Hey guys,

hope all is well around here, have not been coming on here for awhile, but might aswell give you my story.

was running my car 997.1 6speed on track and all of sudden going from 3rd to forth and i see a cloud of white smoke coming from the rear end of the car. took the car on a flat bed to a garage and opened up everything. turns out my passenger side turbo over spun which resulted in breaking the compressor wheel as you can see the below pics, and driver side turbo is just leaking.

So now my main question is. As i have been searching regarding VTG upgrades and results on cars in terms of quarter mile times or even Vbox number, And i just cant seem to find any solid info regarding 65mm or 68mm turbos in terms of power they made or Vbox numbers. So please guys any help regarding this information?

And who is the best VTG turbo builder out there? and is it worth to go VTG setup again or just Alpha turbos. Again i dont want to spend an arm and a leg so what is your best recommendations?

My car is tuned by Emre from Esmotor and will stay with emre. Car has tune and exhaust running our 98oct pump fuel with Meth. My car was making 575whp and resulting 6.7 to 6.9 in 60-130 Vbox numbers.

 

There is some information out on the forum on what upgraded vtg options will make in terms on power. I would say you can expect 700whp depending on fuel. That is very close to the top end on average. You mention your tuner is ES Motor, I believe they offer an option. In the U.S. based on the data I have collected I would use 65mm from Sam@ByDesign or 63.5mm from Protomotive.

Regarding your picture you are looking at the turbine wheel not compressor. If you notice 1 turbine blade is damaged differently than the rest. It looks like you had a 2nd mode high cycle fatigue failure. Hard to tell you with 100% certainty because I cant physically look at the part. However if it was high cycle fatigue then it was because of overspeed. You need to ask yourself why did it over speed and address that.

On the upgraded turbos most turbo builders will "clip" the turbine wheel saying it offers more flow. They don't understand in a vtg design the wheel isn't necessarily the flow constraint. However what they don't know is by them clipping you have now stiffened the turbine blades. They will ping at a higher natural frequency. So what does this mean? Lol. You raised your speed limit on the turbine side.

There is some turbo info in my build thread otherwise I can also help you with any questions through messaging as well


Good luck.

 

To the OP, listen to M3 Maestro as he works with turbos for a living and REALLY knows what he is talking about. Him and I have been conversing for awhile regarding his build and am impressed by his knowledge.

 

Sorry to hear that brother, I bet it was those DV's .... Go Alpha so we can race like old times ....

To upgrade the VTG vendors will ask for a good core, otherwise they will cost close to what TiAL's alphas do, few changes and u got 700 to the wheels on 98, VTG's will get there but on racefuel ....

 

Those turbos look fine, just put them back on and add some injector cleaner just to be safe and you will be good to go.

 

thank you very much for your information that really helped alot, yes im at the moment trying to figure out if my cores are ok or not. And yes most probably i will go with emre's option and whatever he offers and reccomends me to do. he knows exactly what my driving style is like so hopefully we will come up with a setup that suits me best, and maybe hopefully a vtg record if we can do it and if it is possible. and your help is highly appreciated thanks alot.

 

yes i been watching his build thread and im glad we have people like him with such great knowledge to help us out here.

 

whats up doc how u been man? yeah im thinking now here and there on what to go with they either gona be 3071 or emres vtg secret new recipe . also i dont want to go with boost controller hassle and all yet. maybe that will be a later root but once i go build engine. i dont think my car is worth upgrading to alpha turbos without am engine build.

hows your car now? where have u been i dont see you around?

 

they dont look at the compressor wheel on one of the turbos.

 

My friend has a very good set of Protomotive VTG's 63.5mm for sale. If any interest let me know.

 

In regards to having a good core, that is an excellent point. This will not be a good core for an upgrade most likely. When we lose such a large section of blade the amount of imbalance is pretty high. This will drive high shaft motion and squeeze the oil film out in the bearings (single radial bearing in this design, "semi-float" design, cheaper and less noise, common in automotive). Once you tear this turbo down, you should see the radial bearing is damaged allowing for high clearance. The additional clearance will let the wheels contact the housings. On the compressor side its not too bad because you would be boring and re-profiling that side anyways for the bigger compressor wheel. On the turbine side is where the issue would be. These turbine stages have the an insert that connects the volute to the discharge. That insert is profiled to the turbine wheel and completes the housing. I would expect it to be damaged. That insert in tac welded onto the turbine housing and holds the vane pack in place. In addition you will need a new turbine wheel/shaft assembly.

So essentially, the parts you need for re-use (bearing housing(might be damaged too), turbine housing, turbine shaft/wheel assembly) in the upgrade have a likelihood of being damaged.

I think ES Motor will point you in the right direction, their achievements speak for themselves. If you have more turbocharger specific questions I'm always happy to help.

 

Another great option to look at is srm efr7163. Sean and I were talking last week to about being able to make a efr6758 which would have better response and be in the 900whp capable range on e85 I race gas.
they are in stock housings and bolt right on.

 

Nice chatting with you Naj. Here to help if I can with 65 HTZ's ready to go.

 

If it were me after all the experience i have been through over the years i would be not going for a vtg upgrade as at some point you will want more.

Personally I would speak with SRM and go for their efr bolt on kit as they spool great and can achieve at low boost what vtg achieve with hi boost. Less boost equals less stress and less heat and much more power down the line

Either way I hope you sort your car out.

 

I think Naj is going for a VTG record With Emre. After that there are some pretty great options with a boost controller and conventional turbo's.