Borg Warner Turbo Matchbot

Anybody else playing around with the Borg Warner Matchbot. It's really neat. Very detailed. None of the cars we have run Borg Warner turbos, but it has been fun to run the numbers with wheels of similar size and spec and kind of see where we are at. 

Here are the results from my Studebaker with the Vortec 4200. It is saying I am probably beginning to get into an undesirable back pressure ratio (I need a larger turbine), and I am likely getting into an inefficient area of the compressor map.

Obviously I should look at the compressor map for my actual turbo, but Precision turbo does not release those, so here's where I am at.

I'll have to hook up a back pressure gauge to the car and see if it is at all accurate. I can say one thing. It really likes the turbo that is on the car right now.

What this is saying is that you need a larger turbine and to operate at a higher pressure ratio.

In reply to chaparral :

Yeah. That would help a lot.

Basically it is telling me to put the old turbo back on the car. I used to have a 7875 on it. I think it was broken which is why it did not work well.

I should dig out the specs of my turbo (also not a Borg Warner) and see where it lies for efficiency

In reply to chaparral :

Of course if you increase pressure ratio, the engine will flow more which will push it further off the map.

In reply to DjGreggieP :

Yeah. It's a fun tool. The videos are really helpful too.

Looks like I could spend a few days playing around with it and validating some of the info. If your backpressure ratio is over 2:1 then a different turbine setup is highly desired (for drag racing at least). Your VE and intercooler efficiency seem high also but I'm not sure how that effects the numbers. 

The Precision compressor wheels are generally *much* better than the BW especially the billet ones. 

In reply to Paul_VR6 :

Yeah. I got my VE from a Dyno graph of a Naturally aspirated engine. I'm mildly confident in it.

Yeah. It's a billet 59mm compressor wheel on the car. It seems to work really well. I'm probably not going to change it. Just thought is was an interesting benchmark.

Precision rates it to 620 flywheel horsepower. We are not there yet.

59mm is what I would think of as a "cute" size for a 4cyl these days. Most of what I see is class spec 62/67/72mm anymore. We can make near four digits on the 72s at 30psi with only 2.8-3L. I would have throught a 75+ with the right hotside would be the ticket for you. I have a customer with a 3.6 we are doing a billet 88mm. 

That's much more advanced then the calculators i screwed around with years ago. Very cool tool. No built-in coverage for low-power small turbo applications, but you can still plot points on the wrong compressor map and more or less transfer them over to the map you actually have. It's a hell of a lot better than nothing and you definitely get more than you pay for. 

In reply to Paul_VR6 :

Yeah. I had a 7875 on the car, and it was just really laggy and didn't pull very hard. It would not make more than 13 pounds of boost, and it smoked a fair amount, so it was probably just broken. I am tempted to try again, but the turbo I am using now is just so happy.

Happy is a good place. If you turn the boost up and you are tapped out, thats it. 

When it was first released, I probably spend about 20 hours setting up hypothetical BP builds. It's what convinced me to go with a billet 20G wheel in the Evo 16G housing for the 323, at least until budget allows for north for $2000. 

I thought I would bump this instead of starting a new thread. I've been spending a lot of time messing with matchbot and trying to validate my turbo and motor build combo, and would very much appreciate some input.

Basically, I have two matchbot model versions, one that follows the turbine curves in matchbot, and one that I used a readily available turbine flow map for this turbine to plot the turbine flow numbers. The one based on the matchbot curves puts me into a bad exhaust to intake pressure ratio (greater than 2:1). The one based on the numbers from the other turbine flow map put me it into a not great, but workable ratio ( 2:1). That's only up at the top end where I expect it to drop off and plan the powerband/gearing accordingly.

Which should I trust? This is for a challenge build, and I have all of $64.95 into the turbo which pairs well on the compressor side. I can spend more on another turbo if necessary, but the budget hit wouldn't be insignificant I think. The turbo is a knockoff "GT"2863.  Here's the turbine map, it came with the .64 A/R housing.

Here's the model matched best I could to it: https://www.borgwarner.com/go/DOQ1Q6
The other numbers have been set as a best guess realistic case scenario. It's a 2.5 VVT duratec with custom intake manifold and throttle for the turbo setup, and IC with water/meth injection. Please feel free to suggest any changes that would more realistically match that setup.

Here's the model matched to the BorgWarner turbine curves. It's a 54mm wheel, so I figured it's at least one whole line step down from the 58mm that's the bottom BorgWarner one.  https://www.borgwarner.com/go/3476MK

Thanks, I love that you can ask questions like this here with a realistic hope of good responses!

24hr bump

nada? any experienced turbo perspective is welcome!