Turbo installed. Lasted 4 days. Threw a rod.
 

Riiiiiiiiiiight so I've just finished my turbo build. I got the car back from mapping 4 days ago and have just been doing finishing touches fixing hoses down and stuff.

I finished all that this morning and actually just felt like it was finally finished. Me and my mate thought it would be a good idea to film a super slo mo of the launch control on my iphone 5. Yeah well the video turned out great but then a rod pushed itself through the side of the block #fail

The car was only making 158bhp and 181ftlb at the wheels at 13psi on a hub dyno. I have 195 tyres and a 4.65 ratio diff so the engine really should have been waaaaaaay safe. The bottom end was completely rebuilt using genuine Mazda parts at a vert good local engine builders and had only done around 3000 miles since that rebuild. It ran smooth as silk with no knocks or taps. No smoke either. All seemed literally perfect.

I have a spare engine already :) but I'd like to know why has this happened.

I was actually watching the boost gauge when it blew up and it was just under 1 bar so it wasn't over boosting. Maybe it couldn't handle the launch control?

I imagined the diff or gearbox might go soon but not this. I'd like to try to figure it out so it doesn't immediately happen to my spare engine.

Anyone have any idea why this might of happened?

Here's the video ;)

knock/det causes a spike in cyl pressure enough to bend/break rods and anything else.

doesn't help at all that you were abusing it like a redheaded stepchild. (if you think anything about that launch was "safe" for the engine, you got another thing coming)...spitting flames out the tailpipe means you had all sort of unburnt fuel in the engine/exhaust/etc

Yeah I realise the using the launch control isn't exactly being nice to it.

It's mapped on ms2 and that's the launch control function. I have literally no idea what it does to make boost and flames as I drop it off to be mapped.

It blew after I changed into 2nd if that makes any difference? I was thinking the launch control could damage the gear box / diff but not really do the engine any harm. I mean I'm aware it wouldn't do it any good but I also wasn't expecting it to blow up with its first use.

cutting spark and/or fuel will absolutely put a ton of stress on the engine.

yours happened to not like it more than others.

I'm not blaming you, I'm just saying that when abused, even a low hp setup can blow up. And we don't even know what condition your engine was in and how safe the tune was (protip: just because it makes low power, does NOT automatically mean its safe).

Hmmm right well thanks for the input. Hopefully I can figure out what happened before I put my spare engine in.

Mechanical empathy woulda helped.

Ultimately though, I'd say it needed a better tune. When you say 'mapped' you mean you paid someone to tune it I'm assuming?

-Ryan

Hmm so much psi with so little power. You running a 1.6 with way too much timing or something?

Nope it was perfectly healthy 1.8 as far as I knew.

And yeah it was professionally mapped. I don't get involved with that at all. I didn't even drive it after I fitted the turbo. I picked my mapper up in my van and he drove it back to his with a base tune in it so he could get it there safely.

Fair enough with the people saying I should have been mechanically kinder to it but what's the point of having launch control if you can't use it? That's literally the first time I'd used it since the turbo was fitted.

Perhaps base timing was off? Did your tuner check it with a timing light?

Yes I seem to remember him doing that before he left mine.

I've taken the turbo off this morning and that seems fine. All the plugs look good so i don't think the piston has hit the head. It's no:4 that's gone there's a nice size hole next to my turbo oil feel line.

Once the engine is out I'll take a good look at the rod and see if I can see anything obvious.

Anything I should look out for?

Launch control exists in Megasquirts because ricer kids who abuse their cars asked for it. It doesn't make it smart to use, as you may have noticed. It was originally designed for highly built competitive drag cars using wrinkle wall racing slicks and oversized turbos. Is that you?

Since you have supplied no details regarding your turbo, tune, or plumbing configuration, I don't know whether your tune was garbage or not. A tiny turbo and log manifold with a very restrictive exhaust system could conceivably make that little power at 13psi, but it sounds like a tuning problem. Details on exhaust system? Log manifold? Catalytic converter? Piping diameter?

After listing all of the details of your modifications, take a screenshot of the spark table and post it here so that we can evaluate it for you. We'll see if we can help.

If you want to shoot flames without destroying your engine and related hardware, just buy an automotive flamethrower kit. AutoLoc® FLAME2 - Exhaust Flame Thrower Kit (Dual)

My setup is a log manifold to 2.25 down pipe and straight through exhaust with no cat. So yeah could be why power was down I suppose. Not sure on the exact turbo. It's a t25 but I'm not entirely sure which one. I know that apparently I need a gt2560 to make more power so I assume mine is the one below that.

Can't post my spark table as I said earlier I don't touch the mapping at all. Don't even have a lap top to plug into it.

With regards to the launch control, if my mapper says it's ok who am I to argue? As I said I don't touch the mapping and had no warning that the launch control would blow the engine in its first use. Also there are plenty if videos on YouTube of other turbo mx5s using launch control and not exploding so why would I assume that it's going to blow mine up?

im going with: you suck at tuning. you have no idea what you're doing. you abused it. you were asking for it to happen.

kicker guess: you're still running 87 equivalent octane.

pointing out retardation: you rebuilt a turbo motor using mazda parts that are known to fail with any abuse.

Did you even read any if this?

I didn't tune it. My mapper (a well known good mapper who I will not name as I don't believe it's his fault) was picked up by me and driven to my garage to start the car and drive it back to his safely where it could be tuned in the hub dyno.

I didn't build a turbo mx5 to not abuse it. It's clearly a toy and judging by the whole internetz they can take turbo power and abuse easily so long as it's done right (proper ecu, good cooling, oil cooler, ect, ect). My car was done right. Not a mega budget build but nothing was skimped on either. Mazda rods are not known to break at 181ftlb at all and it was mapped what I thought was safe.

Also running 99 octane super unleaded here in the uk.

Pointing out retardation: you should have read the thread mate.

Anyway back to some sort of constructive chat....

So no one else is using launch control on their turbo mx5s with standard bottom ends?

If it's as simple as that then happy days obviously I'll get launch control disabled with he spare engine.

Quote of the century after blowing up an engine on it's first go:

:bowrofl:

BTW, I've seen this happen a couple of times to people that completely relied on 3rd parties for MS dyno tunes. In both cases, there were two things in common:

1. Power was extremely low despite healthy boost. In the other case, a 1.6 making 135RWHP, in your case a 1.8 making 158RWHP.
2. Lifespan was short. In the other case, all four pistons pulverized by detonation on its first track session. In your case, well, you know.

What do we learn from this?
1. Det does not make power.
2. Det destroys engines.
3. Det is nearly impossible to hear on Mazda B engines. You need to be using det cans. I hardly ever see 3rd party tuners doing this.

So I should have had my car mapped at well known good mapper, then when he tells me it's all good I should have stood there and said no it isn't. Even though I have no idea about mapping. If I did I would have done it myself. But I don't so I took it to someone who is known to be good. As far as I'm concerned I did everything right?

If it does turn out to be a bad tune I will be very disappointed but I'm giving him the benefit of the doubt as I think he's a good guy.

Also he said he does use det cans. So hopefully it's not that.

Nobody said he's a bad guy, but we're not impressed by the tune. The objective evidence is hard to ignore.

Do your teardown and report back with some real information instead of emotion. We'll go from there.

So sad. I've track on N/A car on a base map tune, and my turbo car multiple times. Zero rod lossage.

Did you set base timing before giving it to him?

I did and I'm 90% sure he checked it before he drove it off anyway.

you, your mapper. semantics.

clearly it was not done right. clearly the rods will break when it's not "mapped" safe. To make you feel better: my first turbo motor lasted about 15 minutes because I did stupid noob things.

I dont need to read.

Can you post your tune? what are you on megasquirt?

I'm on megasquirt yeah but I can't post my tune as I don't even have a lap top to plug it in or anything.

So email your well known mapper and have him email you the files.

Did you properly break in the motor? I have been told ( with my other fully rebuilt motors) to initially drive it hard ( a lot of deceleration in gear) with very little idling to help rings and bearings to seal properly. It has also been relayed that a fresh build also use dino oil first then change out after 100 miles then again at 2k-3k depending on amount of metal shavings. If that 3k miles was babied then I can see how a rod can be poking out of the block after a launch like that.

Wat...

Our engines don't like as much spark angle as Hondas and Nissans because they are different engines in design. If the fellow doesn't do a lot of B-series Mazda engines, he should stick to the base tune's spark map that can be downloaded from DIYautotune and a few other places.

Out of curiosity, what RPM was it set for when you were using the launch control?

OP, I feel like this thread is going to go nowhere until we actually get some proper info/pictures.

Your: "hai guyths, my car borked, it was done right and low power, wut happened?"

Us: "well, I'm guessing........and..........and.........and based on...........and according to what you said..........and"

We're just guessing. And making assumptions based on the very little actual info you provided.

We need to see the tune.
We need to see the carnage and close ups of affected parts (good pictures of spark plugs, piston tops, etc)

Only then will this discussion become truly productive.

A 2554 or smaller with a small A/R turbine housing, a log manifold and tiny exhaust could conceivably create enough restriction to be that bad, but you'd really have to try.

in for spark map and logs.

sorry to hear this OP, this type of thing pretty much never happens unless something was fubar'd on your end.

What injectors did you have? were they flow tested?

I'll post some pics of the hole in a moment but that's all I have. I haven't removed the engine yet so no pics of pistons or anything. I did removed the plugs today and they all look perfect so I don't think the piston has contacted the head. As soon as I've removed the engine I'll take the sump off and take some pics.

550cc ev14s they wee not flow tested as they were second hand but the plugs all look perfect so I reckon they were working fine.

I know he's away all weekend but I'll ask him when I speak to him

He is a mx5 specialist. Well known on these forums that's why I trust it's not his tune.

Rpm was set to 4500 for launch control I think.

Yep it was broken in correctly and worked perfect. Great compression and no oil usage.

Well, it could have been the engine assembly or maybe it got overevved at some point, but if it happened when you were using launch control that's probably the culprit.

Super curious what you did to destroy a motor in 15min, Id like to keep from making the same mistake here in a month when I put my turbo setup on

Horton, same engine as the one in this thread you made ?

https://www.miataturbo.net/general-m...rebuild-78604/

you ever solve the issue with cylinder 2 ?

had timing advanced 16° form when I was n/a.
had 87 octane still in tank.
boosted 7psi.
only had a 12:1 FMU for more fuel, but no timing retardation.

Det to destruction; blew out ringlands on 2 pistons.

surprised that your retardation didn't compensate for lack of timing retardation

:D

https://www.miataturbo.net/engine-pe...-rating-78590/

Yes mate same bottom end. The on heavily skimmed head as the issue on cylinder 2. Didn't smoke at all or burn and oil (hard to tell in 4 days tbh) with the new head and turbo fitted.

Also changed the plugs out for correct one suggested for turbo cars.

I had a big list or all the things I could think of that a turbo car needed and mine had everything expect a coolant re route. Which I have most of the parts for just haven't fitted it yet.

Cool video by the way!

Right I've taken the head off and removed the piston through the top by super glueing a little sucker on the top of it.

Here are pics.

Pic of no:4 straight after I removed the head. The piston has hit the valves in the head.
https://www.miataturbo.net/attachmen...ine=1408965497

No:1
https://www.miataturbo.net/attachmen...ine=1408965497

No:2 & No:3
https://www.miataturbo.net/attachmen...ine=1408965497

Mangled rod:
https://www.miataturbo.net/attachmen...ine=1408965497

The bit of rod left on the crank spins perfectly smooth so I don't think this is bearing related.

Once I've got the block out I'll remove the sump and take a look at the bearings in what's left of the rod.

Here's the launch in normal speed.


I held it on launch control until I saw the boost rise on the gauge the let it go and released the clutch. I'm pretty sure it was a full boost when I let it go or at least very close.

So maybe it just couldn't take a full boost launch? And there's nothing wrong with the tune?

define full boost. did you post the tune yet?

can you show pics of the head in a similar manner?

Looks like a big chunk of piston is missing on #4 on the intake side and some det on the exhaust side of it. And maybe some contact with valves.

Lots of compression getting past the rings, but unsure if that was before or after boom. Probably will find a cracked ringland on the piston.

All four show it was running pretty rich, as the pistons are steam cleaned from the fuel.

Full boost as in I watched the gauge get to just under 1 bar before I let it launch.

Can't post the tune until I get it off my mapper

The head does have marks on the valves where the piston has hot the head. The engine made good compression a couple of weeks ago.

Also I have the no:4 piston out and there are no signs of cracked ring lands or anything that I can see

Really interested in hearing more feedback/opinions and seeing that tune.

I'm certainly no expert, but those pistons don't look bad to me at all, definitely not like I've seen from other motors that met an early demise. I assume we can ignore the valve marks on piston #4, none of the other pistons show any damage and with an exploded rod it seems pretty inevitable that there would be a collision.

The problem is, it still could have been knocking badly, and you wouldn't see it too much since he's only had the car running 4 days. So while I agree the rest of the pistons don't look too bad, we still can't rule that out.

But for all we know it could have even been a seized injector that flooded the cylinder and hydrolocked it.

Sitting on the 2 step and building just under 1 bar is putting some serious stress on the engine. Even built engine cars I've worked with don't do that.

Serious heat and load from sitting on the 2step + possible flood from cutting fuel and spark = boom?

Really it doesn't matter without knowing the state of the tune (probably garbage), but really this is pretty cut and dry, due to numbers.

1) The motor was fucked before it was even turbo'd.

or

2) The tuner sucks.


Or a combination of 1 and 2.

The motor made great compression and ran perfect before the turbo. It also ran perfect with the turbo. No smoke, no rattles, no knocks. I had my local engine builder (who built the bottom end) take a look at it and he said the pistons look great. The tune appears ok but hard to tell from just 4 days. He thinks the rod simply couldn't take the stress from the launch control simple as that.

I personally think the tune is fine and that the launch control was just too much. I am still confused as to why it made such lower power for the psi the turbo was producing though.

rods break from torque

your engine doesn't make much torque.

the only thing that could have spiked compression through the roof like that is a bad tune or failed injector or something

until you post the tune, I'm betting everyone will just say its the tune

These statements are contradicting.

Are they? I mean it appeared to run. Perfect and I was told its running perfect just not making great power.

If it was running perfect, it would have made more power.

Whether it was running like dick due to the tune, or due to a shot motor, we don't know. But it wasn't running well.

You're gonna get seriously flamed if you keep saying stupid stuff like: " It didn't go up in a burst of fire on startup, and I was told it was tuned good by the guy I paid to tune it, therefore it ran perfect and was tuned perfectly"

I mean seriously.......stahhp

*edit: and I keep forgetting to mention that if you really have a 4.65 Final drive, your 1st gear is semi-truck long, meaning you probably didn't load up the engine that bad after you actually launched it.

Right.

No tuner is going to say "Thanks for the money! I did a fucking terrible job for you, have a nice day!"


At least... not to your face.

Also see: TDR.

if your going to ask for help you need to keep an open mind. don't be an ask hole or you'll need a flame shut....



Shamess plug--> fire suits available at OGracing.com :P

I don't know much about BP motors, but if you messed up a rod it happened from pre-ignition. Ie two cylinders firing at once. things that can cause this, too lean, excessive spark advanced, elevated cylinder temp, faulty coil wiring ect...ect...ect . post pictures of the cylinder head and spark plug. that will have evidence of Pre ignition.

Exactly my point. 160hp for 13 psi is nothing. Should have been in the 220-230 range.

LOL

But gaiths, the car ran perfect. It didn't blow up for a whole 4 days. That's like...forever :party:

So how much timing and fuel enrich was it running for the launch control?

OP, just as a reference point...

Here's a 2554 on 10psi.

https://www.miataturbo.net/attachmen...ine=1408979180


For another anecdote, that car has run for at least FIVE days.