Q About how our Wastegate operates
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Q About how our Wastegate operates
I was talking to someone I know who owns a Ford Tbird Turbo coupe and he was telling me about the bypass valve around the wastegate that he installed to increase boost. (just a hose that goes from one side to the other) He thought that I couldn't increase my boost by freeing up the exhaust because the wastegate is set at a certain level and it should always open at that level. Obviously he's wrong, but I couldn't explain to him why.
Could someone explain? Also, what's the deal with the bypass hose he installed, why doesn't anyone do that on RX-7s?
Could someone explain? Also, what's the deal with the bypass hose he installed, why doesn't anyone do that on RX-7s?
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Either he’s explained it wrong or you’ve misunderstood him. You don’t bypass anything to raise boost, you bleed some of the pressure out of the wastegate actuator hose. this lowers the pressure seen by the actuator so it opens later, raising boost. An inline pressure-reducing valve can do the same thing.
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If the wastegate was large enough, it would not have any problem bypassing at 10psi if you have a 10psi spring in it.  The "problem" with the stock FC turbo is that once the intake/exhaust is opened up, exhaust flow is so great, it overcomes the very small wastegate orifice.  This is how you get higher boost with better intake/exhaust efficiency.
-Ted
-Ted
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hey ted did you read the sport compact car where they put the turbo on the matrix? they had a problem with boost creep so they built a bulge on the downpipe/copressor housing so the wastegate flow has a more gradual entrance into the regular exhaust flow. do you think something like that would help the fc?
mike
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Originally posted by j9fd3s
hey ted did you read the sport compact car where they put the turbo on the matrix? they had a problem with boost creep so they built a bulge on the downpipe/copressor housing so the wastegate flow has a more gradual entrance into the regular exhaust flow. do you think something like that would help the fc?
mike
hey ted did you read the sport compact car where they put the turbo on the matrix? they had a problem with boost creep so they built a bulge on the downpipe/copressor housing so the wastegate flow has a more gradual entrance into the regular exhaust flow. do you think something like that would help the fc?
mike
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Originally posted by j9fd3s
...they built a bulge on the downpipe/copressor housing so the wastegate flow has a more gradual entrance into the regular exhaust flow. do you think something like that would help the fc?
...they built a bulge on the downpipe/copressor housing so the wastegate flow has a more gradual entrance into the regular exhaust flow. do you think something like that would help the fc?
When I do my downpipe, I plan to replace the backplate of the turbine housing with a custom cut flange so the downpipe can be expanded up to cover the whole turbine wastegate area. If you have alook at his photo of a WRX exhaust you'll see what I mean. We’ll see what happens.
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ok I suck and can't remember passwords... for those that know it should be in the rxtech folder on yahoo GW_86drag/ex_coll.jpg if someone could get it LOL...
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Originally posted by RETed
If the wastegate was large enough, it would not have any problem bypassing at 10psi if you have a 10psi spring in it.  The "problem" with the stock FC turbo is that once the intake/exhaust is opened up, exhaust flow is so great, it overcomes the very small wastegate orifice.  This is how you get higher boost with better intake/exhaust efficiency.
-Ted
If the wastegate was large enough, it would not have any problem bypassing at 10psi if you have a 10psi spring in it.  The "problem" with the stock FC turbo is that once the intake/exhaust is opened up, exhaust flow is so great, it overcomes the very small wastegate orifice.  This is how you get higher boost with better intake/exhaust efficiency.
-Ted
NZ : From what little I was told about the ford 2.4L turbo, it seems to be more like a S5 turbo than a S4 in that it's orifice is larger. He is running 18PSI, stock was somthing like 12PSI. He seemed to have a line that would allow gas destine for the wastegate, to be used to power the compressor. I'm probably not using the proper termanology that would allow you to understand what I'm trying to say...
Thanks for replies.
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Originally posted by Snrub
He seemed to have a line that would allow gas destine for the wastegate, to be used to power the compressor.
He seemed to have a line that would allow gas destine for the wastegate, to be used to power the compressor.
Have a read of this article and see if you can work out what he’s done.
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Originally posted by j9fd3s
hey ted did you read the sport compact car where they put the turbo on the matrix?
hey ted did you read the sport compact car where they put the turbo on the matrix?
they had a problem with boost creep so they built a bulge on the downpipe/copressor housing so the wastegate flow has a more gradual entrance into the regular exhaust flow. do you think something like that would help the fc?
It would've been a lot cheaper to go the route tims did by cutting a hole in the stock turbo backing plate and slapping on a big *** wastegate.  The prices would've been similar, and the boost control more superior with the aftermarket WG retrofit.
-Ted
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Originally posted by RETed
Our designed would've replaced the existing backing plate on the turbo and run a funky discharge into the downpipe. This would require a totally new downpipe or a two-piece unit.
Our designed would've replaced the existing backing plate on the turbo and run a funky discharge into the downpipe. This would require a totally new downpipe or a two-piece unit.
Cost was pretty damn high, as the turbo backing plate is like 1/2" thick! Cost to rebend the downpipe section would've added more to everything, and when we did a cost analysis, you're looking at a $500 piece of pipe!
One way to do it is to cut a section out of the side of the (say) 3” pipe, and using another cut sections of 3” pipe weld then all together to cover both turbine and wastegate port. Sounds rough, but careful measuring, cutting, bending and welding will make a nicely shaped piece.
BTW, how come quoting one of your posts always results in lots of “& n b s p” text strings scattered through it. What weird computer software are you using?
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Originally posted by Scott 89t2
ok I suck and can't remember passwords... for those that know it should be in the rxtech folder on yahoo GW_86drag/ex_coll.jpg if someone could get it LOL...
ok I suck and can't remember passwords... for those that know it should be in the rxtech folder on yahoo GW_86drag/ex_coll.jpg if someone could get it LOL...
come on someone post my dam pic! ted must be on rxtech.
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Originally posted by NZConvertible
BTW, how come quoting one of your posts always results in lots of “& n b s p” text strings scattered through it. What weird computer software are you using?
BTW, how come quoting one of your posts always results in lots of “& n b s p” text strings scattered through it. What weird computer software are you using?
-Ted
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*gasp* you're missing like 10 e-mails a day ted!!
fine I just e-mailed the list to get someone to send me the pics LOL.. but they are just what you guys are talking about but done to an FC.
fine I just e-mailed the list to get someone to send me the pics LOL.. but they are just what you guys are talking about but done to an FC.
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Originally posted by RETed
did by cutting a hole in the stock turbo backing plate and slapping on a big *** wastegate.
-Ted
did by cutting a hole in the stock turbo backing plate and slapping on a big *** wastegate.
-Ted
Hmmm...I was thinking about trying this out. Basically just taking the exhaust housing, welding the stock wastegate shut and then cutting a section out of the back plate and welding a wastegate to the outside...or wherever fitting will allow...external wastegate on a stock FC exhaust housing...How interesting!
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Originally posted by jspecracer7
...welding the stock wastegate shut and then cutting a section out of the back plate and welding a wastegate to the outside...
...welding the stock wastegate shut and then cutting a section out of the back plate and welding a wastegate to the outside...
What I think you mean is remove the flap and enlarge the port as much as possible. You’d then need to completely separate the turbine exit and the old wastegate port from each other.
I’ve seen pics of this done on this forum before. As long as you did all the work yourself, this could be a good budget upgrade for the stock turbo.
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Originally posted by NZConvertible
So how would the exhaust gases bypass the turbine if the port is welded shut?!
What I think you mean is remove the flap and enlarge the port as much as possible. You’d then need to completely separate the turbine exit and the old wastegate port from each other.
I’ve seen pics of this done on this forum before. As long as you did all the work yourself, this could be a good budget upgrade for the stock turbo.
So how would the exhaust gases bypass the turbine if the port is welded shut?!
What I think you mean is remove the flap and enlarge the port as much as possible. You’d then need to completely separate the turbine exit and the old wastegate port from each other.
I’ve seen pics of this done on this forum before. As long as you did all the work yourself, this could be a good budget upgrade for the stock turbo.
I didn't even "visualize" what I was typing...now that you've mentioned it...did I mention I was stupid
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Ive got an interesting question. I know the wastegate is built into the turbo (ours anyway) and how it works. However, im wondering, what is the flapper in the manifold for, and how does it work?
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Originally posted by TonyTurboII
...what is the flapper in the manifold for, and how does it work?
...what is the flapper in the manifold for, and how does it work?
While this system sounds like a good idea (I think it is), Mazda obviously didn't think so, because the redesigned 89-91 turbo didn't use it.
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if you drive a twin scroll car back to back with an 89+, the 89+ has less lag. its a good idea, one that leads right to the twin turbos on the fd, but i dont think is very effective (imo). actually the most annoing thing is when the car suddenly gets louder when cruising
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