuel pressure .
4. It allows you visual of pipe back pressure at any given boost level.

the pipe being 4 -5 higher at all times gives you that ,,plus boost to raise the fuel pressure.
example, 4 psi fuel, 10 psi boost = 14 psi feul under boost.
my system = 20 psi under boost at the same base of 4 to start..as pipe should be 14 + at 10 psi boost. so signal to regulator is 14 + rather than just the intake sides 10.

On carb sleds this also causes a rich condition when you bleed more boost as the fuel pressure will continue to climb and cause and inrichment condition that will save you from a lean out..

We typically will turn down the powerjet when jumping from 10 -18 psi rather than open it from lack of fuel volume..

Gus

I searched and searched but couldnt find it. Found this but cant find the picture again or your "how to"

Gus you've got mail.
 
J
Jun 13, 2009
1,032
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Hailey, Idaho
Thanks for keeping us fee loaders in mind. I've been wanting to go turbo for a while, but the RT was not a good choice, so I ended up with an 08 XP and trust me I'll be lurking around this post.... so take lots of pics for me :camera:
 
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taylorbok

Active member
Nov 10, 2008
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is this a proper pitot tube setup? (note not my setup found pic online)
Conations%20to%20plenum.jpg


do I have to run that large of line, I was thinking that I was going to run 1/8" hose to my carbs and wastegate, I guess I could start with a larger line and "T" off.

or would something like this be better
pitot.gif
 
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swrev

Well-known member
Jun 26, 2008
952
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Lewistown, MT
My turbo uses individual 1/8" lines off separate barb fittings off the airbox--except I do have my blow off valve and fuel pressure regulator t'd together off of the carbs, but I will be changing that and running fuel pressure off the pipe. I've never seen a setup w/ a pitot tube, so unsure if there would be any andvantage or disadvantage to doing it that way. It seems it would clean things up on a sled having to deal w/ more carbs.

Hope you don't mind if I ask a question on your thread--

Where have others taken vacuum off the carbs? I was curious if it would help to have them higher in relation to the slides. Mine are fairly low and I thought it might get a better vacuum signal if the fittings were higher.
 
G
Apr 23, 2008
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Just skip right over the pitot thing.. its ok but not as friendly as one might think...

reference bowls to airbox..end of issue


gus
 
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nuttyn01

Well-known member
Dec 3, 2007
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Sioux Falls, SD
BOV signal

Start by pulling signal from the motor side of the carbs if you havent done that already. There are two flat ports that lend themselves very well to being tapped by a 1/8" barb/10/32 tap. That solved my run on issues instantly as there is significant pressure differential when the slides drop. I have never measured to see if it actually creates a vacuum or not. If you have done this and your still running on then you probably need to soften the spring in your BOV.

I will post some pics tonight.

My turbo uses individual 1/8" lines off separate barb fittings off the airbox--except I do have my blow off valve and fuel pressure regulator t'd together off of the carbs, but I will be changing that and running fuel pressure off the pipe. I've never seen a setup w/ a pitot tube, so unsure if there would be any andvantage or disadvantage to doing it that way. It seems it would clean things up on a sled having to deal w/ more carbs.

Hope you don't mind if I ask a question on your thread--

Where have others taken vacuum off the carbs? I was curious if it would help to have them higher in relation to the slides. Mine are fairly low and I thought it might get a better vacuum signal if the fittings were higher.
 
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taylorbok

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Nov 10, 2008
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I cant decide to reference fuel pressure to pipe or to a pitot tube, either should yield a higher pressure to the fuel. decisions decisions.

I was told I can just connect the dpm ports to the airbox and that pressures the bowls.

Ordered all my supplies today from various sites which is a step in the proper direction but one large step backwards is the fact that my turbo came that I ordered from Forced performance came in and is not even close to the proper turbo, got a 3071 with a .60 ar and no tial housing when I ordered a 2871 .86 a/r with tial housing I am confused, either they messed up huge or I got someone else's turbo. :doh: hopefully get this sorted out here.

thanks guys.
 

Wheel House Motorsports

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pitot tubes work very well for getting a good signal, but the issues you can run into or I have in other applications is it works really well for getting a good strong initial signal, but then it gets way to high on peak as due to airflow the dynamic pressure is to high. The pitot tube issue is highly important in the yamaha carbs pictured. I ran the almost exact same set when i did my rx1 turbo kit and it was VERY picky about how it was setup, but again, TOTALLY different carbs and not needed on the 2 stroke setups.

I know on the XP we did, althought not ideal we just tapped into the airbox in a location that would see a strong flow hitting and turning at that particular location. it worked rather well, but when/if we redo it I think we might try swapping to the pipe.

and yes as nutty mentioned, if you pull the carbs out, and look at the back edges right before the ribbed peice(for reed boot mounts) there are nice flat spots, i think a set are even pilot holed so its perfect for drilling and tapping for setting up a pressure reference. I know people LOVE fancy BOV's, but the bosch plastic ones that a ton of stock turbo cars run work awsome. very fast reacting, light, and cheap.

bummer on the forced performance deal, I have always had awsome luck with them.. might have just been a stupid mix up, at least hopefully it was.
 
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taylorbok

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Nov 10, 2008
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sounds like a stupid mix up gotta send this one back and then they will get me my proper one, no big deal (hopefully)

I cant decide on boost reference for fuel pressure so many people doing it every way, maybe set it up to run each way plug them off and then try switching it around until I am happy with results.
 
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taylorbok

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Nov 10, 2008
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Who could I get to either make me a set of domes for my slp head or cut a set that I have to turbo domes?
and will whal bros sprockets hold up to the boost?
 
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J
Jun 13, 2009
1,032
218
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Hailey, Idaho
I'd think with a 146 the Wahls will hold for a while, Avid is the best bet if you want it to hold together ( not to mention they will run smoother than those whal drivers )

Could you get away with the SLP 0-3,000 ft domes? I know they have three different domes for there head ( I have the 3,000-6,000 domes in mine )... Or could you go with a stock head? I have a stock head laying around if that route would work out for you.
 
G
Apr 23, 2008
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Who could I get to either make me a set of domes for my slp head or cut a set that I have to turbo domes?
and will whal bros sprockets hold up to the boost?

you are good wth the oem head untouched for mountains and 100ll

I can do your slp domes $40 each
 
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taylorbok

Active member
Nov 10, 2008
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I have the 0-3000ft domes in there and a thick base gasket. I believe they are 12.5 : 1
I just put them on.

I had 13.5:1 (i think) when I blew it up so I went down for the turbo, I was thinking I could send my high comp ones that are a bit hagard from the locator pin jamming around in there and get them cut. would this work?

I wanna run the billet head to keep head/ coolant temps down (plus it looks cool :cool:) . I have stock head laying here as well.

I have quick access to the whal bros thats why I was asking might just order the avids but well see.
 
G
Apr 23, 2008
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The 12.5s are good
I can work the hagard units too..lol

If you plan on being 5000 ft and above for most of your riding I would use the 12.5s as is..100ll minimum,, up to 18 psi..

5000 and down you would like a lower comp but only down to around 11.5...its dome diameter that makes the most difference. slowing the burn speed to stave off deto..

Gus
 
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taylorbok

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Nov 10, 2008
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I'll just run what I have. I dont run at home often maybe once or twice a season (2500ft)

usually out in BC at 6-8000ft
 
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