Fuel Injection Throttle Bodies Discussion
03-17-11, 10:22 AM
#26
Migrant Rotorhead
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In search of cheaper alternatives than all of the above I've talked to a buddy of mine and looked over some old "manfiold swaps" and it looks like an S4/S5 intake might be a viable option because at this point for an n/a build, even buying the Jenvey would be almost pointless because it would only serve to hold a TPS sensor and control throttle since the injectors would be in the stock primary position...hell I could probably plug up my Dellorto and run a speed density setup with no TPS at all but yea, back to this latest round of questions.
Bolting an S3 lower to an S4/5 upper is a no-dice as the bolt patterns seem to be off though the ports appear to line up, has anyone modified either the upper or the S3 lower to allow for a mating?
Bolting an S4/5 lower & upper to an S3 block is do able but there is one issue and one possible problem.
Reason this even came up is my buddy has a few S4 manifolds and I could possibly get an S5 manfiold for a heavily discounted price of zero dollars thus solving a nearly $500 investment in a throttle body, granted I know the S4/5 manifolds probably won't lend themselves to top end as well as something like the DCOE/IDA/Holley Throttle Bodies but $500 buys lot of other parts I need outside of this fuel injection setup.
S4 and S5 intakes, problems and solutions.
Bolting an S3 lower to an S4/5 upper is a no-dice as the bolt patterns seem to be off though the ports appear to line up, has anyone modified either the upper or the S3 lower to allow for a mating?
Bolting an S4/5 lower & upper to an S3 block is do able but there is one issue and one possible problem.
1. Does the emissions port for the center iron correctly align with that of an S4/5 intake? looking at the Mazdatrix catalog with the intake gaskets next to eachother they look correct but this also introduced #2.
2. S3 primary ports seem to be a bit [ok alot] smaller than S4/5 this would cause for an uneven transition from manifold to port. Has anyone actually looked into solving this issue possibly by way of filling the manifold with something viable and sanding/shaping it to correctly match or is it usually left alone.
2. S3 primary ports seem to be a bit [ok alot] smaller than S4/5 this would cause for an uneven transition from manifold to port. Has anyone actually looked into solving this issue possibly by way of filling the manifold with something viable and sanding/shaping it to correctly match or is it usually left alone.
Reason this even came up is my buddy has a few S4 manifolds and I could possibly get an S5 manfiold for a heavily discounted price of zero dollars thus solving a nearly $500 investment in a throttle body, granted I know the S4/5 manifolds probably won't lend themselves to top end as well as something like the DCOE/IDA/Holley Throttle Bodies but $500 buys lot of other parts I need outside of this fuel injection setup.
Lower Manifold Section
76-85 12A *
Part Number: 18111
Price: $190.00
http://www.racingbeat.com/RX7-1975-1...ake/18111.html
A couple guys have built custom intakes (a plate and tubes, essentially) to adapt the 4 throttle bodies from modern sport bikes.
03-17-11, 10:57 AM
#27
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.hell I could probably plug up my Dellorto and run a speed density setup with no TPS at all but yea, back to this latest round of questions.
Bolting an S4/5 lower & upper to an S3 block is do able but there is one issue and one possible problem.[INDENT]1. Does the emissions port for the center iron correctly align with that of an S4/5 intake? looking at the Mazdatrix catalog with the intake gaskets next to eachother they look correct but this also introduced #2.
Bolting an S4/5 lower & upper to an S3 block is do able but there is one issue and one possible problem.[INDENT]1. Does the emissions port for the center iron correctly align with that of an S4/5 intake? looking at the Mazdatrix catalog with the intake gaskets next to eachother they look correct but this also introduced #2.
oh and people put tps's on carbs too, i know a guy who has a tps on his so he can log with the WB
the GSL-SE and S5 have the same emissions hole in the center iron, the S4 uses the holes in the end irons, so the S5 is emissions compatible, the S4 is not. you can do S5 lower and s4 upper
03-17-11, 11:07 AM
#28
Jolly Green Giant
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hot rodders put injectors in fake carbs, basically except for having something that has the same size and bolt pattern you could really use any throttle body.
oh and people put tps's on carbs too, i know a guy who has a tps on his so he can log with the WB
the GSL-SE and S5 have the same emissions hole in the center iron, the S4 uses the holes in the end irons, so the S5 is emissions compatible, the S4 is not. you can do S5 lower and s4 upper
oh and people put tps's on carbs too, i know a guy who has a tps on his so he can log with the WB
the GSL-SE and S5 have the same emissions hole in the center iron, the S4 uses the holes in the end irons, so the S5 is emissions compatible, the S4 is not. you can do S5 lower and s4 upper
hopefully now some of the normal questions with manfiold swaps will be directed to this topic and can be answered.And since I haven't driven my RX-7 in about...4-5 months now this weekend it looks like I'm just gonna pick up a Holley Red or Blue and see if I can get the fuel issue I had before sorted out, I'm in severe withdraw of not being able to drive my car and that was really the only serious issue I was having aside from it needing a serious seafoaming. I'll update as it progresses as I still really want to pursue re-injecting the FB....hopefully I can complete it before life tells me I can't (possibly joining the Navy for a few years).
08-15-11, 02:03 PM
#29
Rotary Enthusiast
I have some twm 50mm's and their ok so far.
I run 4 injectors on mine, would have been nice to just use 2 for less complexity but it works.
Having the injectors mounted up high on the TB instead of the engine location should give your intake manifold and intake charge a cooling effect.
I run 4 injectors on mine, would have been nice to just use 2 for less complexity but it works.
Having the injectors mounted up high on the TB instead of the engine location should give your intake manifold and intake charge a cooling effect.
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