Bypass Restrictor Recommendations

So I installed my bpipe today with dual cooling and the following diagram shows how I routed my cooling lines.

I was wondering what kind of restrictors I should run at the end of the cooling lines.

I was thinking a 4mm on the line coming from the headpipe/stinger and a 3mm on the line coming from the back of the cylinder head.

It's a stock 701 with an ADA Head (35cc) and stock 38's.

Any recommendations would be greatly appreciated.:biggthumpup:
 

Attachments

  • b-pipe3.jpg
    b-pipe3.jpg
    45.2 KB · Views: 97
Last edited:
I doubt it matters, but I primarily ride between 70F and 90F. I doubt a 20 degree change would require a restrictor modification, but I'd like to hear anyones opinion on whether it might actually require a restrictor change.

Thanks.
 
Come on guys. I know there are a ton of guys out there with my exact setup. I realize I am going to have to do some tuning myself, but I am just trying to get a good starting point.

What restrictors are you running, what water temp are you riding in, and what's your bypass water temp (if you know it).

Thanks:biggthumpup:
 
F

Freestyleriverrat

Guest
I run a 4mm restricton on my bypass pisser and a 6mm on pisser comming off the cylinder. However, I run 1 line into the cylinder and the other into the bottom of the head pipe.
 
I run a 4mm restricton on my bypass pisser and a 6mm on pisser comming off the cylinder. However, I run 1 line into the cylinder and the other into the bottom of the head pipe.

Appreciate the reply.

I thought about doing that, but I decided to have both go to the manifold because I am using it as more of backup system. I think both ways have their advantages, but like I said I'd rather take the safer route.

Now I just need to make sure I am not cooling the engine too much. I plan on ordering 3 of those Jetworks restrictors for before the 2 pissers and before the stinger. I just have to figure out what size restrictors to put in there. :dunno:
 
C

CG Racing

Guest
Didn't you already ask Art about this? Do you think that he may be misleading you?
 
Didn't you already ask Art about this? Do you think that he may be misleading you?

Actually I asked Art for a single cooling restrictor recommendation. When I order those restrictors today I'll ask Art for another recommendation. So no I don't think Art is misleading me.

It doesn't hurt to hear what other people are running with similar setups.
 

crammit442

makin' legs
Location
here
Actually I asked Art for a single cooling restrictor recommendation. When I order those restrictors today I'll ask Art for another recommendation. So no I don't think Art is misleading me.

It doesn't hurt to hear what other people are running with similar setups.

You already have the routing that Art gave Brad. Your setup is almost identical to Brad's so run what he's running and stop talking about it already!:banghead: :banghead: :banghead: :banghead: :banghead:

Charles
 
F

Freestyleriverrat

Guest
protec reccomended a 4mm pisser for the bypass........I think Art reccomends the same. I talked to him a while ago about it and I am pretty sure he said 4mm on the bypass mounter inline before the FCV. The rest will depend on your setup.
 

SuperJETT

So long and thanks for all the fish
Location
none
It doesn't matter what someone recommends, you size your restrictors based on exit temperature out of the engine. Period.

If you have too small restrictors, you'll run hot, if you're too large, you can cold sieze. You start somewhere (no restrictors), then go from there based on what is coming out of the engine.
 

SuperJETT

So long and thanks for all the fish
Location
none
whats the ideal temp out of the pissers suppose to be?

Not out of the pissers, out of the engine. There could be a difference depending on your routing.

My old engine builder liked 120F which to me is where I can only hold my hand in it for a second or two.
 
120 to 130 So I have heard but I keep my water about 100. On an average 120 degree water after you run the motor hard for a bit then put your foot in the water it burns. So I keep mine low enough that it doesn't bother you
 

crammit442

makin' legs
Location
here
It doesn't matter what someone recommends, you size your restrictors based on exit temperature out of the engine. Period.

If you have too small restrictors, you'll run hot, if you're too large, you can cold sieze. You start somewhere (no restrictors), then go from there based on what is coming out of the engine.

That is only your opinion. In my opinion, it absolutely matters what someone recommends.(assuming they know what they're talking about) This business of designing your cooling system yourself is a load of crap for most of us. 99% of us here do not have the years it takes to understand all the variables that play into what should or should not be done to insure max performance, you and me included. There are other factors besides just temp that play into what is best for each setup. Pressure regulation plays a large role also. The vast majority of the people on this board should establish a good relationship with the builder/ tuner of their choice and go with what is recommended. Whether it be Paul, Chuckie, Art, or someone else is up to each of us. That's part of what we pay them to do. Most of the advice given here is sloppy guesswork at best. But hey, go for it if you believe you're smart enough to figure it out on your own. Why reinvent the wheel if you don't have to.:rolleyes:

Charles
 
Last edited:

SuperJETT

So long and thanks for all the fish
Location
none
That is only your opinion. In my opinion, it absolutely matters what someone recommends.(assuming they know what they're talking about) This business of designing your cooling system yourself is a load of crap for most of us. 99% of us here do not have the years it takes to understand all the variables that play into what should or should not be done to insure max performance, you and me included. There are other factors besides just temp that play into what is best for each setup. Pressure regulation plays a large role also. The vast majority of the people on this board should establish a good relationship with the builder/ tuner of their choice and go with what is recommended. Whether it be Paul, Chuckie, Art, or someone else is up to each of us. That's part of what we pay them to do. Most of the advice given here is sloppy guesswork at best. But hey, go for it if you believe you're smart enough to figure it out on your own. Why reinvent the wheel if you don't have to.:rolleyes:

Charles

Believe it or not, I do have the background for figuring out water routing, it's called years of heat transfer/fluid flow classes and experience.

Just blindly following someone's advice that a 4mm restrictor is fine, then going from 50F to 80F water or vice versa *could* result in major engine damage. Learning to check your outlet temperature which is a very basic measurement/test can save a lot of headache.

The problem with saying "use a 4mm restrictor" is that may work for that specific routing with that specific water temp/type (salt vs fresh), and as you mention, there are so many factors involved (i.d. of the fittings used which varies quite a bit, where the pump is tapped, etc etc) that it may not be a valid recommendation, plus Art or Paul or Chuckie or whoever may have done that setup in completely different water temperature than the end user, or not understand that they ride 50F water in early spring.

In the end, it's better to learn a little and understand what's going on and get the end result which is enough water pressure to prevent hot spots from localized boiling and proper engine operating temperature.

Or just install a thermostat!:Banane01:
 
F

Freestyleriverrat

Guest
It doesn't matter what someone recommends, you size your restrictors based on exit temperature out of the engine. Period.

If you have too small restrictors, you'll run hot, if you're too large, you can cold sieze. You start somewhere (no restrictors), then go from there based on what is coming out of the engine.

4mm is for the bypass so you keep adequate pressure built up in the line to operate the FCV properly. Anymore than 4mm may bypass to much water. The ID line is only just above 6mm. Superjett is correct about adjusting the rest based on engine temp
 
Last edited by a moderator:
That is only your opinion. In my opinion, it absolutely matters what someone recommends.(assuming they know what they're talking about) This business of designing your cooling system yourself is a load of crap for most of us. 99% of us here do not have the years it takes to understand all the variables that play into what should or should not be done to insure max performance, you and me included. There are other factors besides just temp that play into what is best for each setup. Pressure regulation plays a large role also. The vast majority of the people on this board should establish a good relationship with the builder/ tuner of their choice and go with what is recommended. Whether it be Paul, Chuckie, Art, or someone else is up to each of us. That's part of what we pay them to do. Most of the advice given here is sloppy guesswork at best. But hey, go for it if you believe you're smart enough to figure it out on your own. Why reinvent the wheel if you don't have to.:rolleyes:

Charles

Charles,

Hey man you know I highly value your opinion. You have helped me out more than anyone and I can't thank you enough for that.

I agree that Art definitely knows his stuff, but there is absolutely nothing wrong with a thread to discuss alternative ways.

I tend to agree with Superjett about the temps. How did Art come up with his recommendations? :dunno: I'm guessing he didn't just pull the numbers out of his a$$.

I was just trying to get a good thread going that listed people's cooling setup, restrictors, and temps that they were running.

I don't mean to be a$$hole, but the point of a forum is to discuss things. Nothing to do with you, but I get so sick and tired of people getting pissed off if someone didn't "SEARCH HARD ENOUGH FOR AN ANSWER".

Until last week I had no idea I was suppposed to run restrictors with an exhaust. I thought you just followed the FP instructions and just hooked it up. If it wasn't for cooling threads that I found I would have just hooked it all up like FP said.

Art never gave me any recommendations or put a diagram in the box of parts I ordered from him. I had to call and ask him. Don't get me wrong Art is a great guy and has really hooked me up, but anytime I call to ask him questions he sounds super busy and I always feel like I am bothering him.

There is obviously many right ways to do things, but I like to hear all options then make a decision. Just because Art, Paul, or Chucky says to do something that doesn't mean I am going to do exactly what they told me. They are all great mechanics and know farrrrrr more than I do, but it seems to me they tend to have different ways of doing things which is fine.

Personally I like to hear many different routes to take and either decide on a route to take or combine the different ways of doing things.

Just my .02:biggthumpup:
 
4mm is for the bypass so you keep adequate pressure built up in the line to operate the FCV properly. Anymore than 4mm may bypass to much water. The ID line is only just above 6mm. Superjett is correct about adjusting the rest based on engine temp

That 4mm restrictor goes after the T right?

I've also heard recommendations to put a 1mm restrictor between the FCV and the stinger. Any truth to that? :dunno:

I think Charles is running a restrictor between his FCV and stinger, but Art never told me to do that. Now I know Charles and I have two very far different motors, but would it really matter when you are only talking about cooling the stinger. :dunno:
 
Top Bottom