BLiNK Motorsport AFM + timing mod - anyone tried it?

[paggers]

I read quite a long thread over the weekend on Nutz posted by by BLiNK Motorsport (thread here). These guys are in Cheshire so not too far away and apparently they prepare and maintain cars for one of the MX5 racing series.

According to the information they posted they do a couple of modifications to the NA 1.6 engine which will give a decent boost in power. For £80 they will tweak the air flow meter and adjust the timing which is calculated to give an increase of about 8bhp and 7lb/ft. For a further £100 they will give you a modified air flow meter which, along with the timing adjustment, can increase power at the top end by another 4-5 bhp with a small increase in torque across the range.

Someone did some analysis and the peak power increase between 3k and 6k rpm was 15% which is pretty impressive given that the replacement AFM plus tune-up comes to less than £200. So I was wondering if anyone has had this done as I'm seriously thinking of having it done to my car when funds allow?

[Mazda Mender]

I had a owner with a MK 1 that had a FMII that used them and spoke really highly of them, i'll get in touch with him to pop on.
M-m

[PaulH]

Tis quite a simple mod, did it on my Mk1, will dig out info but basically remove top of AFM, move gear against spring 4 clicks (either clock or anti-clock ?, that's why I have to dig up the info !) replace AFM top & hey ho a bit more flexibity throughout the usable rev range, with tweaking it allowed me to run my Mk1 in hillclimbing on the limiter which it wouldn't reach before although fuel consumption will suffer, seem to remember quite lengthy write up on the MA5DA Racing Forum & a how to do it, PH.

[PaulH]

Borrowed with acknowledgement to "Jon of Wiltshire " on the OC forum, as follows:
quote:
Method - Dead simple really. Carefully remove the silicon around the black D shaped cover on the top, and remove the cover. Clean off the old silicon and be prepared with a tube of new stuff - automotive, rather than bathroom. Make sure you get any bits out from inside. Now you'll see the rheostat that gives a resistance reading back to the ECU depending on the air flow, and underneath there will be a clock spring mounted in a toothed wheel. To one side is the ratchet that is used at the factory to calibrate the AFM - it's easy to see how this works. Mark the wheel first so you can go back if necessary.

By moving the toothed wheel clockwise, you tighten the spring, making the AFM read lower, and vice versa. By tightening the spring, you're essentially leaning the mixture, because the ECU 'sees' less air coming in (for the same actual airflow) and so orders up less fuel from the injectors. Less fuel in the same amount of air = leaner mixture.

If you have a gas analyser, or colortune, or some other way of reading the mixture directly, then you're in luck - just watch and adjust until it looks good. If not, you can adjust a click or two at a time and go for a drive and see how it goes, rinse and repeat. I ended up moving mine about 8 clicks clockwise, but this will be different for every car. You need to adjust the base idle each time you adjust the AFM - check out FAQ's for how to do this if you don't know.

I found that when it's about right, the metal brush that contacts the black track sits at the narrow end of the 2nd wedge-shaped segment at idle on a warm engine. It sat just inside the 3rd segment when I started, so that's very rich - and if it is in the 1st segment at idle it won't run right at all. When I've found the perfect spot, I'll post a picture. If anybody has a factory-fresh AFM who doesn't mind opening it up, perhaps you can confirm my suspicion that this is the right spot to aim for at idle? For best results you should use an analyser of some kind, though.

When you're finished adjusting, be sure to properly reseal the top, as it's essential that the rheostat doesn't become contaminated.

Result - Before, I had a significant step in power at 4k revs, it turns out this was because the <4k performance was so down, due to the richness. That's now completely gone. The top-end performance remains much the same - the ECU is open loop at this stage, so I don't think the AFM reading is used (correct me if I'm wrong). I'm still doing mpg calculations so will be sure that I've fixed the economy problem in a few days, but I've just had an MoT and fast idle results are: lambda=0.998, HC=018 and CO=0.029 (at natural idle CO=0.005), which are pretty good numbers so I reckon she's close now. She smells great, the lumpiness and hesitancy is gone, and bottom-end grunt is massively better. (Dangerously better it seems, as I nearly exited a roundabout backwards the first drive out! )

As always, fiddle at your own risk, but I hope this helps if you are suffering over-richness and everything else tests out ok.
unquote.

[paggers]

Cheers Paul, although the BLiNK mod goes rather further than the clock spring mod you describe and (according to their figures) gives a further 4-5 BHP. You can get the clock spring and timing done by them for £100 while they charge a further £80 for their customer AFM mod.

For me the main drawback is that for the AFM mod they need you to send in your AFM for two weeks, which is two weeks with the car off the road. Still, to get an extra 15 BHP I'm pretty tempted.

[PaulH]

Hi the spring reposition is a DIY job, search Miata sites in the US & Google MX5 Mk1 AFM mods, you will come up with a pictorial how to do it , it's easy !, Blink go steps further in that they change the internal electronics varying resistance values similiar to chipping, still need the car rolling roaded to get the best out of the mods though. I did the spring mod to my Mk1 1600 with 14 deg of advance, 50 thou machined head, vernier pulleys, a 4-2-1 branch, modified throttle body & free flow air filter (Pipercross) & got 131 BHP at 7,600 rpm, that was worthwhile although it had a lumpy bottom end, it all started with the AFM mod & one thing led to another !, rgds, Paul H.

[binarypunk]

For me the main drawback is that for the AFM mod they need you to send in your AFM for two weeks, which is two weeks with the car off the road. Still, to get an extra 15 BHP I'm pretty tempted.

I have an AFM that I cleaned up and put on the shelf as a spare. If you want to use it while yours is in for modding, you're welcome to borrow it.

[paggers]

Thanks Jon, that's a great offer. Just need to work out how to get it off you without too much hassle.

[binarypunk]

If you don't mind paying for the stamp, I'll post it off to you...PM me your address.

[BLiNK Motorsport]

Just to reply to the above,

we do hold some AFM's in stock now so can do the full package while you wait - we also have our own DynaPack Hub Dyno so everything will be Optimized and Checked for you before you leave.

We Hope this helps clear some things up

BLiNK Motorsport.

[Mazda Mender]

Just to reply to the above,

we do hold some AFM's in stock now so can do the full package while you wait - we also have our own DynaPack Hub Dyno so everything will be Optimized and Checked for you before you leave.

We Hope this helps clear some things up

BLiNK Motorsport.

We understand your plug , and don't mind the plug if you can spread more light on the subject....but it does not answer the question about your product? what if any is the power gain? etc which years and engine size do you cover? is it a simple plug and play? and cost etc......
M-m

[BLiNK Motorsport]

We understand your plug , and don't mind the plug if you can spread more light on the subject....but it does not answer the question about your product? what if any is the power gain? etc which years and engine size do you cover? is it a simple plug and play? and cost etc......
M-m

There is some more detailed information about the Modification here:

http://www.mx5nutz.com/forum/index.php? ... 112653&hl=

http://www.mx5nutz.com

The Modification is for the Mk1 1.6 MX5 - yes it is 'Plug & Play' and we do have deals on them for people having the car dyno tuned by us.

HTH