turbo reliability on track
 

reading Savington's post over at m.net. he mentioned a lot of progress in this last year on track turbo reliability. can you guys elaborate on that.

thanks

Read my build thread, I mean "Hustler's List of Regrets". I've gone from a car that wouldn't last 3-laps, then I did a few sessions, then I did a few days, now I'm doing almost nothing aside from replacing wear items with only one mechanical failure in the last year (which now has a fail-safe). I say this with the assumption that I'll fix my brakes tomorrow.

I owe my reliability to Tim Fodor though. Although I don't have the accolades or streetcar lap times to compare to you Commiefornia boys, Savington and I broke a lot of parts and Tim managed to give us something we can't break in terms of "hot-parts". The inconel safetywire helped a lot too.

The two big steps were v-bands and Inconel studs. There was no good solution to the turbo hardware problem before that, and now we have two solid track-tested solutions.

The rest of it is just solid prep work - heat management and quality components.

You can't assert that hot-parts reliability down to v-bands alone. You've forgotten that we have schedule 40-pipe, guessets on every weld, gussets on the WG flange, gussets on the DP welds, Burns double slips, and TiAL V-bands rather than the standard garbage. I did not enjoy my time on the fail-train of swage fit pipe, 2-bolt flanges, gaskets, cracked manifolds, warped manifolds, and broken bolts.

I suppose I take for granted the fact that AF setups are inherently superior to everything else on the market :p

Hustler: nice. I saw it in your thread (48 pages) that your car went 5 seconds under SM record, very nice !! imagine what you can do with some aero work.

That's the beauty though, it looks fairly stock and its quiet. I also drove it to work yesterday. ;)

Its been painstaking to build a car that I can drive 4-hours to Tulsa, race the car for 3-hours, drive to dinner, race for 2-hours, then drive 4-hours home. It beats owning a truck, storing a trailer, and apartment living. Its also enjoyable to have people tell me to watch my mirrors and laugh at the tire trailer.

fastest street Miata in Cali is Sonny's (VegaXT) MSM. he is also 5 seconds under SM record at BW. but he has wing (but no splitter).

not sure about Bob. he was ~5 seconds under SM record at MRLS also. you guys are in a fight for fastest Street driven Miata title in the country I think.

with a wing and splitter (Hoosier don't count, as that can't be street driven, unless u have a ton of $$$), you can probably shave another 2-3 seconds off. and to do that reliably, incredible.

Andrew in his monster Miata just went 10 seconds under at BW13 last week, this was in 100F weather and NT01. what's the most under SM record ? my guess would be a power track like AAA Speedway (where Andrew is 13 under) I think we should have a handicap like Golf. if you are 5 seconds under SM record, you are -5 and so on.

Hallett is fairly tight with 2 of 10-corners that stand alone. I think we'll get into the 1:26's in my car on the next time out. I'm at ECR this week and I expect to be ~10-seconds under the SM record.

John is the hot-shoe around here, I plan to cut more time off with his private instruction. :ky:

10 seconds off SM record in a street driven Miata w/o wing or splitter or Hoosier ? I got to see that. pls do post all the details.

Gordon and I were both on Hankook C71s but I am switching back to NT-01s. Tired of tires that basically stop working after 3 days.

OR if you don't have a govt. job and need to do it without breaking the bank (or free in my case) you can tack weld the flange which relieves the stress on the bolts, and not worry about it. when time comes to remove the turbo i'll drop the dp and unbolt the manifold. 30 sec. with my angle grinder will dismiss the welds. voila, i just saved $3,000. i would loooove to have absurdflow, but that would mean no track days for a year.

ghetto fix for sure, but for sure a fix. i have 15 track days on my car so far. no more broken bolts. oh, btw, we also found out that the bolts that broke were the ones that were exposed directly to the exhaust gasses. on my car it was only the top left bolt that wasn't shrouded (encased) by the manifold at the throat. others had 2-3 bolts (or all) exposed, and they would all break.

what is the sm record there?

Inconel and flat surfaces will achieve the same thing and it doesn't involve a welder.

inconel = $100.00+ and not here when i needed them.
weld = $0.00 and my buddy was here to weld it.

when i replace the turbo, you will be getting a call from me for some hardware

I think I have been between 5 and 8 seconds below spec Miata records on most tracks I have been to. The wing and splitter seem to be good for an additional 2 seconds and I haven’t been back to all the places with them yet.

I sort of got into autocrossing a lot this year after having my 2.0L come apart again and trying to regroup and being afraid of blowing things up again. Been autocrossing and a few track days her and there with a completely stock Protégé bottom end and a stock 99 head much of the year.

I won this year:
Western Washington SCC Slush series - Open Street
Western Washington SCC championship series – Open Street
SCCA North West Regional Series – NS6 (Super Street Mod)
SCCA Northern Pacific Divisional Championship - Super Street Mod
SCCA Packwood National Tour – Super Street Mod
Chuckanut SCC championship series – C2 (Super Street Mod)

Got edged out from winning the Kumho Super Challenge up in BC Canada by not having Hoosier Wets for day 2 and having a strong lead on Day 1

Holy Cow I just realized I’m doing like over 30 autocross events this year in my Street/Track/Autocross car. It is not even really setup for an all out autcross car.

I also did A Time Attack series with it at an outdoor cart track Pacific Grand Prix, didn’t win because I missed one event and lost another event because my transponder fell off and I didnt get a time but the only car that has been around the track faster than me so far is a 300hp Arial Atom running on 275/35/15 Hoosiers.

I also did 6 track days on big tracks Laguna, Portland, Pacific, and Bremerton.

I drove it to work today as well! Been a pretty busy year for my little beast.

Inconell studs have not come loose yet.

Bob

Where can we find out the spec miata records?

The v-bands, bigger brakes, and real radiator are keeping me on track, without issues so far. I wish I was just getting into building a car so i didn't have to loose money with all the different setups i went through.

Isn't that the truth. Do you ever wish you could just go back in time with all the knowledge you have now?
http://artemenko.org/timemachine1.jpg

Are you thinking about switching to a Turbo? I thought your car was pretty darn fast with the supercharger.

I thought you have a few SM record urself ;)
you don't have Inconell studs?

staying Rotrex, has been super reliable for me.. but turbo thing looks like it is now fixed. that's good news for Miata.

1:32.686...anything lower is either ITA and/or on Hoosier R6 or A6.

I think i may be under at the tracks Ive driven. I think you may be mistaking me for Sean? Ive only driven my silver miata around. I swapped to the v-band shortly after sav and hustler proved it to work.

So, how do we find these records?

A google search turned out a lot of times for me.

I know vaguely of few Cali track SM record. I might be off by 1/2 second here.
WSIR - low 1:35 (or high 1:34s)
BW #13, high 2:04s
MRLS - ~1:45
Cali speedway - not too sure on this one, but I believe it is 2:02s.
I think Dean has the record for Infineon. can't remember off top of my head.
I have no idea of Thunderhill. but I am sure if you look at winter's SCCA lap time with mylaps.com, fastest time probably or is very close to lap record.

snowboarder - I did mistaken you for sean.

I am very happy that Sav has taken turbo Miata to a new reliability level. no one will make fun of turbo track Miata any more.

I am very happy that Sav has taken turbo Miata to a new reliability level. no one will make fun of turbo track Miata any more.[/QUOTE]

Ive never had a problem with being made fun of, once on the track. You just have to expect the ignorant GT3 or Z06 owner to scoff at you as they walk by in the paddock before the day starts. And I am crappy driver, I don't run much faster than those times you just posted up, defiantly not 10 sec faster but once you get out there and run I see nothing but surprise from everyone else.

I wish I had video of my last session at NASA's Hallett event. It involved 4 people telling me to get out of the way or let everyone pass me on the grid comprised of Cobras, Vettes, a couple Vipers, and a couple CMC2 cars and I lapped every single car on the track.

What is really bad for me Is I think I’m getting better reliability out of a $250 craigslist motor than I was out of a $10,000 Built Motor by far and it really isn’t that much slower, I still think I’m right at 300 rwhp with it versus 350-360.

Bob

That stuff never gets old. I've shown some pretty serious high powered track and race cars my tail lights on a number of occasions.

Bob

Hustler, stop running with slow Viper/Corvette/Cobra crowds.

this is from last Sunday event during Miata and S2K Challenge. at Buttonwillow #13 during 102F weather.

SM record is 2:05 (in winter). 20 drivers below that. say you are the fastest SM driver, you will be dead last in advanced group. mid pack in high intermediate group.

btw. Sav got FTD, and Trackdayhookey (Rotrex) just 1/10 sec behind him. they both make roughly 350whp.

+1.

is it a combination of everything above ? or is it 2 of 3 ?

Inconel studs/v-bands are needed to solve the turbo falling off problem. You still need the "other stuff" to make sure the rest of the setup doesn't fail. For example, I have a turbo kit with inconel studs and my downpipe started self-destructing and leaving exhaust leaks after fixing the stud problem. I know I'm not the only one with this problem.

V-bands solve the issue of the turbine housing detaching itself from the mani and cutting your sessions short. Then Inconel/monel/nimonic/unicorn-horn bolts safety wired with inconel wire to keep the CHRA from detaching itself from the turbine housing and necessitating a $500+ new CHRA. If you have a standard T25 flange, then inconel turbine:mani studs. Those are the reported solutions for the major issues people have had in the past.

If you want to read more than that, there's a 60-something page thread about stud failures.

Ok this is now a sticky, it is really good info.

Keep it on topic, and add whatever you think is necessary. Both for keeping the turbo attached to the manifold, and keeping the rest of the engine from exploding after you do that.

Are these failures only common after driving at some elite level? I know I have standard hardware, but have not broken anything yet.

I'm wondering if my good laps are as slow as youses guyses cool down laps :bowdown:

Yeah, they typically only show up if you're doing laptimes at or under the Spec Miata record for the track. At some tracks it will show up earlier than that. I had no issues for the first couple of days with my car, and once I started picking up speed it was an epidemic. VagaXT had no issues until he put a set of NT-01s on his MSM, and suddenly he was going 2-3 laps before they'd back out.

FYI, my buddy Matt discovered that bad things happen in my car when your throttle cable melts...and you make that discovery at over 120mph in attempted threshold braking.

I pulled a dumb move and didn't tighten the fitting on the oil return so I had to take it off at the track. I then, had to take it off again immediately because I didn't position the return properly...and did this all in under 1-hour thanks to the V-bands.

Hustler: so how was the MC6 ? how did Matt Andrew do ? I know Savington is antsy to go head to head with him back in cali.

Are you running stock rods at 300 rwhp now and no issues? :eek5:

Yep, 94 Protege stock Bottom end craigslist and a, stock 99 Miata head. The 94 Protege came stock with 9.0:1 pistons.

The big thing is I am not getting lots of oil past the rings and dealing with wierd oily cumbustion mixes with it. it just keeps on going. The last time I ran this setup I broke a valve which made a big mess but I think that was a freak occurance combined with a 7400 rpm rev limit.

Bob

Matt ran stupid fast in his only 2-sessions on that track. MC6? New Master? It was fine but the pedal dropped on the cool-down.

with all this talk about reliability - whens somebody going to organize

"Marauding Miatas 2011"

one-lap-of-america style tour of the best tracks in a region while terrorizing the local v8/subi/evo/etc inhabitants.

some thoughts: select 2 weeks in summer to hit 7 tracks for an easy vacation. or perhaps go crazy and do 5 in one week.

if enough folks participated, could probably ask for own run group. :naughty:

I would be flabbergasted if more than 4 cars on this site could survive 7 track days in 14 days. Mine probably wouldn't.

What happened to the stroker that made you swap it out -- the consumption or something worse?

Started consuming more oil, again.

Oil wetting down spark plugs, again.

Burnt exhaust valve, again.

Wear and score marks on cylinder walls, again.

Damage to rod and main bearings, again.

I saw no degradation in compression or loss of power along the way just increased oil consumption and increasing oil smoke out the tailpipe over time, especially under load. I think the burnt exaust valve stems from the problems caused by Oil in the combustion chamber.

I cannot say with certainty what exactly is causing the issues but running the same turbo setup at the same boost with a stock un-touched internals in the motor has not produced the same wear degradation over time as the built motor. Lost a bit of torque and power due to less displacement is all.

Bob

+1

But they might if driven like a total wus.

I have been a wus this year by doing more autocross and less track. Much less time spent fixing the car that way.

Bob

Wow. Consumption during load... maybe oil carryover, did you ever work up the air/oil separator you were talking about?

Yes Crank case ventilation was and is excellent now and then. I never had any significant Blow By and there was no PCV system that would allow blow by to get back into the intake. Always had good compression and made good power. Oil consumption was under load not vacuum.

I think a combination of stock oil squirters and pistons with gas ports to the oil control rings positioned so they serve as high pressure oil injectors for the rigs is a major contributor to oil consumption. but it still doesn't explain the rapid wear rate.

When it goes back together the squirters will be plugged. FWIW FM is now plugging all the squirters on theire builds. Bill said he was going to do it to mine but he didnt.

Bob

Hmm if you have good (low) crankcase pressures then I would think that high rpm + vac would tend to drive the most oil past the rings. That's when you have the highest delta p across the ring pack & the squirters squirting... or what am I missing?

Now that is interesting. I wonder what the implications are for piston cooling?

To be fair, One Lap of America isn't like doing a full track day. I think you only get a couple laps and they keep your best lap time.

this thread is awesome. thank you guys for shaving so much information!


on a seperate note, do you guys think its better to have a turbo water AND oil cooled? or would you prefer just oil cooled? i think the water cooling is nice but more parts that can physically break...maybe if done properly its not a big deal?

i can't speak from personal experience, but a garrett employee stated following on another forum about garrett ball bearing turbos:

he followed up with follow link (half way down has discussion of importance of water cooling): http://www.turbobygarrett.com/turbob...imization.html

ref: http://nissanroadracing.com/showpost...9&postcount=32

you are the man! thank you for the info!

That is what I thought too. But I could run down a long hill in high rpm vaccume for a long time and not see any oil smoke. Floor it from a steady cruise on flat ground and leave a smoke screen after it came up to full boost. Catch can venting both sides of the valve cover and the lower block to atmosphere wouldn’t collect hardly anything unless I was doing hard cornering on a track and then I think slosh was a big player. I get as much oil in my catch can now but nothing showing up on the plugs like it was.

I suspect others running the piss out of there cars on the track with aftermarket pistons are also having oil control issues. Just haven’t identified it. I suspect the low height Stroker pistons makes it worse.

Bob

Heck of a situation. Good troubleshooting btw. Could this be ring flutter?

I’m theorizing that it doesn’t make much difference. The only pistons I have seen that were made to take full advantage of those squinters are the pistons Mazda put in the GTR engine. They had an internal oil galley channeling the oil through them and iron ring lands. The stock pistons also don’t have gas vent holes going from the oil control ring area to the inside of the skirt area that is being blasted with oil spray like I think all the aftermarket pistons do.

Bob

another tidbit on the water cooling which i didn't see mentioned on the web page sited earlier:

I haven't seen it if I am, and I just ran 5-hours over two days and never lost any measurable oil while checking plugs the first day for a spark problem. I have no aero however, so I don't see the lateral g-loading that you do.

Rob S (Garrett guy in those links) knows what's up.

Summary: if you want your bb turbo to fail, do not attach water lines to it.

This happened to a friend of mine with a turbo setup on his NASA TTC-prepped turbo Miata at ~200rwhp. Fortunately, he noticed the problem before the cable completely froze up and we fixed in in the paddock. Be aware of this failure mode if you're running a turbo on the track.

And to add another data point - he's been using inconel studs on his car for the past several events, and that seems to have eliminated his problems with manifold bolts stretching and resultant warping of the mating surfaces.