Trav’s Race Build: from B6 to Big Bore BP-Z3

[GR124]

This is a great story. I suppose now that the CAMS are late you have to return to the dyno which costs money.
I know how you feel, I ordered a turbo from Ebay/sparesbox, Ebay said a week, Sparesbox said it would be another month, sparesbox have just told me add another two months to receive that part that Ebay said a week. AHHH
As I was typing sparesbox phoned me and has sorted it, No T flange housing, now a vee band, which will suit. 6 weeks later and I should see it.

Anyways, please don't let the shared journey end here lets us know how you go.

[Ross]

Regularity starts tomorrow according to the website.
Good luck Trav, it's been excellent follwing your adventure.

[Scoota]

Hey, thanks everybody!!! I’ve really enjoyed sharing this little adventure, so why not keep it going!

We are here at Bathurst, and in the pit marquees it’s MX-5’s as far as the eye can see!!!





And here it is, the most important sticker in Australia (to me)...



I passed scrutineering!!!! But not before this happened...





I failed scrutineering, and my heart stopped, and the world stopped turning, and my heart sank, and all of those metaphors for intense fear and loss. My brake lights didn’t work. Four months of my life, many thousands of dollars, and ALL of the family brownie points, and I failed scrutineering because my brake lights don’t work. Gaaaaaaarrrgghhh!!!!!!

But it’s okay! All I had to do was plug the appropriate plug into the appropriate brake switch socket and we had brake lights!!! Thank all of the gods. Even the silly ones.

So, I went back to the scrutiny tent, collected my log book and my magical green sticker, and the delightful scrutineers had no idea of the trauma that I had suffered (at my own hands, admittedly).

So here we are at Mt Panorama!!!!





Tomorrow, I get to actually see how this beastie goes, and we find out if I can remember how to drive it!


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[KevGoat]

Always the little things...

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[Scoota]

Hi Folks.

I survived Day 1 of the Challenge Bathurst Regularity Trial and I can confirm, Mount Panorama is thoroughly terrifying circuit. The concrete wall, the blind corners, the blind crests, the SPEED!!!! I’m feeling like an absolute rookie out there, for a bunch of reasons that I will now explain.

I have problems with the car. When the car is cold, it starts and runs on only 3 cylinders. It sounds like a 1970’s Beetle. After about 30 minutes of farting and wheezing, it clears it’s throat (after being turned off) and roars into life. This has got me stumped. Some are suggesting that my ignition harness is crook, some are saying coils, others are saying that it’s my lash caps (shims) in the head. On two occasions today, I sat in the car waiting to enter the circuit, with only 3 cylinders firing thinking to myself “Okay, when we get the signal, I’ll just drive out of the marshaling area back to my pit garage and try to figure out what the hell is wrong.” On both occasions, I stopped the engine a minute or so before the lass blew the whistle to indicate that we should proceed onto the circuit. When the whistle blew, I turned the key and the engine fired on all four cylinders. I roared out onto the track and did my racing driver thing.

Can someone please enlighten me as to what the devil may be going on??

I have another problem with the car. The throttle tip-in is still rubbish, so I can’t blip the throttle and rev-match on down-shifts. When I hit the throttle after having been off it, the engine bogs. This may sound like a small issue, but it’s not. It’s extremely unsettling when you’re trying to brake hard and manage weight transfer and adhesion on a racetrack. When I down-shift I have to slowly release the clutch and let the engine revs come up to match my road speed. I’ve never dríven like this, so it’s very foreign to me, and it’s really messing with my ability to commit to any kind of hard braking.

Also, Mount Panorama is a properly scary track. I haven’t dríven the car in anger for a good 18 months, so that’s not helping either. The car is also very different. I kind of feel like I’m doing something familiar, but it all feels new. Like I’m trying to write with my left hand (yep, I’m right-handed). I know what I need to do, but it’s not coming easily to me.

Anyways, tomorrow is another day. My strategy is to start the car well before my session, warm it up and hopefully get it running properly, then keep it warm! I’ll get into serious fault-finding mode after this meeting.

My best time today was a 3:05, which is nothing to write home about. Some of the lads here in similar cars are doing 2:53’s, so I’ve got a long way to go. Someone said to me today, “At Mt Panorama, you can’t rush it. You have to let the track speed come to you.” I’m a pretty patient sort of a fella, so I’m just going to take it easy and see if I find any speed tomorrow.

Wish me luck!!








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[Scoota]

Day 2 is done and dusted, and I’m happy to report that the car is on the trailer, wheels down and and unmolested. I’m lucky to have made it here, and I’m very grateful to be going home with the car intact.



It’s not all good news though. My second session ended prematurely when the car went into 3-cylinder mode coming out of The Chase (almost the bottom of the mountain). I limped along to the Mountain Straight Gate and then pulled off the circuit onto the paddock. That was the end of that session. After about the 15th off-and-on routine it fires on all four again, but it too late to rejoin.

When session 3 came around, I elected to leave the car in the pits. The prospect of having the car go into limp mode half way up the mountain seemed like too great a risk. I don’t think it would have made it out of The Cutting if it had happened somewhere beforehand, and I didn’t like the idea of getting poke-axed in a stationary car. So, I pulled the pin after having only done about 6 laps today. Not ideal, but I feel like I made the right decision.



The good news is, those 6 laps were spectacular. I was in a completely different headspace this morning. As planned, I started the car early, got it running on all four, and was therefore mentally ready to attack the circuit when the gates opened. I started to appreciate the top half of the circuit and get a feel for where the car needed to be, and even started to explore the limits of the car in a few spots. I had to work around slow traffic quite a bit, but I had a cracking good time and got out of the car after session 1 absolutely frothing and feeling on top of the world!!



So, it’s been a real rollercoaster ride. I’m leaving with some really fond memories, but also some unfinished business. I suspect I’ll be back.

Regarding the car issues.... Valve clearances are the prime suspect. The CarPassionChannel have done a video on this issue, and it seems to be similar to what I’m experiencing. I potentially have one or more valves with zero or negative clearance, meaning that they are possibly not closing properly. This means loss of compression on that cylinder, and failure to run properly when cold (valve not closing at all). The fact that it occurred when the car was on the track is properly weird, but I may have two issues on the go. Perhaps a dicky coil and a couple of valves with zero or negative clearance. More investigation required. I have installed new oversized valves. They may be made from a different material that has a different thermal expansion coefficient, or perhaps they stretch more when hot, or something weird like that. Again, more data is required. It’s all speculation st this point.

If anyone has installed 1mm oversized valves, please get in touch and share anything useful about valve clearances. If they need clearances that differ from standard, then I need some guidance.

In some great news, three of the guys from the Vic MX-5 Club picked up trophies today!! What a bunch of legends!!!

So, I’ve got a 10 hour drive ahead of me tomorrow to ponder the future. Questions like... What are the correct valve clearances for these new valves and the associated hardware... How fast could I have gone without the throttle and valve issues... When are my bloody camshafts going to arrive in Australia?!!!

For the record, my fastest lap today was a 3:00.2. Yep, that’s right, I didn’t crack 3 minutes. I told you... Unfinished business!!




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[plohl]

Not blaming anyone, but your engine builder should have done all the clearances.

Pretty sure the diameter of the valve is irrelevant, stem length is what needs to be known and accounted for, again engine builder should be all over this stuff.

Are you still using the standard shim on buckets?

I wouldn't rule out an electrical issue either. I've had issues with the adaptronic software, and it's been a software fault, so make sure you check all that sh*t again.

[greenMachine]

Agree with Plohl. Having run a full race engine, clearances, cam timing, etc all came from the builder. Your first call should be to him, to see what he can suggest. Can you give him data logs?

Your symptoms sound more like electrics to me, though have heard mutterings about Adaptronic software but not being a user can't really comment further.

I'd be looking at coils, connectors and wiring generally. If nothing, replace coils, pull injectors and have them checked (if you have spares, replace them too). Alternatively, talk to your dyno operator with a view to setting up a diagnostic session that replicates your start procedure.

I took a new car to Bathurst, and had a similar experience - mine turned out to be fuel pump.

[Magpie]

I'd be looking at coils, connectors and wiring generally. If nothing, replace coils, pull injectors and have them checked (if you have spares, replace them too).

I had a similar issues:

1. Shutting down for no reason. Turned out to be the CAS sensor. Replaced CAS sensor with a Haltech cherry red sensor, issue gone.
2. Wiring on one COP causing it to not fire. Rewired car.
3. Wiring on a single injector. Rewired car.
4. Programming issue that caused the COPS to be supplied voltage at the rate of 10hz (flashing) and not continuous power. Reprogrammed
5. Loss of fuel pressure causing engine protection to activate. Turned out to be a dodgy crimp at the sensor.
6. Feed fuel pump dropping pressure. Pump drew less current causing fuel pressure loss. Not resolved.

Can you log any of the voltage data from the ECU? Home signal?

Diagnostic tools like noid light, COP testers and Injector testers are very helpful.

https://www.plusquip.com.au/product/eqp ... ick-probe/


https://www.plusquip.com.au/product/eqp ... tor-probe/

[plohl]

Mark's post reminds me - the split ref and sync sensors on the vvt and other NB engines can be a pain. Specifically, the cam angle sensor (back of cam cover, intake side on the vvt engine). Both pham and I had issues - as I suspect Mark's issue was the same. The connector would vibrate loose, so you would get an intermittent triggering fault.

May or may not be your specific problem, but you can run a small cable tie around the connector to keep it in place.

What rpm does your engine idle at? Hot vs cold?

[Magpie]

The connector would vibrate loose, so you would get an intermittent triggering fault.

Thanks to John Pham for this solution. Tested the car with the cable tie in place and no more issues, replaced CAS with a cherry red version.



This is what it was replaced with. John Pham made up a nice metal bracket to hold it as well!

[1600Dave]

Looked good going past me on flag point 4 (the cutting) - congratulations on making it, huge effort !

Bathurst is definitely not an easy track to set great lap times straight out of the box. Thinking of heading back next year ? I wandered past your car a few times on the way to the showers but nobody was home each time - if you get reports of some suspicious character thoroughly checking your car out it was probably just me....

[The American]

Congratulations on setting a significant goal and achieving it. Nice work.

[StanTheMan]

The connector would vibrate loose, so you would get an intermittent triggering fault.

Thanks to John Pham for this solution. Tested the car with the cable tie in place and no more issues, replaced CAS with a cherry red version.



This is what it was replaced with. John Pham made up a nice metal bracket to hold it as well!

I replaced mine with an aftermarket one
https://www.bmotorsports.com/shop/produ ... ts_id/4310

Although let’s face it . A zip tie is a pretty cheap solution.


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[rascal]

Although let’s face it . A zip tie is a pretty cheap solution.

Even cheaper if you use a cable tie, as you don't have to pay freight from america to get one.
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(sorry, pet hate of mine.)