great421

iTrader: (1)

All -

Took the bird out to the 1/4 mile track with a group of guys on Sunday and, while doing a burnout, heard a "Bang!" - with that, the turbo was locked.

Not a good day.

So, I've been on the phone all day trying to get a replacement unit ASAP. Now, the STS guys tell me I have a Garrett 60-1 with a P-Trim exhaust wheel (whatever that means), and at 11 lbs of boost I probably "Overspun" the turbo.

Now, while I understand the concept of exceeding a turbo's abilities, I also know that this is the turbo which came in their kit. Therefore, how could my little old 355, which almost never exceeds 5,500 RPMs, "overspin" a properly sized turbo?

So, to ask the FI Forum guys, can an engine overspin a properly sized turbo, or where the folks from STS just guessing?

PS: They'll happily sell me a new 67 mm turbo (with ball bearings) for the low low price of $1600, but I thought that price was a touch expensive.

mike13

iTrader: (27)

Yep it computes, I had a T67 that I broke the turbine shaft. You don't need to by a turbo from STS, many other options. I would look into a turbonetics tc76, it's a much larger turbo but with the right a/r housing can spool like a t60 or t67.

kbracing96

iTrader: (25)

Sounds kinda fishy, it shouldn't have over spun it cuz I doubt you were even at 10psi and 5500 during the burn out. A Master power T70 with a .68 a/r would be pretty good for your setup. They only run about $625,

mike13

iTrader: (27)

Forgot about the master power T70, the problem with the T60 they use on the sts is that most people complain of the power falling of before 5k.

great421

iTrader: (1)

M13 / All -

Forgive my ignorance, because I may be working from a false assumption, but if my 60 mm turbo was "too small" to push 11 lbs of boost, but the correct size for my vehicle, then wouldn't a 76 mm unit (which is 27% larger) also be 27% slower at building boost? Or is spool time / spool RPM more a function of the A/R ratio?

(BTW - Thanks for the assistance; I'm just trying to get my mind around all the variables associated with picking the proper turbo.)

mike13

iTrader: (27)

spool is more a function of a/r when your talking the same size frame of turbo. The TC76 is a 76mm compressor wheel in a smaller housing, it's a popular turbo for the rearmounts, if you talk to Forced Inductions they can size the a/r for the perfect match.

There's other turbos that will work well, I just know from first hand experience and research that the TC76 is a good one to consider.

Dragframe

iTrader: (14)

What in the world do you mean forget about the master power t70?

mike13

iTrader: (27)

I said I forgot not forget.

one fast zo6

iTrader: (490)

cheap master power T70 for the win!

EATON22

I doubt that you overspun your Turbo ; not even sure what that means. It might have failed but over spinning is a new term for me.....

EATON22

I would suggest that you will continue to have issues with the STS system. Get someone to build you a single turbo kit and put it under the hood behind one of your head lights and much closer to the exhaust signal. I have seen guys be able to spool small housing 88 and drive them on the street with a/c .....

longrange4u

iTrader: (2)

Call Jose and crew at ForcedInductions (Sponsor)... they will square ya. On your build (assuming you have the fuel and block to handle it) I would say GTS76 or at least at TC72 or so..

Bobsmyuncle

iTrader: (32)

ever hear of over spinning a motor??????

when **** spins too fast, **** breaks. kinda an easy concept. lol

NicD

iTrader: (7)

Only STS would sell you a 60-1 turbo for a 350ci motor. That thing is ridiculously small and anything but properly sized and it probably did eat itself in the process of trying to make 11 psi on your motor. Then again do you know for sure it was a genuine Garret turbo? I have seen so many chinese POS turbos in the STS kits. What about oil pressure/oiling system going to the turbo?

Do something like a MasterPower 70 or 76 q-trim for that size motor but it will definitely spool slower than what you are used to with that 60-1.

abbaskhan

heres a comprsosor map for a average 60-1 looks like you were close to the limit of a 60-1

http://www.turbocharged.com/catalog/compmaps/fig9.html

also consider who spec'd you the turbo and what it was designed to do! if sts did it and they knew your target range for psi and HP they spec'd it wrong....

back to if you over spun it.... ALL THINGS BEING GOOD INSIDE THE TURBO that leaves the waste gate and maybe boost spikes (comprssor surge or one of many other reasons .... these would show signs while boosting) AND if you didnt experience any thing outta the normal.. maybe the sts pump went loco (has happened on occasion) id look at the fact the turbo was at the limit and specd wrong in the first place

bottom line rebuild the turbo sell it (cost vary from 200 to 400 bucks if they arent try to take your cash and run ...imho you can do it yourself) meanwhile buy a decent MPt70 or t76 for around 700 bucks and run it with a t4 .84 or .70 housing and and when you have rebuilt the turbo sell it!

if you can buy the mpt76 (and run a quick spool valve if cash permits)
(id go t76 t4 .84 or .70 if your limited in rpm)

heres link to a thread this guy dyno'd the mp t70 vs mp t76

http://www.theturboforums.com/smf/in...prev_next=prev

great421

iTrader: (1)

OK, so the 60-1 is too small - got it.

I'm taking it off tomorrow after I finish teaching (college professor here), so I'll be able to confirm that it indeed is an actual Garrett turbo. I cannot recall seeing, or NOT seeing for that matter, "Garrett" on the housing, but I'll check and see when I take it off.

My oil pressure was good, too good actually - 40 psi @ idle warm, and 65-70 psi at WOT (warm) - I had an oil restrictor in it for the last year and a half due to oil blowing by the seals.

Forgive my ignorance, who makes a "MasterPower" turbo?

Yep - it's the "standard" turbo for the LT1 cars. Having said that, my understanding is that their kit is for 5 to 7 psi, so I exceeded their design specification.

Got it - a second vote for the 60-1 being too small for my usage.

Again, what is a "MPt70" and who makes it? Is it domestic brand name, or from China? (Maybe I should just Google it. )

mike13

iTrader: (27)

Master Power is the maker, I think they're in Brazil, they have reputation of being a budget turbo. Better than a Chinese turbo but not a Garrett or Turbonetics, etc.

abbaskhan

master power T70 turbo t4 frame (dont buy the ebay crap no matter wat) contact modular turbo on here hes a dealer and seems like a decent guy and willing to help

heres the modular turbo guys info...... found it on the forum in here

Call 252-562-3899

hawaiifiveoh

Master power has proven time and again to be as good or better reliability wise as any other aftermarket brand, and does work at the same time. Another vote for MP budget turbo here.

Sideways240sx

iTrader: (22)

Ok... Just want to make sure your on the right page, since no one else said it.

Its not that the 60mm was to small to push 11lbs of boost. Boost is a restrictions. 11 psi on a 88mm turbo is a ton more air then 11psi on a 60mm turbo. that being said, the bigger the motor, as you go higher in boost you run past the turbo's effecancy. Doing this will make everything get hotter, and cause it to fail sooner, possibly.

rear mounts spool slower, but a properly sized turbo with the correct ar, you should be able to get quick spooling 76 mm turbo.

Lots of people run the turbonetics tc76 and can spool that turbo really early, and i bet you can make the same hp you do on the 60mm @ 11 psi, by 7 psi on the tc76.

Good luck, Chris