custom manifold pics
09-18-02, 09:54 PM
#51
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Originally posted by turbostreetfighter
sorry for not getting back to y'all sooner, i have been busy with the race car (check out the avatar!!) . ok, the inserts were made of a36 steel and CNC machined to be slightly smaller than the stock port so that they could be ported to match by hand. i did burn out a few turbine wheels when i first tried it and finally ended up using a clipped 'p' trim with a 1.3 on center housing and it worked excellent ang gave phenomenal boost responce and spool up and yes the car have a sharper exhaust note. tuning wise it seemed to work better on the rich side ( around 11.6). EGT's typically ran higher no matter what you did. header wise the best one was 1.75 primaries but it was REAL hard on turbine wheels so i ended up going to 2" and the response was only slightly slower. the best all around turbo that i came up with was the garret T-64 with a 1.03 on center housing and a 15 degree clip on a 'p' trim. i use on center housing because they allow you to use longer header primaries. 'q' trim wheels do not typically last as long and are expensive, you can get the same flow with the clipped 'p' trim.
MWW
sorry for not getting back to y'all sooner, i have been busy with the race car (check out the avatar!!) . ok, the inserts were made of a36 steel and CNC machined to be slightly smaller than the stock port so that they could be ported to match by hand. i did burn out a few turbine wheels when i first tried it and finally ended up using a clipped 'p' trim with a 1.3 on center housing and it worked excellent ang gave phenomenal boost responce and spool up and yes the car have a sharper exhaust note. tuning wise it seemed to work better on the rich side ( around 11.6). EGT's typically ran higher no matter what you did. header wise the best one was 1.75 primaries but it was REAL hard on turbine wheels so i ended up going to 2" and the response was only slightly slower. the best all around turbo that i came up with was the garret T-64 with a 1.03 on center housing and a 15 degree clip on a 'p' trim. i use on center housing because they allow you to use longer header primaries. 'q' trim wheels do not typically last as long and are expensive, you can get the same flow with the clipped 'p' trim.
MWW
Would a similar Turbo with inconnel wheel stand up to the heat and abuse? I believe that innovative offers the inconnel wheel
09-18-02, 10:21 PM
#52
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i have not tried it Greg but it should!!! the standard 'q' trim would 'melt' the tips and bend them back!!! those wheels are about 500.00 so it would be an expensive project!!....ummm ,let me know how it goes!!!
MWW
MWW
09-20-02, 01:50 AM
#53
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Originally posted by rotarygod
Here are my custom machined exhaust sleeves. I went to Marcus Williams in Houston for help on this. I told him how I wanted them and he cut them out. Good job too! These came about after my many conversations with Paul Yaw about exhaust port flow problems. He did this on an aircraft engine using steel tubing with great results and we thought it would be cool to machine a set. Marcus has used several sets now with great results. Basically they are the exact same size as the port openings in the rotor housing but the size and shape remain constant. This results in about 30% more airflow through the same size port! It spools a turbo up much faster than the larger pipe with a port job.
Here are my custom machined exhaust sleeves. I went to Marcus Williams in Houston for help on this. I told him how I wanted them and he cut them out. Good job too! These came about after my many conversations with Paul Yaw about exhaust port flow problems. He did this on an aircraft engine using steel tubing with great results and we thought it would be cool to machine a set. Marcus has used several sets now with great results. Basically they are the exact same size as the port openings in the rotor housing but the size and shape remain constant. This results in about 30% more airflow through the same size port! It spools a turbo up much faster than the larger pipe with a port job.
good work mate, have you made your exhaust manifold up yet?? if so have you got any pics
, i am assuming the shape of the runners will be a similar shape to the exhaust port??? You have got me wanting to pull my exhaust manifold off and make up some sleeves, new manifold etc heheh, i am running a cosmo 13b and currently don't have any exhaust sleeves! how much faster on average would the turbo spool eg, if it started to spool at say 3500rpm would it drop it back to say 3000rpm. Thanks in advancecheers
Lance
09-20-02, 03:21 PM
#54
The difference in spool time is incredible. You may have to change your turbine size depending on what you are running. Farther up the thread turbostreetfighter gives his insight on what works best with them. I had him make the sleeves for me.
09-21-02, 03:30 PM
#56
spoon!
Wow, congrats, this must be one of the most interesting threads I've stumbled across so far. Never put too much thought into how the exhaust ports work before... hmmm.
Wondering how the Yaw flangeything would work at higher flow levels than an ITA motor... moving up to a bridgey for example would require bigger ports for more flow anyway, ne? Just brainstorming, since I doubt I have the cash for custom exhaust sleeves...
Wondering how the Yaw flangeything would work at higher flow levels than an ITA motor... moving up to a bridgey for example would require bigger ports for more flow anyway, ne? Just brainstorming, since I doubt I have the cash for custom exhaust sleeves...
09-24-02, 06:00 AM
#59
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Interesting - I was always amazed how well my old 10A PP went - The rotor housings were R-100 ones which had an oval exhaust port which was very similar to the sleeves pictured. These housings were pre 3 holed style of the RX3. That PP had amazing torque and power, used to give many 13B jport and 13Bpp `s a run - just didnt have the top speed 
09-24-02, 08:42 AM
#60
Lives on the Forum
looks good
i have a question though, what is benifit of having TB face the front of car as opposed being Straight off the plenum? i notice some people do this and was wondering why. able (flaco) uses it in both his cars.
i have a question though, what is benifit of having TB face the front of car as opposed being Straight off the plenum? i notice some people do this and was wondering why. able (flaco) uses it in both his cars.
09-24-02, 12:14 PM
#61
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Originally posted by rxrotary2_7
looks good
i have a question though, what is benifit of having TB face the front of car as opposed being Straight off the plenum? i notice some people do this and was wondering why. able (flaco) uses it in both his cars.
looks good
i have a question though, what is benifit of having TB face the front of car as opposed being Straight off the plenum? i notice some people do this and was wondering why. able (flaco) uses it in both his cars.
09-24-02, 03:35 PM
#62
spoon!
Originally posted by rotarygod
I would think that anything that helps exhaust flow would only work better in any other circumstance ITA, bridge or otherwise. They aren't all that expensive. Not for the gains you get.
I would think that anything that helps exhaust flow would only work better in any other circumstance ITA, bridge or otherwise. They aren't all that expensive. Not for the gains you get.
Which is what banzaitoyota asked too, but I feel the need to add my query. And my apologies if this has been answered before.
09-24-02, 04:32 PM
#63
The only reason I have my throttlebody facing forward is because it wouldn't fit in line. My blow off valve is mounted on the tb and hangs below it. It would have hit the top of the motor.
There actually was a benefit from this location though. First of all it does not add to the overall plenum volume. I know this is contrary to logical thinking. The plenum is the area that the runners terminate into. The intake pipe is also a runner that dumps into the plenum so its volume is not used to calculate total area. At idle the plenum isn't doing much and we don't try to tune it to this application anyways. When the throttle plates are opened the air simply passes the plate and enters the plenum. Even at full throttle how does the incoming air know where the throttle plate is if any? It doesn't. Take a look at a diesel engine sometime. They still have plenum chambers but do not have any throttle plates since diesels are always receiving a full charge of air. Anyone who understands how a diesel works will realize this. To all the othes this may sound confusing.
The other benefit to this location is that since the throttle plate is so far away, the air turbulence caused by the plate is completely gone by the time it gets to the plenum. This helps ensure that air is more evenly distributed throughout the plenum and at full throttle acts as if there were no plate there at all. If the throttle plate were right in front of the chamber then there would be more turbulence throughout the plenum at partial throtle levels and could affect air distribution.
I don't know if Marcus can still make them so I don't have a price. I need to find out if he can and if not then I need to find another source that won't rape me on pricing.
There actually was a benefit from this location though. First of all it does not add to the overall plenum volume. I know this is contrary to logical thinking. The plenum is the area that the runners terminate into. The intake pipe is also a runner that dumps into the plenum so its volume is not used to calculate total area. At idle the plenum isn't doing much and we don't try to tune it to this application anyways. When the throttle plates are opened the air simply passes the plate and enters the plenum. Even at full throttle how does the incoming air know where the throttle plate is if any? It doesn't. Take a look at a diesel engine sometime. They still have plenum chambers but do not have any throttle plates since diesels are always receiving a full charge of air. Anyone who understands how a diesel works will realize this. To all the othes this may sound confusing.
The other benefit to this location is that since the throttle plate is so far away, the air turbulence caused by the plate is completely gone by the time it gets to the plenum. This helps ensure that air is more evenly distributed throughout the plenum and at full throttle acts as if there were no plate there at all. If the throttle plate were right in front of the chamber then there would be more turbulence throughout the plenum at partial throtle levels and could affect air distribution.
I don't know if Marcus can still make them so I don't have a price. I need to find out if he can and if not then I need to find another source that won't rape me on pricing.
Last edited by rotarygod; 09-24-02 at 04:37 PM.
09-24-02, 04:51 PM
#64
spoon!
Hm. Is the plenum size/design as much of a critical factor for an NA car? I ask because for the most part, it seems to only come up in turbo applications and I'm wondering if I'm missing something.
That feels like a dumb question... but I haven't yet reached a point in college where I'm learning stuff like this, and don't have any previous experience in intake design. And this discussion's going too, so...
Apologies in advance if I'm asking something bonheadedly stupid.
That feels like a dumb question... but I haven't yet reached a point in college where I'm learning stuff like this, and don't have any previous experience in intake design. And this discussion's going too, so...
Apologies in advance if I'm asking something bonheadedly stupid.
09-24-02, 06:15 PM
#65
Most people think that intake tuning is only critical on n/a cars. So yes is the answer to your question. The truth is that plenum size, runner diameter, length, etc. all play the same important roles regardless of whether or not the engine is n/a or turbocharged. Centrifugal superchargers apply as well. However positive displacement superchargers do not need to rely on these factors since there is always positive manifold pressure. The tuning effects in this case are minimal.
09-24-02, 06:37 PM
#66
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yeah plenum design will have an affect on an na car. you just don't get as much of a hp difference w/ changes in airflow w/ na cars so the differences aren't as noticeable. the stock im can push enough air for a lot more hp, so people usually stick w/ stock until they've done a bunch of other mods like headers, porting, etc. but, if you're gonna have an intake manifold made why not make it to the proper volume.
rotarygod, you have an interesting point on that volume thing, but i have to kinda disagree w/ you. though that extra pipe isn't exactly the plenum itself, it is extra volume that should be accounted for. i'm not saying that the plenum should be made smaller by the exact volume that that pipe takes up, but there is definitely a dynamic there that comes into play. i think everything btwn the tb and the intake ports should be taken into account when designing your intake including the plenum, the intake runners, and any extra pipes. but that's just my opinion.
rotarygod, you have an interesting point on that volume thing, but i have to kinda disagree w/ you. though that extra pipe isn't exactly the plenum itself, it is extra volume that should be accounted for. i'm not saying that the plenum should be made smaller by the exact volume that that pipe takes up, but there is definitely a dynamic there that comes into play. i think everything btwn the tb and the intake ports should be taken into account when designing your intake including the plenum, the intake runners, and any extra pipes. but that's just my opinion.
09-24-02, 06:43 PM
#67
spoon!
Oh! Okay, I'm dense... I never associated plenum size with intake tuning... had a nasty habit of assuming IR setups.
Hrrrrrm... got some math to do now. Thanks a lot.
Hrrrrrm... got some math to do now. Thanks a lot.
09-24-02, 06:54 PM
#68
spoon!
Originally posted by fdracer
yeah plenum design will have an affect on an na car. you just don't get as much of a hp difference w/ changes in airflow w/ na cars so the differences aren't as noticeable. the stock im can push enough air for a lot more hp, so people usually stick w/ stock until they've done a bunch of other mods like headers, porting, etc. but, if you're gonna have an intake manifold made why not make it to the proper volume.
yeah plenum design will have an affect on an na car. you just don't get as much of a hp difference w/ changes in airflow w/ na cars so the differences aren't as noticeable. the stock im can push enough air for a lot more hp, so people usually stick w/ stock until they've done a bunch of other mods like headers, porting, etc. but, if you're gonna have an intake manifold made why not make it to the proper volume.
The reason I'm trying to figure out a custom IM is because I want to move over to a homegrown EFI system and cut another pair of holes in the housings. 
Yeah, I have some idea what I'm getting myself into trying to design a PPort secondary engine running a homebrew EFI system and IM. It is, to a large extent, a science experiment more than anything that's going to be going into a car. But then again, there's also the idea of using it as my senior project in a few years lurking in my mind...
09-25-02, 08:24 PM
#69
fdracer I hear what you are saying about everything after the tb playing an important role. Location of the tb just doesn't matter. The pipe it is on has no effect on the plenum size in anyway. You can put the tb before the turbo if you wanted. Its been done before. Not sure about how much lag time there would be but it still doesn't effect the intake system tuning.
Kenku if you want a pp secondary engine I hope you don't want a muffler. It has to be very free flowing and will be quite loud. Not that I care of course The way to do it is to use the outer housing ports (not the inner) as your primaries since they flow better. Use a smaller pp intake. You don't want it to be a full size 2" if you have the other ports working as well. Just use a vacuum secondary Holley carb. Have the secondaries open at a higher RPM so you can still have some decent low end and a fair idle. Won't be perfect but should work great. Paul Yaw has actually toyed with the idea in his head but never built it. If you wanted to use efi then I would find a way to use 2 different sets of throttle plates so you can open the pp later.
Kenku if you want a pp secondary engine I hope you don't want a muffler. It has to be very free flowing and will be quite loud. Not that I care of course
The way to do it is to use the outer housing ports (not the inner) as your primaries since they flow better. Use a smaller pp intake. You don't want it to be a full size 2" if you have the other ports working as well. Just use a vacuum secondary Holley carb. Have the secondaries open at a higher RPM so you can still have some decent low end and a fair idle. Won't be perfect but should work great. Paul Yaw has actually toyed with the idea in his head but never built it. If you wanted to use efi then I would find a way to use 2 different sets of throttle plates so you can open the pp later.
09-25-02, 08:54 PM
#70
spoon!
Finding a way to use 2 different TBs was my idea *EXACTLY*. Unfortunately, it also means coming up with a scratch-built EFI computer, but hey... part of the fun, ne? I'm waiting for a response from some people on that...
... my plan was to have all four original ports, though unmodified, with an intake tuned for around 4k RPM. A ways after that (5-6k?) the PPort TB would start to be opened by the ECU... either by a straight RPM based figure, or by using MAP and throttle position on the primaries to figure out when it's hitting breathing limits. I'd prefer the second, but I *know* the first is possible. Ideally, I'd also like the system to regulate how fast it's opening them... taking the MAP reading and figuring out how far to crack the valve to keep the flow velocity up. Or, again, just have it figure out how far to open it based on RPM.
Okay. So, I think I've more or less ruled out any commercially available ECU within my price range... which leaves me to solder one together myself, or talk to some people who're experimenting with doing the same. Right. That's the electronics part.
The fluid dynamics part gets even more interesting, IMO anyway. But basicially it comes down to port size and timing... and I don't know enough right at the moment to say more specificially than "yeah, I'm going to be wanting to use something smaller than the MFR ports". Exhaust ports... are going to take even more thought. The rest of the system... well... muffler's such a broad term...
Anyway, I may be getting overly ambitious here. Wouldn't be the first time. I will say that this has given me more and more incentive to take as many classes as I can so I can get to computational fluid dynamics stuffle. Or I might have to start teaching myself ahead of time...
... my plan was to have all four original ports, though unmodified, with an intake tuned for around 4k RPM. A ways after that (5-6k?) the PPort TB would start to be opened by the ECU... either by a straight RPM based figure, or by using MAP and throttle position on the primaries to figure out when it's hitting breathing limits. I'd prefer the second, but I *know* the first is possible. Ideally, I'd also like the system to regulate how fast it's opening them... taking the MAP reading and figuring out how far to crack the valve to keep the flow velocity up. Or, again, just have it figure out how far to open it based on RPM.
Okay. So, I think I've more or less ruled out any commercially available ECU within my price range... which leaves me to solder one together myself, or talk to some people who're experimenting with doing the same. Right. That's the electronics part.
The fluid dynamics part gets even more interesting, IMO anyway. But basicially it comes down to port size and timing... and I don't know enough right at the moment to say more specificially than "yeah, I'm going to be wanting to use something smaller than the MFR ports". Exhaust ports... are going to take even more thought. The rest of the system... well... muffler's such a broad term...
Anyway, I may be getting overly ambitious here. Wouldn't be the first time. I will say that this has given me more and more incentive to take as many classes as I can so I can get to computational fluid dynamics stuffle. Or I might have to start teaching myself ahead of time...
09-25-02, 09:01 PM
#71
You could make one manifold with two throttle bodies work off of an existing computer system easily. Use a larger primary throttle body that feeds a plenum. All of your runners will intersect here including the pp. The difference is that you would put a 2nd throttle plate going to the pp. You could actuate it off of a vacuum signal. You could probably rig up a way for the factory 6 port vacuum actuator to be modified to open and close a throttle plate. If you wanted to have some real fun put another plate to the standard side ports. Run both secondary throttle plates off of an electric actuator. At a certain rpm one will open the other will close. Use an RPM switch for this. The primary throttle plate still ultimately controls how much air enters the engine. Just brainstorming now. It would be one hell of a project.
09-25-02, 09:39 PM
#72
spoon!
Oh *HEY* now. It never occured to me that I could close off the side ports and have it act like a full PPort... hm.
The question comes though, where to put the injectors? I mean, is it possible to have a standard aftermarket EFI system completely shut off one set of injectors and start up another? And... hm. The changeover could get tricky, even if it were possible... though... doh. I'm dumb... blend the port closing / port opening and the fuel flow so it's not a sudden change...
... that would really really be a lot easier to get working, EFI-wise... I seem to have a bit of a tendency to let things get over-complicated.
One of the reasons I'd like the PPort switchover to be electronic is the fact that it seems that it would be nice to be able to shut them *off* sometimes... things like freeway cruising at legal speeds. Though come to think of it, having an RPM driven system would accomplish the same thing.
Hrrrrm.
The question comes though, where to put the injectors? I mean, is it possible to have a standard aftermarket EFI system completely shut off one set of injectors and start up another? And... hm. The changeover could get tricky, even if it were possible... though... doh. I'm dumb... blend the port closing / port opening and the fuel flow so it's not a sudden change...
... that would really really be a lot easier to get working, EFI-wise... I seem to have a bit of a tendency to let things get over-complicated.
One of the reasons I'd like the PPort switchover to be electronic is the fact that it seems that it would be nice to be able to shut them *off* sometimes... things like freeway cruising at legal speeds. Though come to think of it, having an RPM driven system would accomplish the same thing.
Hrrrrm.
09-26-02, 12:04 AM
#75
spoon!
Originally posted by Node
oh yea, i think scoots secondary pports are 40mm (about 1.4") but im not positive on that, maybe 30mm, but 40 sounds right
oh yea, i think scoots secondary pports are 40mm (about 1.4") but im not positive on that, maybe 30mm, but 40 sounds right
*shrug* I've never said this has not all been thought of before. I just have searched and not been able to find technical discussions that answered what I wanted to know.
... so yeah. I'd greatly love any RL data about attempts at this. I've been able to find none other than the Scoot thing (which, as I said, is turbo).