BBR MX5 225 NC, or any ITB’d car question

BBR MX5 225 NC, or any ITB’d car question

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Discussion

philrs03

Original Poster:

101 posts

97 months

Tuesday 13th February
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Afternoon all, I’ve recently had my MX 5 NC back from BBR where it’s had a Super 225 kit fitted. The car is awesome at max chat, or driving “enthusiastically” but seems to stall consistently (hot and cold- although I expected it to happen when cold) when the revs drop. I.e, if you’re pulling into a parking space, or crawling along in traffic and need to dip the clutch. It also seems to me it’s over fuelling, the exhausts are covered in soot and it seems to be horrendous on fuel. I couldn’t care less about fuel economy, I’m just using it as a potential diagnosis point!

Has anyone here either got a 225 MX5 or any other car moderately tuned running ITB’s? I’ve been told by BBR that it’s totally normal for them to cut out at low revs even when hot, but this being my first foray into an ITB’d car I wouldn’t mind a bit of a steer.

Cheers all..

Krikkit

26,538 posts

182 months

Tuesday 13th February
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Cutting out when hot or cold like this is a sure-fire sign that it needs better mapping. Is it on the standard ECU?

You should be able to have it sorted by someone familiar with ITB cars - two that spring to mind are Wayne at Chipwizards up north, and Sandy Brown in Devon.

E-bmw

9,238 posts

153 months

Tuesday 13th February
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As above 100% it should be tuneable enough to remove the issue, as to whether the OE ECU can be tuned or a piggy-back ECU required I don't know on these.

philrs03

Original Poster:

101 posts

97 months

Tuesday 13th February
quotequote all
Krikkit said:
Cutting out when hot or cold like this is a sure-fire sign that it needs better mapping. Is it on the standard ECU?

You should be able to have it sorted by someone familiar with ITB cars - two that spring to mind are Wayne at Chipwizards up north, and Sandy Brown in Devon.
Thank you mate. I did suspect that, but BBR had a pretty nonchalant attitude towards me/that issue when I questioned it. It’s still running the standard ECU with a starchip BBR map on it. I’ll have to try and take the hit and get it back up to them, shame as it’s a 200 odd mile round trip, I spent just shy of £8,000 with them. I would have thought that would have paid for some better after sales care!

Tommo87

4,220 posts

114 months

Tuesday 13th February
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The marketing material suggests that they reuse the existing ECU which would suggest that it should work out of the box, on any given standard car.

Unless they have forgotten to plug something in, or to adjust a throttle stop, then something in your idling circuit is faulty and they never picked it up.


I have heard similar stories in the past for one size fits all postal remaps, where the ‘software installer’ (I’m not calling them a mapper as they don’t create a custom map) doesn’t check that every sensor is working to bau tolerances, before installation.


One thing you could try is for a local Mazda specialist to stick on OBD reader on and look at live data for all those sensors to see, if anything is out of whack.

Edited by Tommo87 on Tuesday 13th February 15:47

philrs03

Original Poster:

101 posts

97 months

Tuesday 13th February
quotequote all
Tommo87 said:
The marketing material suggests that they reuse the existing ECU which would suggest that it should work out of the box, on any given standard car.

Unless they have forgotten to plug something in, or to adjust a throttle stop, then something in your idling circuit is faulty and they never picked it up.


I have heard similar stories in the past for one size fits all postal remaps, where the ‘software installer’ (I’m not calling them a mapper as they don’t create a custom map) doesn’t check that every sensor is working to bau tolerances, before installation.


One thing you could try is for a local Mazda specialist to stick on OBD reader on and look at live data for all those sensors to see, if anything is out of whack.

Edited by Tommo87 on Tuesday 13th February 15:47
Thanks Tommo. I suspect something is amiss but it doesn’t throw an engine warning light at me at all, which I think it would if there was a sensor issue? Could it be the ITB’s being out of adjustment themselves do you think?

wilksy61

380 posts

117 months

Tuesday 13th February
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I had a NC on ITB's from BBR and it did stall as well either cold or hot, but it was manageable in the sense that you knew it may stall and therefore needed to be throttle managed.

I found that it would stall the most if you came to a roundabout at speed and then had to slow down quickly using the brakes as opposed to going down the gears.

I never raised the issue with BBR as I didn't feel it was too much of an issue, however if I had lived closer or it was my every day car then I may have asked for it to be looked at.

philrs03

Original Poster:

101 posts

97 months

Tuesday 13th February
quotequote all
wilksy61 said:
I had a NC on ITB's from BBR and it did stall as well either cold or hot, but it was manageable in the sense that you knew it may stall and therefore needed to be throttle managed.

I found that it would stall the most if you came to a roundabout at speed and then had to slow down quickly using the brakes as opposed to going down the gears.

I never raised the issue with BBR as I didn't feel it was too much of an issue, however if I had lived closer or it was my every day car then I may have asked for it to be looked at.
Thanks Wilksy. Mines not a daily either really, more of a nice weather/track toy, but it’s definitely less manageable than yours by the sounds of it. I wouldn’t be bothered if I could keep it ticking over more easily but currently the only way I can stop it stalling (when in traffic, or very slowly approaching a stop) is to use the handbrake and keep the throttle at a gentle constant. Clearly happy to live with some compromise but even with my liberal attitude to what’s acceptable for a modified car, this isn’t really workable. Did you have the same experience with the fuel smell?

Sensibleboy

1,144 posts

126 months

Tuesday 13th February
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Do the ITBs use drive by wire or a throttle cable?

wilksy61

380 posts

117 months

Wednesday 14th February
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I had no fuel smell with mine, at least I don't think I did as I never drove it with the hood up, I only deployed the hood when in the garage and there was no smell of fuel when parked up for days or even weeks at a time.

Belle427

8,984 posts

234 months

Wednesday 14th February
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What do BBR say about it?
I heard they are dreadful to deal with which surprises me as their packages seem good.

Pent

268 posts

20 months

Wednesday 14th February
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as above.. never heard a good word about BBRs customer service, take your money and run is the phrase.

£8000 is a st ton of money for a car that stalls all the time.. think i rather drive my standard one , actually im building a turbo mx5 for less than that.

IF you want proper decent advice , give Performance Link a ring , alex is amazing

DVandrews

1,317 posts

284 months

Wednesday 14th February
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I’ve converted a few hundred engines from plenums to ITBs and none of those suffer from stalling, when they run on a plenum the IACV usually opens a little to soft land the engine when the throttle is closed, the extra air modulated prevents the engine from stalling. With ITBs the IACV is rarely retained so the mapping has to be very carefully done, especially if the ECU cuts fuel on overrun as the engine will very rapidly dip and the ECU may miss the opportunity to rescue it from oblivion. Some judicious adjustments to the idle personality and maybe changes to fuel cut on overrun may cure it, but it’s definitely a mapping issue.

Dave

E-bmw

9,238 posts

153 months

Wednesday 14th February
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^^^^ Listen to this above all of the rest of us telling you the same.

stevieturbo

17,269 posts

248 months

Wednesday 14th February
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philrs03 said:
I’ve been told by BBR that it’s totally normal for them to cut out at low revs even when hot, but this being my first foray into an ITB’d car I wouldn’t mind a bit of a steer.

Cheers all..
Absolute nonsense it stalling is normal

If it was a highly tuned screamer, big cams, difficult clutch etc etc, then I'd say idle etc could be a lot more difficult for sure with more opportunity for stalling, but this does not sound like one of those cases.

How do they control idle with this conversion ?

Although I will also add....perhaps large changes can also require some driver adaptation and learning too. So just depends if that is a factor too.
But for just a swap from an OE intake, to ITB's, if anything when done well, should nearly offer better driveability


Edited by stevieturbo on Wednesday 14th February 20:50

philrs03

Original Poster:

101 posts

97 months

Thursday 15th February
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Thanks for all the replies, I am really disappointed with the customer service. I’d have expected them to offer to trailer the car back to their place at least to sort it out. I wouldn’t be overly bothered if it was manageable but it isn’t really. It’s a shame I’ve only found out about the negatives after the fact. The car itself (at full whack) is absolutely brilliant fun. It sounds epic and goes like a rocket, but this experience has taken the edge off a bit for me. Neil the owner, to me anyway, has been great. He seems a nice guy, but some of the people that work there (I won’t name names) left me apocalyptically angry when trying to get this issue resolved.

They are more than happy to take the car back and play around with it, but as I pointed out to them, why wouldn’t they be? It’s a 300 mile round trip, a full day, two tanks of fuel (mapping and dyno runs) and all to sort out an issue they themselves have created. Essentially a them problem is now a massive me problem.

It is what it is, once it’s sorted (which I’m sure it will be) it’s a mark and avoid for me going forward. Which is a shame, because it’s the first and last time I’ve ever paid someone else to do something to one of my cars. Lesson learned!!

Belle427

8,984 posts

234 months

Friday 16th February
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Maybe try using social media to your advantage.
I don't mean slagging them off but maybe asking a few strategic questions on certain groups if they exist.

philrs03

Original Poster:

101 posts

97 months

Friday 16th February
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I haven’t got social media, other than PH I don’t really do much digital interacting! It’s interesting that the general word on the street is their customer service attitude is take the money and run. I’m trying not to dwell on it as it just irritates me. Hopefully I can get the car back up there soonish and they will square it away/redeem the poor after sales show so far! Thanks again for taking the time to reply!

DD3566

76 posts

75 months

Friday 16th February
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Sadly from my experience BBR's customer service (and sometimes the quality of their work) is shocking!

Paid £7500 for a Stage 1 Turbo kit on my NC, plus Wheels and Suspension. Told it would be 1 week to complete the work, and to collect the car and hand back the courtesy car on X date. Brilliant I thought. Went to collect the car on X date and there it was parked outside, ride height was abit high but hey maybe the springs haven't settled down to their final height? Sat in the waiting room, Neil came out on the phone and said "Be with you in a minute". Over an hour passed before he finally came out to speak to me, only to tell me they hadn't fitted the suspension due to one of the dampers having a leak (apparently). So they thought I might want the car with standard suspension and to drop it back on the following monday to have the dampers fitted. I wasn't too impressed at having to wait an hour for him to tell me the car wasn't fully complete, he could have rang or emailed ahead of time asking if I wanted to bother collecting the car. Seemed like a lack of common sense tbh

A week later I finally collected the car with the complete suspension fitted, and everything was great! For about a month, then I started getting smoke blowing through the vents and out of the bonnet. Back to BBR, turned out the oil feed to the turbo was leaking onto the manifold. Fixed under warranty and all was good....until 2 weeks later even more smoke. This time it was the oil drain leaking, so back to BBR to be fixed again.

After this the car was great, worked well for the best part of a year and was serviced by BBR themselves. That is until about 14 months after conversion (and crucially, 2 months after the warranty expired) and the turbo itself let go. During a spirited drive through the Cotswolds the turbo started making a horrible grinding noise above 3000 RPM. Back to BBR yet again and their diagnosis was the oil feed line got blocked due to "poor quality oil" overheating and gumming up the feed line. Which was amusing as they had done the last oil change and provided the "poor quality oil" 6000 miles ago (mostly daily driving duties, never tracked). When I had asked them about oil change intervals upon very first collection they recommended sticking to the Mazda OEM interval of 10,000 miles. They did agree to forego the labour charge to replace the turbo, but as it was out of warranty I had to pay £800 to replace the turbo core. After this I completely lost faith in the car, knowing that a brisk drive on B Roads could potentially kill the turbo yet again. Ended up selling the car a few months later and buying a Vauxhall Monaro instead.

After all this I would never recommend BBR to anyone, once they have your money they couldn't give less of a **** about you or the car. For £7500 (back in 2017) I would expect the system to be robust and not defeated by some Oxfordshire B Roads. Looking back now I was far too meek and should have demanded more from BBR in terms of rectification. The whole "poor quality oil" line still annoys me to this day, and i should have made them stand by their work and sort the dead turbo free of charge. Live and learn I guess

Quick edit, nearly forgot about the fact that the engine mapping caused the OEM 2nd Catalytic Converter to completely disintegrate. The exhaust used to pop and bang quite alot, which seemed to be slowly breaking up the cat bit by bit. Had an MOT fail due to emissions, after sticking a camera down the exhaust section I found there was literally no Cat material left at all. The only other option is that BBR decatted the exhaust without telling me (which I doubt, but at the same time it wouldn't surprise me). Again, pretty poor for a car which was advertised as passing an honest MOT!

Edited by DD3566 on Friday 16th February 09:34


Edited by DD3566 on Friday 16th February 09:56

Megaflow

9,438 posts

226 months

Friday 16th February
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DVandrews said:
I’ve converted a few hundred engines from plenums to ITBs and none of those suffer from stalling, when they run on a plenum the IACV usually opens a little to soft land the engine when the throttle is closed, the extra air modulated prevents the engine from stalling. With ITBs the IACV is rarely retained so the mapping has to be very carefully done, especially if the ECU cuts fuel on overrun as the engine will very rapidly dip and the ECU may miss the opportunity to rescue it from oblivion. Some judicious adjustments to the idle personality and maybe changes to fuel cut on overrun may cure it, but it’s definitely a mapping issue.

Dave
What he said ^

ITB's, and for that matter twin carbs, are a real bh to set up correctly for light load running just off low idle, because the smallest change in throttle angle results in a huge amount of additional air, purely because a function of the massive throttle area they now have. For example big power LS V8's run ~95mm throttles giving 7088mm^2 vs 4 x 40mm throttles on a ~2.0L 4 cylinder engine is 5026mm^2, feeding damn nearly 1/3rd of size the engine!

They can be set up correctly, but it takes a lot of time, doing the not very glamorous low speed, low load work, without the power runs.