Always Good info Maestro. You take the fun out of it ha ha. Some of it I assumed and does enter twine so it all makes sense. But it is interesting what literature and retail engineers will tell you. In our aftermarket world if we want to make something custom and will be billet. Once we get into all of the tuning tables on the new car it will be interesting to see where travel protection mode to set up compared to the older generations.

I haven't heard from you in a while or gotten any logs all good? We are doing J's car now with 68 mm it will be fun to go over with you.

Hey Pete, first thing to go or the spark plugs and then the valve seats. We learned that by pushing things as far as they could go. After that you get amount down within milliseconds. Funny enough the turbine was OK but it got pretty hot. Even with a very open bringing system and turbine clip the heads saw a ton of heat. But there's are some other factors that were going on so it's just complicated.

 

I figured I used up all my contact Sam credits for the next decade . Honestly I haven't even been on the forum either much at all. I have been daily driving the car, runs great just like we left it, I haven't touched anything. Been busy with work and working on the house.

Yeah I knew I would take some of the fun out of it, that's why OEMs send marketing guys not engineers to shows to interact with customers lol.

Yes I saw! J sent me some early 68mm logs, looks good already on the base tune. Definitely looking forward to see what you guys can do! We'll be in touch.

 

In my opinion that's a lot more than most people in aftermarket would want to bite off for the return on investment. It would be terrible deal lol. The correct way would be a completely new turbine stage (wheel, housing, vane pack and actuator). For the volume in sales you would have, the 40 guys on here that would buy it, wouldn't even pay for the first week of research (done correctly).

Reasonable options would be using existing deigns and adapting them to the engine. Examples would be GT2 turbines, a different vtg for another application, etc. You can try extrude honing, some guys clip them (though clipping is not great, if you see clipping in an OEM wheel its a band-aid).

If the market was somewhat better well then you can optimize it a little for aftermarket use...you can make a new turbine wheel design but keep the same vane pack, housing, etc. I know everyone is after flow on the turbine side here but look at your logs, flow is not your only problem (you aren't pegged on vanes full open). The new turbine wheel design would need to drive higher efficiency while keeping the same diameter, easier said than done while keeping the wheel in 1 piece LOL.

There is a ton to VTG turbine stage design and we can talk for hours on it. Given its so deep and there is so much IP related to it I can't say much more.

 

In your opinion...are the GT2 turbos the holy grail of VTG turbos?

 

Dunno if I would call them the holy grail, maybe nice to have lol. I looked for them myself before I bought my 63.5mm but the investment was more than I wanted to spend for the return in performance. Buying GT2 cores plus then a compressor upgrade was more than my budget. At the same time if you have that type of budget for turbos, the WGT options start getting real attractive (cost vs power potential).

I would say if the project / problem statement is having the top power producing VTG based car then yeah I would probably do it. If keeping VTGs isn't a constraint start looking at WGT for big power or do compressor wheel upgrades on your standard turbo VTGs. That's my personal take.

 

M3, Jaime got a VBOX! It's on. We need to get data from both cars!

 

Lol yeah I do need to get one. I'll time it this year. I do have plenty of logs we can compare in the meantime though

 

It's the VNT cartridge that's been the issue up until now (if now it is to change). Aftermarket simply doesn't have the resource to make a larger one. There is a reason only Porsche use VNT for petrol cars - it's not easy!

GT2RS is at 700bhp, i expect it will take 750bhp without too much sweat which is over 100bhp up on what we can do reliably with 997 GT2 bases turbos.

Rick

 

They are probably playing with the throttle plate to keep the turbos spooled up on these as well...

 

So what the optimum 991 VTG turbo then..

Es motors 71mm with 991,2 Turbo exhoust hose..?

 

Maybe somebody is already testing it

 

So past a year what is the verdict about 991 GT2RS VTG? Is it good enough to achieve +700hp on a stock metzger with just 93ron?