MSM IHI turbo failurs at what boost pressure?
 

Does the MSM IHI turbocharger have a known failure point or mode when pushed very hard?

Thanks,
Dann

Yes, anything above 5000rpm it fails to make power.

I think you mean torque.

I'm running one at 15psi and just wondering if the compressor is going to shatter?

Dann

No, power.

No, it won't shatter.

Power holds flat for all of rpm's, even at 8k. You mean torque.

Thankyou for shattering info. Making 230/230, Pretty happy with that for such a tiny turbo.

Dann

Anyone concerned with making power on a MSM swaps out the turbo long before maxing out the stock IHI....lol

I'd imagine anything above 210-220 rwhp, the thing is blowing mostly hot air and is long out of the range of being efficient....meaning any turbo designed in the past 10 years would be a better option.

Yeah Ive been putting together some bits to see what it takes to make the MSM worth modifying.

Front pipe back 3", intake, TBI, ebay intercooler and tune seems to make it worth owning. Im just concerned that there might have been issues running the little turbo this hard, in terms of turbocharger failure.

Dann

Yup, I really do mean power.

https://www.miataturbo.net/attachmen...ine=1430490760

Torque is always going to go down with RPM, especially with this small of a turbo, I'd expect that. But I'd ideally want power to continue to climb, or at least flat line. The above graph was with 3" exhaust, basically zero muffler, and that includes getting rid of the restrictive cast iron DP elbow off the turbo. Giant Evo intercooler, big injectors, VICs, and an MSPNP2. All shoved in a '92.

Stock MSMs are very worth modifying. A decent downpipe and exhaust, and they'll sound amazing. Intercooler is just for consistency during constant abuse. You'll most likely want a clutch for the drivetrain, otherwise it's great, beyond a shitty 4.1 final drive. You're just in the range of needing forged rods, we bent stocker with a season of abuse at 225hp and 235ft/lbs, which stock rods should handle, but we beat the crap out of it and torque hits hard and fast.

Injectors should be the first mod after you upgrade the ECU, which is mod #0.

I'll be playing with another MSM soon, but the only issue we seem to have is fueling. Of the two MSM engines I've played with, one in the '92 and one '05, the '92 had incredibly stable AFRs, while the returnless '05 had fairly tricky AFRs, I tuned it a little rich, since consistency between runs wasn't great. Don't get me wrong, it left with a decent, albeit slightly rich tune, but it kept me from being as aggressive in my EBC and timing tuning as the above graph. Which I don't think is horribly aggressive.

I should note, that on one run EBC was disabled and acted as a closed wastegate, I need to fix that. However, before it hit boost cut, it made 251ft/lbs by 3850rpm.

Fails at 15.1psi. 15.05psi is fine.

I ran mine around 11-13psi for about 50k miles since I installed my ms2e and the seals went on me a month or so ago at 105k on the car.

I made a little over 200hp, boost pressure started falling flat on it's face after 6k rpm. Good midrange grunt that's about it. I think 15psi is a little much without meth injection or something. If I hadn't been tuning myself I think I could have pulled some better dyno numbers out of it.

While dan is correct in theory the turbo is going to sit at more or less its peak flow and power wouldnt drop if VE didnt drop, but the natural VE is dropping off so power is going to drop off.

14psi worth of carnage. Well 14psi tapering down to 11-12 at redline when the nut fell off.

https://www.miataturbo.net/attachmen...ine=1430519109

https://www.miataturbo.net/attachmen...ine=1430519109

It was a good excuse to upgrade and I couldn't be happier.

Manifold is known to crack at 14psi.
Little difference in power between 13.5psi and 14psi so why risk it?

:facepalm:

14 psi danger zone

the Manifold is not known to crack at 14 psi. You're using PSI like it's a definitive unit of measure. Like 13.5 PSI won't cause the failure that 14 psi would cause.

It doesn't work that way.

The short answer is: Like any turbo, use it outside its efficiency range long enough and hard enough and it's going to die. I bet it'd last at 14 + psi on a street motor for years and years, but only a season or two on a track car (or even less).

Mine did not fare well with frequent track day events. Even at 11# boost, the restrictive IHI created enough heat to eventually crack the diffuser housing after long sessions of wot. I upgraded to a Garrett and continued to track the car uneventfully at 11#/250rwhp over the past several years. ...knock on wood.

If you look on the mazda-speed.com forum for manifold cracking issues, you'll see that many were running 14psi or over which is why I mentioned it. At that sustained level, the turbo is just generating heat.

Like the <250hp "ceiling" on the stock NA/NB engine, <14psi is considered the "ceiling" on the stock IHI turbo.

You mean like the one I just tuned?

https://scontent-lax.xx.fbcdn.net/hp...07&oe=55E3DB06


Its about as expensive to make an MSM worth having as it is to turbo a regular NB from scratch and with a normal NB from scratch at least you get a garrett.

Our MSMs have 3.6 diff gears.


Dann

Listen Emily, you can take your usable 3.6 and shove it.

We've both been around on the ms.com forum for quite some time. In that time I've never once seen a manifold failure. Regardless of boost pressure. The only manifold related issues is the stud nuts backing themselves off over time. That said there's maybe been a handful of posts about turbo failure.

PSI has nothing to do with manifold cracking.

I have been running my MSM turbo (on 96 8.7:1 compression block) for almost 6 months at 14-15 psi peak boost tapering to 13 at redline. 238hp/232tq. I would not feel comfortable pushing my stock rods or 5-speed past this point. No issues on the street, but I still have to wait for my first turbo'ed track day later in the year to see how it holds up on track. I am running sequential fuel and spark on MS2e with GT500 injectors, so my fueling is much better than any factory ECU setup.

I have been keeping an eye on MAT with different boost levels and saw only minor changes between keeping the peak boost at 13 vs 15. It did become inefficient when pushed as high as 17 and I even saw reduced hp/tq on virtual dyno. There is no HP benefit going above 15.

I have noticed that on extremely long 5th gear pulls at high >5000rpm that MATs will creep up 20-30 degrees more than the usual 30-35 degrees for a normal 2-4th and halfway through 5th pull. The little turbo does heat up on extended 5th gear runs, but I don't think it is much better when peak boost is kept below 13-14psi. I need to do a run with boost limited to 13 psi and see what the MAT impacts are. I also need to do some IR thermometer readings of turbine housing temps after a 13psi peak pull and a 15 psi peak pull.

I was considering only running 13 psi for my track sessions to be safe. But have not found a significant difference in temperature indications between 13 and 15 psi peak boost.

With the research I have done I did not find any manifold cracking issues related to too much boost. At least not unless a fastner or some other component failed first.

I will say that this thing falls on its face after 5500 rpm. Boost comes on nice and early and hold strong through midrange so it is nice for the street. I am concerned that I will be running out of steam in the higher RPM range for most of my driving on CMP. Hopefully I will be able to shift to the next gear and keep RPMs lower in midrange instead of reving the crap out of it and hanging out near redline a lot like I used to do n/a.

Everyone that I have met that uses a MSM for serious track use, not just occasional track days, ended up going to a different turbo that could breathe better and more efficiently in the higher RPM range. I only do one track day a year, two at best so I am hoping the factory MSM will meet my needs for now.

https://www.miataturbo.net/attachmen...1&d=1430828649

Excellent info thankyou :)

Dann

It's weird because I have read this too. I'm currently using a MS2E with stock injectors, and I'm running 14 psi, and haven't had any issues so far. My AFR's at higher boost levels are in the 11.5-12's at that too.

I spoke to the previous who had the car stock, sans the ebay downpipe and asked him if he had any fueling mods, and he said he hadn't.

I know from reading, that there are those who have used the Walbro 255 and it gave them higher fuel pressure which caused them to run richer. Maybe it has to do with the 93 we get here in TX?

I bet they're maxed out at 100% duty cycle though. My 650s run around 60% dutycycle under full boost on the stock IHI.

no

Winner winner, it's hitting 100% or so. I can't put in my RX8 injectors yet, cause i'm having hella weird issues with my MS2E

Martin killed his Thursday. Mine with an upgraded compressor wheel has been beaten to shit on the track for 5 or 6 seasons and has been bulletproof! I've run 15 to 17psi for two years and 13 to 15 before that. Hot side is stock.

The BNR turbo upgrade?

I believe Hyde just has a compressor wheel upgrade.

Think it's a Blouch like mine was. Didn't seem to mind being run at 16psi, held to redline.

Mine had 97k street miles on it and had a few bent fins on the compressor side before the season started, I have a spare going in then this one is getting rebuilt with some goodies