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Quantum ST170 update-
Nickp - 16/12/18 at 06:46 AM

Been having a few issues with the VVT controller as it kept losing the signal from the cam sensor so was working intermittently and affecting performance. So I rerouted its cable further away from the coilpack and also earthed the shielding, which seems to have cured the issue.
So I took it for a test drive this morning and it goes like stink now!! My little local speed test shows that it's at least as quick as my previous Z4 3.0, RX8 231 and even the MR2 3.0 V6. Pretty impressive to say it isn't even set up properly yet.
However, it has a very weak self centering action on the gear change which was present before the engine swap. All gears select fine but you just need to be very careful and deliberate to get the right one. Is this likely to be weak/broken springs in the gearbox itself or are there some in the gearchange?

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FamilyGuy - 16/12/18 at 11:53 AM

If it's a standard st170 setup there are no centering springs outside of the box itself. I've modified my st170 gear change so it's nothing like standard now but I believe the st170 guys recommend removing the counterweight on the gearbox lever to improve the gear change. Not sure if that would help.


Nickp - 16/12/18 at 02:20 PM

quote:
Originally posted by FamilyGuy
If it's a standard st170 setup there are no centering springs outside of the box itself. I've modified my st170 gear change so it's nothing like standard now but I believe the st170 guys recommend removing the counterweight on the gearbox lever to improve the gear change. Not sure if that would help.


No, I've mated the ST170 engine to the original 5spd BC gearbox from the Fiesta.


wonderfulweasel - 16/12/18 at 06:12 PM

I had similar when I fitted a 5 speed to my mk2 Fiesta back in the day. I think it's the same 'box.

Iirc there's a small sprung plastic saddle at the base of the gear lever, which centres the stick, which had worn. I changed this for a new one and nice and positive centring again.


Nickp - 16/12/18 at 08:58 PM

Thanks, I'll take a look at the gear change mechanism. I'm hoping to make it a short shift too so hopefully it'll be sorted at the same time.

quote:
Originally posted by wonderfulweasel
I had similar when I fitted a 5 speed to my mk2 Fiesta back in the day. I think it's the same 'box.

Iirc there's a small sprung plastic saddle at the base of the gear lever, which centres the stick, which had worn. I changed this for a new one and nice and positive centring again.


Nickp - 9/2/19 at 12:02 PM

Just had the car for a power run and to check for safe fueling at Autotronix Developments near Sheffield.
No adjustments made and straight out of the box it's making 178.6bhp @ 6548rpm and 164lb/ft @4609
Happy with that from a £100 ST170 engine on ZX6R bike carbs
Fueling was safe but a tad lean at the top end so gonna go with new 2.15mm mains (currently at 2.1mm drilled).
Should make 180+bhp with a few tweaks. Plenty for an 800kg fwd car with no LSD