Dual Throttle Body Conversion - How & Why | Supercharged MX5 Episode 29

[@FastRust]

📈 Want to donate to getting my supercharged MX5 on the dyno - www.ko-fi.com/fastrust 📈 Thanks for your continued support 🤟🏼

[@RacecarsAndRicefish]

sorry to spam your comments but my build is finally done! your series here was a huge inspiration even though I used almost none of the same parts. Thanks for walking us through the entire process and making it feel achievable

[@jamespaterson1610]

I have the same car/set up as you and came out at 186 bhp at the crank with the 17% pulley and 5psi of boost. Straight from a Dr Hickson tune. 😊

[@FastRust]

1.8? Seems a bit down from what I've seen other similar setups make. Average seems to be around 180-190whp.

[@jimeggleton6474]

I am converting my mx5 with a M45 charger and I found your videos very informative. My car reg. is YF51 JKO !

[@sparkitzippy4383]

Just attempted and succeeded on my 2000 SC Miata Finally a factory idle !working that closed loop idle ! Megasquirt pnp

[@strikesss]

Also subbed! I just picked up an M45 and going to do this on my 1.6!

[@FastRust]

Thanks 👍🏻 Good luck with the build. Plenty of guidance on here!

[@SwayyCOMPETITIVE]

I was going to turbo charge my 1.8vvt Phoenix, but seeing these videos I've opted for the supercharging route. What an incredibly informative series, thank you James :)

[@FastRust]

Thanks! Glad it helped. Good luck with your build 👍🏻

[@jamesford8271]

Just bought a supercharged mx-5 and couldnt agree more with your point of view. Will certainly be looking to do this

[@goorgert1364]

Thanks for your video, Mate. It was helpful and enlightening. I am busy getting an Eaton M65 from a Mercedes to fit onto my E30 with the M50 engine. Everybody else takes the easy route to high power by turbocharging, but that is not what I want to do. I want a more linear form of boost, and not more than 15 Psi ever. It bothered me that the boost might come in too quickly, but now I can see the way forward. I am contemplating buying a Kenne Bell supercharger, but I live in South Africa and any form of technology has become super expensive due to the exchange rate.

[@-Just_Justin-]

I did a dtb setup on my miata, I went a little different route for execution though. I can agree 100% about the cruise and part throttle/throttle tip in. It is a small area to drive in especially hitting hills. I feel like the dtb setup allows for many more benefits.

[@FastRust]

Oh 100% hills were a nightmare with a single throttle body. You have zero modulation it's either full boost or decel. It's still not perfect with 2 but it is WAAAY better. Glad you have a similar experience 👍🏻

[@drivelinedynamics1723]

Cheers mate! I’ve always been a mini cooper person, but after showing my gf this video series, she’s taken advantage of my extra mp45. It’s a very different little roadster now, and she can’t get enough of the whine. However, she thought the BOV idea was great, she just tasked me with finding one that sutututu’s, which will be a task

[@FastRust]

Great news! Yeah it completely wakes the car up. I have a Chinese HKS which is supposed to make all those noises (not that I was after that - it was because it was free) but I don't get it. I think with the superchargers relatively low boost, plus you have a bypass valve she'll never get the stutututu noise. Sorry.

[@alecpedalerbriggs9876]

I don’t drink coffee so was happy to donate 2 to you. Your series inspired me and I’ll be starting my build this weekend. Look forward to seeing the dyno results, Thanks!

[@FastRust]

Thanks for the donation Alec and great to hear. Good luck.

[@RacecarsAndRicefish]

I'm finally finishing up my build and getting ready for my first start with my supercharger. I've got everything put together but I'm realizing I could've moved my throttle body to be in front of the supercharger. If you were to run just 1 TB, which spot would you put it? Is it worth the effort for me to relocate mine? anyways thanks for this series-- it really inspired me while these build videos were coming out Update: Running just 1 TB on my NA6 located by the supercharger produces a totally fine amount of noise, but unfortunately there's a side effect: when I close the throttle, any boost in the piping still makes it into my intake. And I can't run a BOV because there's nowhere to connect that vacuum line. Also it looks like NA6 throttle bodies (always?) have a second slot for an extra cable. So I'll be upgrading to 2 TBs shortly

[@Rich-n-Cooper]

Great update and the noise was one of the reasons i went turbo! Ive had a few Mini's running the charger setup and i love the simplicity and wine at WOT. Great to see the huge difference in idle noise for such a simple addition though. I've also used Alex and found him to be an incredible source of knowledge on the ME ecu.

[@FastRust]

It really has been the single best modification I've made to this setup. The car did my head in with a single throttle body. I'd like to do a Turbo build to compare the two.. but I think one mx5 is enough 🤣

[@PROZA4EG]

thx for the vid. helped me a lot. just acquired mx5 with mp45 and 2 throttles with really hard to press pedal. learned whats wrong

[@gilki274]

Just saw your vids for the first time a few weeks ago watched the whole mx5 series very good and helpful! planning on supercharging my NA on a budget in the near future, hope your able to reach your goal so we can find out how much power it makes all the best mate :)

[@FastRust]

Thankyou yeah, NAs slightly different with pipe routing etc but a lot of the series is still relevant. Me too. Not looking likely at mo though 😕

[@Toptechitsimracing9601]

love the dual throttle body setup , i would love to do a supercharged mx5 build but very expensive where I am from , may need to settle with a ITB Build

[@simon8197]

For God sake James, now you're making me think I should put a 2nd throttle on 😫 my cars a weekend /show car so loved the whine but took it for a couple hours run to my folks house and the whine did get on my nerves. Plus you're spot on with the acceleration issue, constantly on and off the throttle trying to maintain a certain speed

[@FastRust]

I know the feeling! It's worthwhile if and when you get round to it. Glad you knew what I meant about the crusing issue. Annoying isn't it. Which kit do you have?

[@simon8197]

@@FastRust I got one of the Ed Kellet "flat pack" kits of good ol' Simon Sears 😁 so should be able to get one on there without any modifications or changes. Like the idea with protecting the silicone tube to the air filter. Mines already showing signs of wear from rubbing on the abs module and don't even use it that much

[@FastRust]

Ah dead easy with the G42 kit, get another throttle body on there you won't regret it!

[@matiasweisskapp6656]

Hi James, thanks a lot for the whole series. I have a similar MX5 VVT and did all the mods you did. I have a different setup for the supercharger and built the brackets myself for a M62. For the tune I also hired Alex based on your advise, but to put the SC to work I would try to tune it myself. Would you mind sharing your tune for me to use it as a base to start? Many thanks!!

[@dennisngugi6674]

Contributing to your build i think also using an open air cold air intake contributes to the whining of the supercharger, i think using a factory air box would reduce the whining significantly. This thought is derived from how cars whine when you remove the factory air box and replace with an open air cold intake.

[@jamespaterson1610]

James!! My local dyno place offer power runs for £45! There must be something like that near you 🙏

[@FastRust]

Hey mate. Just for the record this will be a full tune, not just a few pulls. Even by a remote tuners admission they'll be able to get more power on an actual dyno. I had toyed with the idea of doing a before and after to see what the actual increase would be.. but decided against it.

[@basmourik234]

I was confused about how to connect a 2nd cable😂 barely any info of "how" thanks for the video

[@FastRust]

It's pretty straightforward tbh. Use the existing bracket on the side of the inlet with a couple of washers and M6 nuts for one barrel adjuster. Then you'll need to make some kind of bracket at the other end for the other adjuster. One end of the cable will already have a nipple soldered on. You can solder one on the other end or do what I did and buy some with a grub screw to clamp onto the cable. From there you can use either barrel adjuster to set the throttle pre charger to lead the post throttle by a few mm

[@5Dimsims]

Hey mate great video, clear info 👍. I was wondering what tuning software you used

[@FastRust]

Car has an ME221 ECU so you have to use MEITE

[@brysonhammons1712]

Did you have any other issues other than the sound with only one throttle body?

[@FastRust]

Yep. Driveability at cruise was crap. Explain it in the video.

[@edoardomanzotti3733]

Any chance to have a before/after video? I got a similar setup and i'm curious about the improvement, also the cable guide for the stock tb is the one from shapeways?

[@dimitarsivkov2785]

Where I can find this shapeways throttle adapter you are using. I have searched the web without any results..😢

[@ohnoitisnt]

I'd never fit a blower to a car without a pre throttle... Im all up for blower noise but its so loud its painful. Can you now get rid of the recirc valve?

[@strikesss]

Looks like G19 just made a dual throttle body set up!

[@FastRust]

They are I've sent them some measurements to help work out clearances etc. I think they're pretty close to putting it out.

[@chr1Stos]

The second throttle cable form what car is it?

[@FastRust]

Ebay

[@chr1Stos]

@@FastRust ok.. How can I search it?

[@garagecedric]

It think the noise is more of a "feature" of the specific setup, not specifically the m45 mini supercharger(im new in here, i dont know all the details of your car yet ). Ive been in a few Porsche 924s with the supercharger kit based on the mini charger, and there werent much supercharger noise at all at low loads motorway driving, it comes on at wot.

[@manuqtix8874]

The easiest mod you could’ve done was to place the throttle body before the supercharger. That’s how the mustang supercharger is like

[@FastRust]

Not as simple with these setups, unfortunately! You could get away with this setup if you didn't have an intercooler.. like the old Jackson Racing kits which had a 'dummy' throttle body you put in place of the OEM part.

[@toweliethetowel-nc6mq]

Did you keep the blow off valve in this setup? How is it going now? And what length throttle cable did you buy? I’m starting my build in the next few days

[@FastRust]

Yes all still exactly as it was in this video, whacked a load of miles on it, runs great! Can't remember length of cable just measure it. You can always cut them shorter.

[@RacecarsAndRicefish]

Hey I'm desperate to know what throttle cable you got to run between the two. I'd like to avoid buying a bunch that don't fit like I did for my supercharger belt

[@drewwagar]

I wonder if this is more down to the supercharger itself? Mine is a mk1 mx5 with a single throttle body and an MP62 and I have had none of those issues at all. There is no supercharger whine off boost, whilst audible but not excessive on boost, so I never saw the need for the second throttle body at all. I also don't have the moderation problem you mention - mine just feels like a big NA engine. It has 190bhp at the rear wheels on a dyno tune. you can see it in action here > kzbin.info/www/bejne/ipLNdKF9j9GGnZY

[@FastRust]

I've watched that video before. Nice car! All I can think (in terms of noise) is that to get the M45 to perform on a 1.8 you really need to be overspinning.. that in turn cranks up the whine. Whether this also affects driveability is another question entirely.. Assume you are running the stock pulley on the M62?

[@drewwagar]

@@FastRust Yep, the stock pulley. :) It's effectively at the minimum state of tune it can be. I could add more bhp by a smaller supercharger pulley or a crank overlay, but I find it's more than enough (and super reliable) as it is.

[@blackzoomba7440]

Which throttle cable did you use to link the primary throttle body to the secondary? There are a ton of options on eBay, but I don’t see any that look like the one you’re using.

[@FastRust]

The exact listing has changed but it was a Venhill Universal Throttle Cable. Approx 1 metre long, think I ended up cutting it down a bit.

[@keithkennedy411]

Hi James with the benefit of hindsight would you have preferred to go turbo charged or even tweaked standard

[@FastRust]

Good question.. I'll always love a well tuned NA engine. Fact. But decided to change it up and go FI with this build. S/C vs Turbo?? Having not been in a turbo MX5 it's hard to say. I do think turbo is a more expensive route to do right, which is why I went S/C. Besides I'm saving my turbo build for a V8..

[@BestSuppressed]

What's the diameter of the silicone tube going from the bypass valve? I can't find the diameter anywhere online!

[@FastRust]

Good question. 30 something.. I've just backtracked through my orders but I can't see it. Have you not got a bypass valve you can measure?

[@BestSuppressed]

@@FastRust Yea I do, but it's in the car which I don't keep at home atm lol. I think it's 38mm after ordering 45mm ducting 🤦‍♂, will have to adapt it a bit probably!

[@FastRust]

From memory it's either 36 or 38.. definitely wasn't in the 40s!

[@shannonvandijk958]

Hey. Love the car! Do you know what causes the supercharger to be so loud without the added throttle body?

[@jamespaterson1610]

In my case, my sc mounted bypass valve was venting out into the atmosphere. So on idle/cruise the valve is wide open and blasting air and noise to every corner of the neighbourhood.

[@FastRust]

Yeah it's mostly down to the fact the supercharger is unthrotted. It gulps all the air it wants, compresses it into a shut throttle body and blasts it out of the bypass like James says. Every car that has a supercharger from factory runs a throttle before the charger. Much better setup.

[@st.dardust_garage]

@@FastRust not m111s... that's why I was wandering on what to do in case I would remove the stock airbox, because the thing just has a bypass valve. I love the whine while accelerating, I think it's kind of annoying while releasing the throttle, and every video I see of my engine with modified intake it just sounds good while accelerating and obnoxious while closing the throttle. I always wanted some kind of hellcat sound ( intermittent whines, which is just lovely), but i tought it was impossible to do so without actually changing the throttle body position all the way back to the SC. Never tought of fitting 2 throttle bodies. Could I remove the bypass valve doing so, or that would still be needed? Thank you for the video, it's giving me good ideas

[@toweliethetowel-nc6mq]

Just a thought, could the inlet from salon motorsport be used along with g19s second throttle body adapter plate? I would imagine the second throttle body does not have to be right by the supercharger, maybe it could be positioned any where along the intake pipe between the air filter and the supercharger inlet. Great series, I’ll absolutely donate to help your build

[@toweliethetowel-nc6mq]

Just suggesting this as the tr lane inlet is no longer available

[@FastRust]

I'd imagine any inlet could be adapted to work with the rest of the G19 kit. I have recently been contacted by G19 and it seems they are planning to revise their kit to use a 2nd throttle body. Might be worth keeping in mind if you haven't already ordered one.

[@FastRust]

& many thanks for the donation!

[@toweliethetowel-nc6mq]

The bofi supercharger kit uses a bypass valve from the mini. Do you know what the purpose of that is? Would it do the same job as dual throttle?

[@FastRust]

@@toweliethetowel-nc6mq no bypass is totally different to the throttle, it opens when the intake is in vacuum and lets air around the rotors of the supercharger

[@JunglistMogwaii]

It costs £30 maximum for a dyno run (normally 3)....

[@manuqtix8874]

Long time no see hey! Hi how are you, where have you been all this time? I was wondering what happened to your miata

[@FastRust]

What's up! House has taken priority recently.. real life stuff. Miata still here 👍🏻

[@simonwhatley4533]

Wish I’d seen this earlier 😂

[@FastRust]

You and me both!

[@gavinferguson]

just found this channel but why the babe station music

[@FastRust]

Cos it's free

[@bal_723]

so 2 throttle bodies are good because supercharger wont choke anymore, understood

[@FastRust]

No, pretty much the opposite

[@mhh3]

is this channel dead?