Where is the Section for NA ITB Tuning

Welcome NickNock,
I would suggest you contact Bofi Racing and they will sort you with all the advice you need. If you were a MX5OC member you will get discount :wink: on the parts you purchase from them.

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This is what ITBs are for !!!

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Good read man I adore a good itb build, also a fan of the slow build as my project is taking an eternity

Got any photos of the setup?

Hi all, thanks for bumping this thread into view Benji93. This is very interesting.

DickieRltd, do you mind if I dm you and pick your brains please?

Cheers,
Guy

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I see g19 are developing a plenum kit to run itbs with their turbo kit, wonder if thatl come any time soon, Iā€™ve been considering getting another mx5 to itb to have along with mines which is 90% boosted Iā€™ve just taken a step back as it was to take all winter :joy:

Thereā€™s quite a few good looking kits available now and it seems reasonably priced for the noise and bants that it entails

Hi Folks,
Having waited for a couple of years BBR have just released the ITB kits for the earlier Mx5s.
They are now on the BBRGTI website.
I am sure that some of you have seen them at the OC Rally.
I have just bought a set to fit onto my car which is running a Mk2 Head on a VVT block.
The current Danst set up always was a tempory solution for me so I will be changing over to the BBR set in the next couple of weeks when they arrive at work.

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ā€œwhen they arrive at workā€
Hiding parts from the wife again? not that I would do thatā€¦ :innocent:

Ha Ha,
Its more the fact that there is someone at work from 7am to 6 pm.
Hiding things from the Wife is just a nice by product !!!

Hi Folks,
The BBR ITBs arrived and are now installed, They are a tighter fit than the Danst set up due to sitting lower in the engine bay and having a PX600 filter rather than PX500 on the Danst set. It took three hours of spannering to do the swap and then a few more hours setting up the ECU which had to be enriched and have cold start worked on.
Going from 42mm to 45mm meant that its lets quite a lot more air in at the same throttle opening. Its driveable but not ready to be Driven !!
Rolling road session to get it dialled in on Wednesday PM

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Very exciting.
Hope youā€™ll be able to let us see and hear these at some point :pray:

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I am currently in the final stages of building an engine with ITBā€™s for my 89 Eunos myself!

It is an Interference forged 1.6 long nose engine with a compression ratio of 11:1.

As for other bits and bobs Iā€™ve added to it, they are Audi R8 Coils, G19 Coil bracket, Bosch oil temp and pressure sensor, knock sensor, AWR engine mounts, and the most recent addition in the form of a Hummelink ITB kit.

It also has an I.L Motorsport 4-1 header on it too (still looking into the rest of the exhaust, any advice would be great).

Will be hopefully running an ME422 as well to keep it looking original on the interior.

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Welcome to the Madness.
You will have fun with it !!!
Have you uprated the oil pump gears or fitted an uprated harmonic damper as well as timing belt upgrade.
I have a Eunos 1840 with BBR ITBs running stock rods and pistons in a VVT Block but with an ATI Harmonic damper I have had it rolling road tuned at 8000 RPM.
The noise was painful.
I do not track the car so it only rarely sees over 7500 rpm.
I just wanted to see if I could hit 60 MPH in second gear. ( Still not tried it though )
I am running a complete 2 1/2" Manifold back exhaust system from M2 Motorsport

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Currently have a YSK Oil pump fitted and just a new OEM Harmonic damper.

List of mods done below:

  • 1993 B6 bored out +1mm to 79mm (1638cc), skimmed to 11.1:1 Compression
  • Supertech 10.6:1 79mm Forged Pistons
  • Maxed speeding rods (checked and sized)
  • Polished Crankshaft
  • YSK Oil Pump
  • GMB Water Pump
  • Piper 285H ā€˜Ultimate roadā€™ 266/256 8.89mm cams from blanks (not regrinds)
  • Full valve job (45 degree cuts) and exhaust guide k-liners
  • Rebuilt hydraulic lifters
  • Valve springs checked and matched

Engine rev limit is around 7500 so not high enough that iā€™ll really need to get an uprated harmonic damper (Plus it will be a pain to take everything off again, time it etc).

I shall look into that exhaust system. I will also be running a 6-speed gearbox and 4.1 Torsen too

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7500 RPM is high enough on stock hydraulic lifters.
Looks like a good spec for fun.
A 2 1/2 inch exhaust system might be too big for that spec.

I can always upgrade them in the future too.

Iā€™ve got 4-1 I.L Motorsports header fitted already which is a 2 inch which is probably a good size

Iā€™ve got something similar with a 1.8 bored out to 1.9 with 85mm 12:1 pistons, titanium valve springs, catcams hot street cams etc. I think itā€™s coming up to c.200bhp. a lot of work for not a huge amount of power, but sounds good at least.

Would recomend exhaust for sure, racing beat manifold made quite a noticeable difference on mine.

Hi,
I am in the process of collecting parts for an unusual engine build.
I am de stroking an 1840 Mk2.5 block to drop the capacity down to 1796cc using 85mm high compression Wossner pistons.
Its a bit of a project for motorsport use to fit into the local engine size structure.
It will be using the existing BBR ITB kit.
I have some more parts to buy before I can start assembling the engine.
The engine geometry will end up almost the same as some Red Italian performance cars and some un namable german ones.

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I took a differnt route and I hope you donā€™t mind it being a 2.5 Sport.
And the wife still needs to be told what has been going on in the garage.

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Mind ?
Do show us and tell us more !!!

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