This thread is awesome!

No, bro, stay the course! It's totally common for all four rods to bend like that, happens all the time.

yeah, these cars are so gay, even the rods aren't straight.

:giggle:

My guess is a spark cut flat shift into second, flooding the thing. Looks like it was rich as hell to begin with.

Why cut the video short, did you really only record 4 seconds of video? I want to hear loud noises, Booo...

Subscribed to see this tune.

https://www.miataturbo.net/attachmen...ine=1409440075

I told you how it could happen. Cam timing being off plus launch control. Or tuning is off.

Something to consider is that the spark timing is tied to the CAS and if that cam is off a tooth or two related to the crank then your very safe tune becomes insanely dangerous. If the tune is only marginally safe then things get to be much more interesting with only a minor cam timing mistake.

It could be the tuner or the engine assembler at fault. Find someone who can download the tune from the MS other than your mapper and post it here for an analysis. We've done this before and can ease your mind as to the underlying cause.

Right…

This is clearly one of those scenario's where the internet has been given part of the information and run with what's assumed by that.

I tuned this car

For those in the USA who aren't aware, this isn't my first rodeo and was a standard job - Connor is a customer who I get on very well with and things like collecting the car from him was done due to that relationship, to help him out rather than him finding a trailer etc.

I've tuned more cars than the majority of this forum as a fact. I subcontract as a tuner to very well respected companies locally & internationally and tune everything from low level, high revving NA race cars to 1000bhp+ drag cars, running every different type of fuel available on a range of management systems. I offer E-tuning services internationally and 80% of my income is from tuning. I've tuned a large majority of the UK's higher powered MX5's and have installed and tuned countless turbo setups on stock BP engines. Connor's car was routine.

The car was tuned on a DynaPack hub dyno [Abbey Motorsport, Surrey, UK] with a Plex tuning knock sensor fitted and Motec PLM fitted to the downpipe. As part of my tuning routine I intentionally cause a knock event at low rpm & low load to ensure that my knock hardware is working correctly. This doesn't cause harm to the engine and means that I can be 100% about my tuning. A manual fuel pressure gauge was fitted and checked on throughout tuning.

Connor's car has a HKS hybrid setup with the smallest T25 turbo available - it's fitted with a .3bar actuator, the most restrictive down pipe I've ever seen [read as small bore, down pipe can only be described as 90 degree point into 2.25 tube]. He also has an intercooler that creates .3bar of boost drop at actuator boost levels - meaning that at 6kRPM the ECU actually saw 102KPa when on actuator. The complete setup was supplied to Connor second hand extremely cheaply through a UK forum from a chap that Connor himself has described as being "a lovely guy but a complete idiot". The injectors are 550CC EV14's with spacers fitted but no gauze filters.

Base timing was set before leaving Connor's and again at the dyno.

Connor's car has previously been run NA [numerous posts about issues with this engine by Connor on this very forum, including seizing a cam in the head last month]. It's previously been run with a limiter of 7.4k - I have stock rods in BP running at 7.75k limiters in some of my track cars, but they're all NA applications. Connor's car gets drifted and abused more than most - hence why I'm careful tuning it.

Currently the limiter is set to 7.2k.

With the MS controlling boost through a Pierburg solenoid I was able to make the boost I needed and by running at .3bar the torque curve showed a perfectly reasonable shape for a BP engine [if cam timing was out, it would show here].

Onto the final tune.

The car struggled to make boost up top - initially I thought it was due to the wastegate being blown open but I lockwired the WG shut for a run on the dyno and couldn't get it to generate the boost up top. Based on my notes the final runs looked like this:

160KPa @ 3k, 190KPa @ 3.5k but dropping to 170KPa @ 4.5k, 165KPa @ 5k, 160KPa @ 5.5k, 155KPa @ 6k to redline.

Boost was left controlled open loop due to the wide range of duty cycles that caused PID wind up when left in closed loop [I'm sure with hours of tuning CL would work well, but this was not meant to be his final setup so would be wasted time].

I don't have access to the dyno graphs right now but I'll post AFR, boost and all the graphs over the next couple of days [I'm on the dyno there for the next 3 days].

I tune in Lambda, so I'll just give a rough idea of my targets below:

up to 80KPA - Lambda 1
100KPa - Lambda 0.95
110KPa - Lambda 0.9
130KPa - Lambda 0.825
150KPa+ - Lambda 0.8

I use these as a starting point, but Connor's car was tuned by those.

Connor's car made 181.5ftlb @ 4.2kRPM with roughly 180KPa, it made peak power 157.8bhp @ 4.8kRPM with roughly 165/170KPa. If you compare those figures to other graphs there was nothing out of the ordinary other than the lack of power up top.

So back to his broken rods…

He utilised launch control - which was set at 4800RPM, using spark cut. Soft limit zone 300rpm, soft retard to -20, enable launch above 10% TPS.
I tune launch on the dyno [for this car, where wheel speed is not referenced and I'm able to do so]- I setup a dyno run starting at Launch RPM, ending at redline with a time of 2 seconds. It's held until triggered by pressing F3 [DynaPack tuners will understand this].

This allows me to build boost using the launch limiter and release the launch button at the same time as starting the run - Connor's car made more boost on the launch limiter than it would on a standard pull, which makes this whole routine worth while - this part of the map was therefore checked over and although I don't have the exact figures to hand torque was no-way near the safe limit of the BP engine [On this dyno I do not tune stock BP's past 215ftlbs @ the hubs].

I've pulled my hair out about this over the last few nights as I've been in contact with Connor, it was only late last night whilst I was out socialising that Connor made me aware of this thread. I've been down the workshop and pulled the MSQ from the server and it's attached below - I'm open to hearing your views.

Once the car was off the dyno the conversation was had to Connor that the restriction up top needed to be sorted to make more power, I recommended a GT2560 turbo and changing the downpipe/exhaust setup - with that he'd be able to make 210ftlb to redline and have a noticeable increase in performance. This is the reason that I didn't waste hours tuning the closed loop to deal with the huge duty cycles needed and also why this was so routine.

I personally think that at some point whilst NA the car has slightly stretched all 4 rods (either through over rev or the 7.4k limiter) and once turbo charged, the extra load put through on the launch control has caused that weakness to become apparent. Connor and I get on very well and I've often made tune tweaks to his car free in the past, spent plenty of time offering him advice on parts of his build and will continue to do so. I'm happy with my work and honestly do not feel the issue is due to me - I know I'm going to hear from you all shortly, but read the above, absorb the information and make informed comments.

Daniel

Well written post. Gotta love working with cars, when shit hits the fan it is always a shit fest.

Well that certainly sheds more light on the situation.

Thank you Daniel, for taking the time to break things down.

I'll check out the msq when I get home..

True, but OP also wasn't giving us any info regarding the "mapper" besides saying that he's well known and he doubts that its the tune. That was a very big variable left to just kinda "trust".

Here's screen shots for those too lazy to open lol

https://www.miataturbo.net/attachmen...ine=1409512438

msq doesn't look bad.
at least nothing sticks out at me....and if something does, its how much fuel is being pulled past 6300

Just what it wanted on the dyno once into boost - hence the comments to Connor about a larger turbo and better downpipe/exhaust setup. I'd usually run more timing through past 6.3k than this car wanted which told me at the time that it just couldn't flow at the top.

Thanks for the comments so far

Definitely. I didn't really mean anything towards anyone in this thread. Just that with cars it is always (well some times) hard to figure exactly who is to blame. Thus the impending shit fest. Anyways glad there is some good info being put out now.

Looks like a pretty safe tune, conservative spark table.

Good luck working it out. That engine needs to be uncorked. Well, at this point, discarded.

You might want to adjust the "Req Fuel" value (basically cut it in half and double the VE table). As it is now, you're leaving half of your available fueling resolution on the shop floor. I've never found MS's built-in "Req Fuel" calculation to work particularly well. Always ends up giving low values in the VE table (each VE cell can be between 0 and 255, so if your max values are ~100, your Req Fuel is too coarse).

I didn't realize how bad the "req fuel" calculation was in the megasquirt until I swapped injectors... with a good req fuel calculator and an injector swap you should need minor tweaks to your fuel map at most... but with the MS system you need to do a full re-tune. Either that or I fucked it up :)

Will changes in the required fuel effect other tables like warm up enrichment, Accel enrichment, and other things or is it just the VE tables it screws up?

Keith

That's not an issue with the req_fuel number, it's merely a characteristic of your injectors.

Not so sure on that, people stopped responding in that thread.

With the required fuel adjusted for 1000cc/min injectors I had to add +60 in all areas of my VE table and start a full re-tune from that base. If it was a non-linearity problem I would have only had to add a crap load in the idle areas of the map, and leave the rest alone. When I tried that I was dead lean at anything above idle, so did the "better safe than sorry" start rich and let the VE analyzer live lean it out method. Now, if I end up with values that are about the same at cruise I will have to put it down to non-linearity. I can't check the "high load" stuff because high load used to be 100, now it is 180 :)

Keith

req_fuel is a multipler. the end.

if he doubled his req_fuel, his fuel map would drop in half.


Horton has ~460cc injectors installed? n/m i see 560cc ev14s.

Don't believe it if you like, but req_fuel (called base fuel in other ECU's), is just the starting point in the fueling equation. it's just a number that's multiplied.

PW = DT + (ReqFuel * MAP * VE[RPM,MAP] * AirDen * BaroCor * corrections)

With any other injector, you do as you state, chance the number and a minor retune. EV14's behave considerably differently.

I don't see the big deal though, really how often do you change injectors?


You're disagreeing with me, but haven't even seen an end result yet? You know your injectors are linear, yet you've not actually tuned the table yet to know whether they are?

Okay.

I believe I have 550 injectors

I am not trying to be a dick here. I admitted in my thread that I am not sure how this works with these injectors... and people stopped responding to my questions so I stayed lost rather than getting it figured out.

And sorry for the thread jack, but I am getting answers here that I didn't get in my injectors question thread.

Because I went from having max load 100 (being naturally aspirated) to max load being 180ish now with the turbo it is hard to see how linear or non-linear the injectors are, I will take everyone's word for it.

Now, this non-linearity would effect warm up enrichment since that is at low pulse widths, but not effect acceleration enrichment since that is normally at higher loads... correct me if I am wrong. Should I make changes to the warm up enrichment?

Keith

PS: really am sorry for the thread jack, but the required fuel subject coming up brought this issue to mind.

WUE is on top of VE. And ASE is on top of that. So, no. Look at the equation you quoted above. Corrections are in addition to VE and REQD FUEL.

Well the timing looks great. With this confirmed, this is standard scenario of a skipped tooth on the timing.

I'm content with the tuner's response. Thorough and professional.

I don't think the engine slipped a tooth. I think it slipped a whole cam.

Which cams were in the car when the rods bent?

Standard cams were in the car when it died. Along with a completely standard head.

The spare engine is in and running. All seems well. Touch wood*

Dan will be checking the map on the dyno next week just to be safe. I'll drive it there gently. Hopefully this will be it sorted.

It appears I may never know what happened to the other engine.

You should knock on wood, not touch it :giggle:

There are theories........But yeah, at this point its near impossible to figure out 100%

*rub wood

LOL. props

You are in good hands.

You might consider leaving the launch control off just for long term fun moving forward.

Yep I've disconnected it from my handbrake and I'll just leave the button alone ;)

This story might have a *happy ending* after all

I'm unsure how to answer the above.

Anyone else notice that the guy who made the video did a cut and past on the eyes? They are completely identical.

How lazy do you have to be to only draw one eye on your "art" and then copy and past it so your creation isn't a Cyclops?

Keith

Maybe he wanted 2 same looking eyes instead of a crooked eye beast?

about as lazy as not spelling out "paste"

:giggle:

"common breh gimme a break I was driving when i typed that"

Mechanical over-rev OP. Shift like a gentleman.

Don't feel like it over revved once. If anything it barely saw the limiter once turbo'd

I think the assumption is that you over reved it when it was NA and you stretched the rods which weakened them. Once you turbo'ed it the extra torque and abise from launch control finished the job.

Ah I see. Well I can't remember ever getting a shift wrong but it did get drifted on the limiter an awful lot so could have been that

This time put the limiter at 7k.

Yep I'll ask dan to lower it when I'm at the dyno

Been on the dyno today.

Made more power and torque. Very happy with it now. A MASSIVE thanks to Dan at ardler automotive for checking the whole map over of me again.

Rev limit lowered to 7k

Hopefully it last more than 4 days this time.

Attachment 184704

Attachment 184705

If any of you are on Instagram follow me on there for more pics

Username: connorhorton

That's...uh...a funny looking torque curve.

Holy shit, it's just like looking out the window of my house (a mountain).

not loading for me. i hate photobucket.

So the car went on the dyno again today, it instantly made better power and needed work to the fuel map (especially in boost) to get it where it needs to be.

The strange torque curve comes from the same flaws in the original turbo setup where it just can't make the boost at the top end. It does however make for a lovely flat power graph at the top (I'd much rather have flat torque to redline but not many people run big enough turbos on stock engines). It's also emphasised by the way that the DynaPack auto-scales it's axis, which makes small changes look rather… large.

All in all - it's back on the road and the iMessage from Connor a short while ago that said "It's sooo much faster", it's amazing what an extra 20bhp can do :-)

Daniel

It's nice to see the dyno runs start at a nice low RPM.

With that torque curve you should have set the redline at 6000 rpm. He's got no business revving it out any higher than that with that clogged exhaust. All that it will do is make excess heat and cylinder pressure above there, and maybe cost him another engine.

After seeing that dyno I would be concerned the cause of the original failure still lurks within the new motor. That type of torque fall off means you got one hell of a restriction somewhere. Restrictions like that cause cylinder temps to really skyrocket and lead to detonation.

I would pull the exhaust and dyno with just a downpipe and see if anything changes.

Diesel swap?

The cam timing is off. Im calling it. Im sure its been said before, but seriously, the mechanical timing is advanced a tooth somewhere.

So...what PSI is that at?

That's fucked. It's dropping torque worse than a stock msm.

It's gonna blow again.

The exhaust really isn't very restrictive at all. The down pipe is the standard Hks on that's been chopped and made to be more free flowing but it does have a pretty sharp angle off the turbo so that must be a restriction I suppose.

Still at 13psi.

Cam timing is not off.

Torque really doesn't feel like it's dropping off that bad

I'm sure dan will answer with a more technical answer

There is a problem. Look at all the dyno plots posted of our cars, none of of them look like yours.

None of them choke down like that. Even the ones with stock exhaust don't drop to 100tq @ redline

omg, someone post the actual images here. photobucket never works for me.

this is his torque curve: /\

literally drops from 200 too 100 by redline.

It doesn't matter what it feels like when we have a graph. Graphs don't lie unless they come from Australia, so we know something is wrong.

Are you using a catalytic converter and stock muffler?

I see it now; drops 80rwtq from 4K to 6.8K--I hope his boost at redline is 90kPa. That or I'm still sticking to my original theory: the tune.


I cant see how 150rwhp once it FINALLY spools to redline can feel good...

Typically when one makes 200rwtq, you'd expect at least 230rwhp. What turbo is this?

No cat at all. Straight pipe from the turbo back to a single straight through box at the rear. All of it 2.5"

It's making 10wtq more at redline than my motor did...


WHEN MY MOTOR WAS N/A.

http://forum.miata.net/vb/picture.ph...&pictureid=994