Turbo reliability: What has broken? How can you prevent it from happening again?
 

I had a turbo Miata in the past, which was known for its tendency to sit around broken...

I'm thinking of starting down that path again, but I'm not sure. I know at least one person who has given up on turbo and gone back N/A for this reason.

So, what have you broken? How can you stop it from ever happening again?

Don't cheap out on important parts.

It's all in the tune.

Mechanical Empathy.

Check your shit frequently, once you mod a car, it is no longer a "set and forget" deal.

No problems here. Just make sure you do it right.

Do it right the 1st time around with good parts and take your time putting it together so you don't forget stuff. Tune it well and don't dare beat on it til its tuned flawlessly. Know your setups/engines limits.


Or be a giant PUSSY and go back to n/a:D

I don't understand how anyone could go back to a NA setup after going turbo. If anything, the only way to go would be to a completely different car.

That or a v8.

I had a supercharger for three years, about 170rwhp... it was one issue after another. got tired of having to screw with it and decided to build an N/A motor. don't have to touch it unless I want to and its an absolute blast to drive.

While not a turbo, I could see why someone would go back N/A. It's a fraction of the power many of you have, but still have little opprotunity to use it all on the street. It's certainly not slowing me down.

This.

If you actually think about it, a decent turbo system on our cars (200hp), 1st and 2nd are near worthless, and you can use 3rd gear for what, 2-3 seconds before you're driving over 90% of the speed limits in the country?

Not that I'm saying I never drive over the speed limit or at least accelerate like hell up to it, but I could definitely see why someone would go back to N/A. I am right now while my injectors get cleaned, and although I have 5psi way up at red line, it's still a blast. For the track I'd STRONGLY consider N/A, I consider it a pretty big mistake going turbo on my track car. Too much money is required to make a reliable turbo miata track car. Kinda too late now though.

With that logic we should all buy civic hybrids and Priuses so we can "USE IT ALL ON THE STREET"

No thanx

Yes, you could probably floor it through most of the gears on a Prius and a cop next to you wouldn't even notice. And obviously turbos are still really fun on the street, I love mine. However, in order to realize the full potential of a turbo, you must either be an idiot on the street, or take it to the track. That's where there's a huge jump in budget required, that's all I was trying to say.

Once you add a turbo, you also have to add the discipline of restraint. People don't like discipline.

Neither of my turbo miatas have been less reliable than the n/a miatas I had before them.

Qft
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Stealth, reliablity issues from a S/C kit? .......... damn (thats not a knock on s/c kits, just haven't seen many issues with them)

I fully believe a street driven turbo car with quality parts and a good tune can operate just as reliable as a N/A car. But like they said, it's not a set it and forget it system anytime you mod a car.

I believe if my engine would of been assembled correctly my car would be running fine. Kind of ironic I've got some ITBs sitting in my garage lol. I think I'll end up giving them to my dad who loves the old school ITB theme for his weekend toy. I can't stop thinking about my next turbo system, how much it'll cost, how and when I can obtain it, and the next local track events lol.

Ah, well that makes a lot more sense.

oh hell yeah. Comes from running a JRSC at 11 psi when intended for 6. it was a belt shredding, idle dropping machine. The only things it did well is smoke tires and scream like a banshee. I loved the sound and the power, but I just want to drive the thing. It's actually a hell of a lot more fun to drive NA... yeah, I would not believe you if you told me that either.

Coming from the person running a supercharger :P

Well, let's see:

1: My left door speaker has stopped working recently. It may be due to the rather significant amount of water I intentionally blasted past the seal and into the inside of the door to clean out whatever road salt may have gotten down in there. Haven't yet disassembled it to inspect.

2: One of those white plastic things that are stapled to the carpet to hold it onto that ridge at the rocker panel finally tore off. It'd been loose for some time, and the last time I pulled up the carpet to access the ECU, it came off entirely. Not sure how I'm gonna fix that...

3: The larger of the two rubber boots around the shifter is torn... again. I doubt that I can ever stop this from happening entirely; just keep replacing 'em.

4: I snapped off one of the two bolts that holds the thermostat housing to the head. Not a big deal as that hole is capped with a freeze plug now, but it still annoys me to know it's there. No fix is possible on this one, as the broken bolt also has part of a bolt extractor broken off inside of it.

That's just about it, really. This car has been turboed for about four years now, currently running ~ 14 PSI. The clutch just recently started slipping, but that's hardly surprising as it's only an ACT HD in the 1.6 size. It's a wear item that's worn out.

Apart from that, no drivetrain difficulties. Engine and transmission are bone stock. If you take care of 'em and don't do anything stupid, these little bastards will surprise you with how tough they are.

Mechanical empathy is pretty much everything. I've broken basically everything on my car, but I also beat the everliving piss out of it. Use quality parts, check them often, keep up on your maintenance, and always upgrade if something does break.

Apparently no one has ever preventably broke anything on this forum. Well, hopefully this will be useful for someone to read.

What they are all trying to say is that if your running 20 psi on a stock engine, your gonna break stuff, 10 psi done correctly not so much. 10 psi with bandaids, you will break stuff. How much stuff you break is up to you. You never did specify what your goals are, perhaps being more open in that area would help us tell you what you need to beef up.

Beside a motor? not much, I blew out a coupler once. Everything else that has failed or needed repair was fault of my superior mechanical abilities.

That's not relevant to the question that I asked in this thread. If you're not posting what broke, and how to prevent it, you're not doing it right.

Read my build thread and SavingAIDS' build thread. I'm by no means the fastest guy on here, but I've had my share of reliability problems on the track, but I've been through a few major problems and everything seems to work now aside from the brakes.

Stock 1.6L clutch started slipping after about 10,000 miles of "nice" driving at 8psi.
Replaced stock 1.6L front brakes with 94+ caliper brackets, aftermarket discs and pads
Getting ready to replace stock 1.6L 6" rearend with 7" 94+ rearend so I can "launch" car
Smoked one stock NB O2 sensor running lean/pig rich with my "bandaids"
Smoked one AFM when re-installing turbo & intake piping (my dumbass mistake, not turbo's fault!)

If I had it to do over again, I'd probably start with a 94 or 95 (1.8L base with bigger brakes & rearend) and immediately install a Megasquirt, big injectors and a wideband. Once I had the MS sorted out and real solid NA tune, I'd do an Ebay Chinacharger with a CSX Racing intercooler kit. YMMV.

My 250k mile Torsen differential after fresh bearings, apparently didn't like being launched after I installed the turbo...kaboom.

Most of the stuff on my car that has broken was just stuff that prob needed to be replaced since it has 262k miles on it, only thing mechanical left that is stock is the transmission and axles.

My OEM clutch gave in at 8psi. Other than the occasional hiccup, no issues.

Well, check out the attitude on the new guy. :D

We don't keep a lot of secrets around here. Folks have turned their diffs into metal salad, bent rods in all three axis at the same time, cracked pistons in half, poked holes in the side of their engine block, etc. I don't think I've seen any cranks which were actually broken in half, but that's about the only thing I haven't seen.

But like Sav said, it's mostly about not being an idiot. If you run a 1.6-size R&P, or if you do drag launches, then you'll break your diff. If you don't do these things, then you won't break your diff. Simple.

Likewise, all the piston / rod / block failures are mostly due to stupidity. Bad tune, inadequate fuel system, too much boost, etc. If you built it to last, and tune it to last, it'll last. If you cheap out or do a hack job of it, expect to see Mr. Rod open a window for himself in your engine.

This ain't a big mystery.

My current motor has some dead ass rings on it, and is chewing through a quart of oil for every tank of gas.

Solution...don't let your dipshit brother borrow your car.

In reality this is mechanical empathy. I know my car, know my tune, and know how hard to push. He didn't...and treated it like his sportbike.

Every other problem was fixed with some datalogging or changing settings in MS.

The first motor in this car died of overheating. Fixes on that are well documented. It now has a PWR radiator, coolant reroute, and some shrouding. Soon to have a hole in the hood.

shouldn't have blown if the tune was good regardless of abuse...

The only part of the tune I fucked up on was leaving the soft rev limit at 7200rpm.

I though my tune was bulletproof as well...but he admitted to "very high rpm" usage. I'm expecting to see a lot of nice, shiny, blue metal parts upon postmortem.


I hear ya though, and am still scratching my head. To be honest it was a mystery motor anyhow ($150 CL find), and I imagine that the rings were already heading south. As compression gradually got worse, the motor saw higher cylinder pressures for the same load....rendering my previously conservative spark map dangerous.

When he brought it back my OP gauge was dancing around, and there was audible knock where there previously was none. I've dialed boost control back down to 8psi, and the whole spark advance table back 15%. Now everything is fine.


I guess you could say that this could have been prevented with a higher integrity motor, and that we should occasionally run a compression test in order to prevent damage due to detonation. I think the motor went into a nasty cycle of light det>chewed up ring lands>lower compression>more det, and numbnuts kept wailing on it.

:giggle: (seriously those belts would drive me insane)
Nobody here is retarded enough to shit out a random psi figure and say to stay below that.

Update: My alternator bolt backed out today. Damn turbo.

When I was N/A had to replace the axles, alternator, timing belt and by then I said what the hell and installed fresh piston rings and rod bearings. A few days later took the cylinder head to a machine shop for some well deserved cleaning now that the engine had been opened, and a new water pump on the works. A few more weeks later and a new clutch and pressure plate with resurfaced lightened factory flywheel, Oil catch can, new sway bar poly bushings and poly mounts.

By then the starter and clutch slave decided to not work anymore. As time passed by the rear struts were useless which one visit to the junkyard made me discover KYB struts in another Mazda.

Since I have gone turbo WITH bandaids, ready or not here it is... An APEX SAFC, Innovate wideband and the low budget DIY Knock sound amplifier, my only problem has been a ghetto worm clamp which has been replaced with T-Bolt clamps, so far car is running fine for about 4 months now at 10 psi.

I do agree that sometimes I do miss the N/A setup, before it felt like a go-kart that I could toss around and felt with much more control on its powerband, now its like a little beast that in two shifts I am already over the speed limit, but still it is a lot of fun to drive as well.

BUT on my first setup I blew two engines with a Rx7 turbine with a swapped turbo housing to .48. It would always blow the piston rings of 1 and 4, and ate up the Stage II Centerforce clutch.