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BlitzWing
01-20-2014, 12:18 PM
I'm looking for clarification on what I need and some things I've been told before I really make a move on this build so just tell me if anything I've listed is wrong.


So I know I will need an...

. ECU. I've jumped the gun on this and I've ordered a MS2PNP since its got a MAP sensor built in. To install it (assuming its got a tune loaded) I plug it in and I just hook up the vacuum line to a vacuum source and jobs done? (I will be leaving the fine tuning to someone else)

. ITB's. I'm looking at the Jenvey kit since it comes with the throttle bodies, fuel rail, linkage, manifold and air horns. In other words I just need to add the injectors and bolt it on.

. An intake gasket. This one just seems to be more of a guess then something I've been told. since the car is 19 years old I'm guessing the factory gasket is not really going to be reusable. I've heard phenolic gaskets are a good idea to stop heat bleeding into the intake manifold but is it worth the time?

. Fuel lines. Since the Jenvey kit comes with a fuel rail with 2 inputs I'd need to get some hoses to connect it to the factory fuel lines. I'm not too clued in on what the types of connections are for fuel lines but I cant really see it being a problem so long as their are no leaks.

. A vacuum block and hoses. From what I gather I'd need one hole for the break booster, Map sensor, 1 for each throttle body and 1 for a fuel pressure regulator. I plan to delete the charcoal canister and I'm going to run a catch can from the PCV and the other exit on the cam cover.

. IAT I've got a GM sensor in the kit I've ordered. But what I find funny is that it only needs to be near the intakes it does not necessarily need to be in the air flow path?

. Fuel pressure regulator is this needed? I can see why it might be a good idea but is it mandatory?

. Throttle position sensor. I've been told its possible to do it without and its possible to get a better idle with it gone but that seems odd to me. Also is it possible to recycle the one from the 1.8 TB?

. Filters of some sort. I don't want to mess with the venturi effect so I'm thinking sausage filter?


Now for things I dont get.

. Will I need to custom make a throttle cable? keep in mind I'm thinking of going for the Jenveys right now not the toyota's

. Wideband O2 sensor yes/No?

. the coolent line that runs to the ISC valve do I just patch that to the pipe coming from the thermostat housing?

kung fu jesus
02-25-2014, 08:42 AM
I don't have any firsthand experience with ITBs. The issues I have read about comes in the tuning or driveability. It's not that they are unreliable, it just requires a lot of specific troubleshooting to make them happy.

riefdaddy
02-26-2014, 01:19 PM
I've looked at ITBs and read on the subject, but I couldn't justify the price. I've read articles both ways on the throttle cable, some say yes and others say they were able to modify the existing one to work. I can't recall on the other two questions and I think a part of the answer lies in the kit you plan to install. Probably the best place to get the answers is from the manufacturer of the kit. Here is a link to Emerald Performance's Jenvey install and I'd guess you could ask them for information on your outstanding questions as they are a Jenvey dealer. https://www.facebook.com/media/set/?set=a.10150745589731352.461021.194777241351&type=1

BlitzWing
02-26-2014, 02:39 PM
I must admit the more I read into it the more I'm tempted to go with a super charger kit. I can reuse my ECU and I wont have to remove the intake. I'd just need to think about a wide band o2 sensor, some slim fans and maybe a coolent reroute as I'm guessing my current rad is a bit too big to allow one to fit normally.

However dat sound. As for price since Jenvey are based in the UK a good chunk of the cost goes down. So their whole set up shipped is around £700 I'd just need to think about tuning, the fuel system and hooking up the vacuum lines. all in all I think I can get it all done under £1500 minus tuning/dyno time.

thanks for the FB link if anyone else has a really detailed build thread I'd love to take a peak. Most I can find seem to be mostly finished builds and threads like this.

kung fu jesus
02-26-2014, 02:45 PM
I know a few people who have done them. EVdog was/is in the middle of his, but I don't think he has been posting updates. True the sound is intoxicating, but sometimes I read about the nagging issues with them and I wonder if it's worth it.

Pfunk
02-26-2014, 03:14 PM
I did a fairly robust DD n/a build and was warned off ITBs by well-known shops on both sides of the Pacific, one of which had their own ITB kits!

BlitzWing
02-26-2014, 04:33 PM
hmmm fair point. Well I know that I now need a wideband now but luckily the bung location on the Fujitsubo manifold is over 18" from the exhaust port if I've measured it correctly so no welding needed :) I'm looking at the AEM UEGO as its well priced and easy to get plus I know of a few people who have used them.

Am I right in thinking the wideband and narrowband have the same fitting? I really don't want to cut up my Fuji if I end up wanting to sell it someday.

kung fu jesus
02-26-2014, 04:53 PM
Yes, same fitting.

BlitzWing
03-04-2014, 06:14 AM
awesome thanks. well my wide band should be with me next week its an AEM uego. I picked it since it seems easy to wire in and set it with minimal thinking on my part. I'm now looking at the AEM FPR to go with it. After reading the epic build thread for Skrat I have a feeling my only issues will be if the jenvey kit comes pre-tapped for the vacuum lines and possible clearance with the alternator bracket but rather then chopping at the alternator bracket I might try and find an L peace to put the vacuum line at a 45 or 90 degree angle to give it clearance.

miata2fast
03-05-2014, 08:13 PM
I didn't build an ITB set up, but instead went with dual Weber carbs. So I can help you with the throttle cable.

Typically you can adjust how far the end of the cable is attached at the throttle side. However, sometimes the amount of throw the cable needs before it maxes out will be different. To compensate for a shorter throw, there is an adjustment on how far the gas pedal travels. The adjustment is located on the upper end of the pedal. You want the pedal to hit the stopper at the same time the throttle body is in the full open position. If it isn't, you can damage components on the ITBs or the throttle cable itself.

It helps to have a helper inspect the throttle side of the cable while you adjust the pedal side. It is not that big of a deal.

The hardest part of the whole deal in some cases (at least for me) is to be sure all throttles are opening and closing at the same angle as the rest of the throttle bodies. Some systems are better than others as far as how much work it takes to get it adjusted and working properly.

Dmn2258
03-06-2014, 12:04 AM
I've had ITB's in my NA for awhile now. I might add that it's my DD. Certainly hasn't been perfected tuning wise with the ITB's.......I wasted my money on a shitty tune. But I've driven it 1400 miles from ATL to Boca Raton, FL and back several times and it's been reliable as hell. You're always going to have things that go wrong along the way though such as vacuum leaks, bad OEM Fuel pressure regulators, etc.

Most people will say ITB's are not worth the money for the power gains you end up with and maybe they're right, but that's not what it's about IMO. It's your car, do what you want with it. If you're more concerned about power numbers than pure epicness, then maybe ITB's aren't for you (or you need to build the tits outta your engine). Yes, the sound of them is pretty sweet (even better when tuned properly), and the throttle response is impressive as well.

If you're on clubroadster.net check out the AE101 ITB thread they have on there. TONS of info. That's the setup I'm running.

BlitzWing
03-06-2014, 11:45 AM
I didn't build an ITB set up, but instead went with dual Weber carbs. So I can help you with the throttle cable.

Typically you can adjust how far the end of the cable is attached at the throttle side. However, sometimes the amount of throw the cable needs before it maxes out will be different. To compensate for a shorter throw, there is an adjustment on how far the gas pedal travels. The adjustment is located on the upper end of the pedal. You want the pedal to hit the stopper at the same time the throttle body is in the full open position. If it isn't, you can damage components on the ITBs or the throttle cable itself.

It helps to have a helper inspect the throttle side of the cable while you adjust the pedal side. It is not that big of a deal.

The hardest part of the whole deal in some cases (at least for me) is to be sure all throttles are opening and closing at the same angle as the rest of the throttle bodies. Some systems are better than others as far as how much work it takes to get it adjusted and working properly.

thanks for the info I didn't know about the pedal adjuster.


I've had ITB's in my NA for awhile now. I might add that it's my DD. Certainly hasn't been perfected tuning wise with the ITB's.......I wasted my money on a shitty tune. But I've driven it 1400 miles from ATL to Boca Raton, FL and back several times and it's been reliable as hell. You're always going to have things that go wrong along the way though such as vacuum leaks, bad OEM Fuel pressure regulators, etc.

Most people will say ITB's are not worth the money for the power gains you end up with and maybe they're right, but that's not what it's about IMO. It's your car, do what you want with it. If you're more concerned about power numbers than pure epicness, then maybe ITB's aren't for you (or you need to build the tits outta your engine). Yes, the sound of them is pretty sweet (even better when tuned properly), and the throttle response is impressive as well.

If you're on clubroadster.net check out the AE101 ITB thread they have on there. TONS of info. That's the setup I'm running.

totally agree I'm not chasing a power number and with a MX5 I think the best and cheapest way to make more power is just to buy a different car. I want to make something fun and unique.

Jenvey got back in touch they are willing to tap the vacuum lines for me... they want £40 on top of the £720 for the ITB's I think for the sake of buying a dye and getting a new metal drill bit I'll try it myself.