The Definitive "VVT swap into 90-97 chassis" Megathread.
05-24-2015, 07:28 PM
#161
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Just fielded a tech question on this topic and the answer is worth adding to this thread.
e: He is using a USDM 01-05 manifold with the VTCS system.
I just encountered this myself about a month ago. I think there are multiple versions of the '99 fuel rail. The easy way to deal with this problem is to remove the VTCS butterflies, slide the shaft out of the manifold, and then drill/tap/plug the hole in the end, or have a welder weld up the end. You don't have to worry about the holes between the cylinders. The little stud that locates the VTC S butterfly pivot will pull out of the manifold with a pair of pliers and some effort. That will give you the clearance you need to run the '99 rail and your 1.6L FPR.
e: He is using a USDM 01-05 manifold with the VTCS system.
Originally Posted by Savington
Originally Posted by amaff
Using the 99 fuel rail, the feed line interferes with the VICS opening on the manifold, and the 1.6 FPR attempts to occupy the same airspace as the top half of the manifold.
Last edited by Savington; 05-24-2015 at 08:19 PM.
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05-27-2015, 11:29 AM
#165
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Just fielded a tech question on this topic and the answer is worth adding to this thread.
e: He is using a USDM 01-05 manifold with the VTCS system.
I just encountered this myself about a month ago. I think there are multiple versions of the '99 fuel rail. The easy way to deal with this problem is to remove the VTCS butterflies, slide the shaft out of the manifold, and then drill/tap/plug the hole in the end, or have a welder weld up the end. You don't have to worry about the holes between the cylinders. The little stud that locates the VTC S butterfly pivot will pull out of the manifold with a pair of pliers and some effort. That will give you the clearance you need to run the '99 rail and your 1.6L FPR.
e: He is using a USDM 01-05 manifold with the VTCS system.
Originally Posted by Savington
Originally Posted by amaff
Using the 99 fuel rail, the feed line interferes with the VICS opening on the manifold, and the 1.6 FPR attempts to occupy the same airspace as the top half of the manifold.
I just want to also confirm that there are 2 different fuel rails for the 99 miata. I encountered this a few years ago and went out to PanicMotorsports and looked at multiple 99's Steve had in stock. Some of my older posts scattered around show the exact differences.
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05-27-2015, 12:00 PM
#166
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I just saw this. I would assume it's because for a plug and play ECU, the pin on the ECU connector is a tach input, the ignitor generates the signal, though I don't know why the ECU would care other than to verify the ignitor is actually working.
The ignitors on the VVT coils don't generate this signal, so the responsibility for it falls to the ECU, which is now outputting instead of receiving, different circuitry behind there. It would be handy though if he had a jumper on the board that would let you switch on an output on that pin though,and I doubt it's doing anything when it's connected to a non-swapped 90-93 chassis.
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05-28-2015, 10:34 PM
#167
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I just saw this. I would assume it's because for a plug and play ECU, the pin on the ECU connector is a tach input, the ignitor generates the signal, though I don't know why the ECU would care other than to verify the ignitor is actually working.
The ignitors on the VVT coils don't generate this signal, so the responsibility for it falls to the ECU, which is now outputting instead of receiving, different circuitry behind there. It would be handy though if he had a jumper on the board that would let you switch on an output on that pin though,and I doubt it's doing anything when it's connected to a non-swapped 90-93 chassis.
The ignitors on the VVT coils don't generate this signal, so the responsibility for it falls to the ECU, which is now outputting instead of receiving, different circuitry behind there. It would be handy though if he had a jumper on the board that would let you switch on an output on that pin though,and I doubt it's doing anything when it's connected to a non-swapped 90-93 chassis.
In any case, my car is running, most things have been sorted out. Playing with the VE tables to get everything right, and still on Reverent's base map AFR targets and timing. I'm running the entire 95 intake with the exception of the top half of the 02 airbox, so I had a place to put the IAT. It's not ideal, but it's what I have for now. Thanks everyone in this thread for the help! I'll be helping a buddy do this swap in his car, so I'll definitely pass it forward.
Last edited by Morello; 05-30-2015 at 04:48 PM.
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06-08-2015, 10:54 PM
#168
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<p>Would it be possible to use the 01-05 fuel rail with an aftermarket fuel pressure regulator and some sort of adapter instead of the stock FPR (disclaimer: I don't have a full understanding of the fuel flow on the vvt motor.)</p>
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06-08-2015, 11:09 PM
#170
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I would venture to say you can use the 99-05 rail with an aftermarket regulator, provided it was mounted somewhere other than on the rail itself. Your NA6 chassis has a return, so its just a matter of plumping the OEM feed from the tank to the aftermarket regulator, plumbing the return from the regulator into the OEM return line, and plumbing the "out to engine" to the 99-05 rail. Adapters exist for all of these connections to the factory hardlines.
Use of an aftermarket regulator would complicated things as compared to sticking your NA6 regulator on a 99 rail, but it would also give you the ability to adjust your fuel pressure as you see fit.
You are talking about swapping a BP6D into your NA6 chassis and running an MS, correct?
Use of an aftermarket regulator would complicated things as compared to sticking your NA6 regulator on a 99 rail, but it would also give you the ability to adjust your fuel pressure as you see fit.
You are talking about swapping a BP6D into your NA6 chassis and running an MS, correct?
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06-09-2015, 05:00 AM
#173
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Aside from the added effort I don't see a problem with you doing that. There's a "fake FPR" (suppose it acts like a load balancer) on the end of the rail and it's detachable, the only reason I see the rail is not used, is the direction that this "fake FPR" is facing.
So if you can connect an external FPR to it, it should work no problem!
So if you can connect an external FPR to it, it should work no problem!
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06-09-2015, 10:24 AM
#174
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The OE FPR is overwhelmed by large fuel pumps, but you don't need anything beyond the stock pump to feed a 140whp VVT swap. If you were adding FI to a VVT swap and needed to run something like a DW300, then yes, you might be able to use the 01-05 rail with an FPR adapter and something like a Fuelab adjustable regulator mounted elsewhere in the car.
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06-09-2015, 02:31 PM
#175
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<p>I plan on an FI VVT at some point, hence my question, if I can put together a setup using the 01-05 fuel rail it saves me money in the long run.</p><p>So something like this plumbed to a fuelab afpr, then to the return line?</p><p><img src="http://cimg3.ibsrv.net/gimg/www.miataturbo.net-vbulletin/600x600/80-fuel_rail_delivery_adapter_regulator_mazda_rx_7_rx 7_fd3s_mx5_mx_5_miata_na_nb_nc_autobahn88_ft061_00 3_ef82047e7d166414b8a5dc54908d42c36f62c5a9.jpg" title="" /><br /><br /> </p>
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06-18-2015, 04:46 PM
#176
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Swap is finally done and the car is purring as usual, apart from the fact that I still don't have VVT control, idle control, TPS and RPM. I'll get there.
However, a question which may or not be relevant to the subject of these swaps. Is the oil pressure with the BP-Z3 engine expected to be any different from the B6-ZE?
My gauge is a little bit above 6 bar when I start the car from cold, whereas with the B6 it used to be around 5 maybe. Maybe this is to be expected, or maybe I've knackered the sensor. Any thoughts?
However, a question which may or not be relevant to the subject of these swaps. Is the oil pressure with the BP-Z3 engine expected to be any different from the B6-ZE?
My gauge is a little bit above 6 bar when I start the car from cold, whereas with the B6 it used to be around 5 maybe. Maybe this is to be expected, or maybe I've knackered the sensor. Any thoughts?
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06-18-2015, 05:55 PM
#177
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The pump is different and there are additional oil system components, so a change in pressure isn't unreasonable. I put little weight in small differences in cold pressure. As long as hot pressure is where it needs to be, you're OK.
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06-19-2015, 03:57 PM
#180
Interesting. Mine is generally at 20-25 psi at idle; 40-45 psi while cruising around; and always 40psi while at the track being horse beat.
I noticed a ~5psi drop across the board when going to synthetic oil after break-in.
All numbers are with 10w30 oil.
Bottom end clearances were all ~1.8 thousandths.
No issues in 3k miles with 3 track days.
I should also note that my oil pressure sensor has been relocated to the firewall. Not sure if that messes with my numbers, but it wouldn't surprise me.
I noticed a ~5psi drop across the board when going to synthetic oil after break-in.
All numbers are with 10w30 oil.
Bottom end clearances were all ~1.8 thousandths.
No issues in 3k miles with 3 track days.
I should also note that my oil pressure sensor has been relocated to the firewall. Not sure if that messes with my numbers, but it wouldn't surprise me.
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