Well look what we've got here...

M

MPFab

Supporting Vendor
Briefly drove it. I have the waste gate connected directly to the turbo. This yields 13-14psi. Not terribly exciting at this boost level. It's 10-11psi down from the stock turbo so that is to be expected. I can't just turn the screws to it without dialing the tune in so for the next couple of days, it stays as it is.
The good news is that it is still very responsive. It doesn't spool the turbo when the A/C compressor kicks in like the stock turbo would, but it in no way feels sluggish. It honestly feels similar to how it did with the stock turbo lugging it around or leaving a light.
The bad news....I broke my phone this morning so I have no new pics or videos to show until the phone gets fixed. Should be tomorrow.

I took a pic of the manifold after my drive with my old phone. The color is starting to change. Best I can do currently.
 
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M

MPFab

Supporting Vendor
Preloader said:
One question that burning in my mind is: Can't you run a full MAF tune with a BOV if you dial it in?
Click to expand...

It will never run correctly with a MAF unless you are blowing through the MAF and the BOV is post MAF. Metered air get ejected and the car will go pig rich with a vent to atm BOV.
 
Preloader

Preloader

The M32 Martyr
I have heard that it can be dialed in to compensate at part throttle BOV bleed-off. As far as going rich when you let off the throttle...... Well typically power is not desired when you let off, and I like rice crispies. :D
 
Stew

Stew

Sedans Rule!
Very nice. This is where power levels at 'x' psi will get interesting to compare to the stock turbo. As I understand it you should make similar power at lower boost with the larger turbo, correct? A larger turbo at say 10 psi will flow more air than a smaller turbo will at the same 10 psi, definitely time to put it back on the dyno and see.

Not only that but it should be cooler air at the same psi since the larger turbo isn't having to work as hard to flow a given amount of air. Like the difference between a pancake air compressor and an upright shop size air compressor, the pancake air compressor has to work many times harder to pressurize as much as a larger air compressor which creates more heat.

Mmmm, pancakes.
 
M

MPFab

Supporting Vendor
More impressions...
The car seems to respond much better off boost than before. Most likely it's from removing the "cork" out of its a$$. Leaving a stoplight seems easier. Changes in throttle cause the car to react more quickly. This is an unexpected plus to swapping over.
Boost response is definitely slower, but the car still moves with authority with less boost. One area where the lack of pressure is abundantly clear, is in 6th gear, trying to accelerate up a hill at 60mph. The stock turbo would smack 20psi with authority in that situation and the car would accelerate with ease up the hill. Not so much any more. At that rpm I have maybe 6psi. It feels like I'm towing a boat in that scenario, but if I downshift, all is right with the world again.
In 3rd gear, from a 2K roll on, I see 14psi(full boost currently) around 2.7K. Don't remember what RPM the stocker produced 14psi. Somebody should check that ;)
Once boost is turned up, this thing should be pretty stout for what it is. I'm getting a hint of that now, because I have some boost creep at 6K where boost raises to 20psi and holds. Feels like a rocket comparatively. I knew the potential for this would be strong after receiving the turbo and realizing the waste gate opening was about 14mm. This is WAAAY too small. Not sure why Garrett did this.
I anticipated it being an issue and ported the waste gate opening to roughly 18mm. Apparently it still needs more if I ever intend to run less boost than 20psi...I don't ;).
I'm honestly surprised it's not way worse. I was expecting to possibly have to integrate an external waste gate into the kit, but I believe a little more porting will be all that's needed.
 
rdss

rdss

Junior Member
Guess you got it all buttoned up, sounds like it's going to be strong once you turn up the boost.
 
Blue Moon Sonic

Blue Moon Sonic

New member
I'm pretty sure I've seen the turbo spool as low as 1.7k rpm. I'll hook up my boost gauge again later today to verify when it spools and how much boost I get around the low end.
 
L

Larrymer

New member
Once you optimize the cal for the huge change I bet it will feel completely different. Are you planning to use HPT for all of that? Seems like you should have pretty large VE, cam, spark and boost changes to make. I'm surprised it runs very well at all right now.
 
Blue Moon Sonic

Blue Moon Sonic

New member
It's most likely because of the fact that 14psi on this turbo is probably equal to what our stock turbo was running at around 22psi. It does make sense as to why going to a bigger turbo running less boost works as well as it does. It also seems like the computer is also just trying to dumb down the boost in higher gears just to keep everything within peak power. The ecu is set to do this because when MPfab was driving in 6th gear, it the ecu is telling the car i'm in overdrive and don't need to be running at the full 14psi to achieve gas savings and power needed to keep the car moving forward.
 
L

Larrymer

New member
Doesn't look like it has VVT very well implemented, either. Still a pretty nice tool considering the price. (free) :)
 
M

MPFab

Supporting Vendor
Larrymer said:
Once you optimize the cal for the huge change I bet it will feel completely different. Are you planning to use HPT for all of that? Seems like you should have pretty large VE, cam, spark and boost changes to make. I'm surprised it runs very well at all right now.
Click to expand...

We will continue to use HPT to dial it in. Car should be a lot of fun once that's completed. If this car was speed density it would be struggling, but the beauty of a MAF is its adaptability. There should be more than enough MAF here for the power level I expect too.
 
ScarabEpic22

ScarabEpic22

Member
Larrymer said:
Doesn't look like it has VVT very well implemented, either. Still a pretty nice tool considering the price. (free) :)
Click to expand...

Im betting the only people that can handle VVT in the VVE/VE coeffs are GM and maybe a tuner or two that have a degree in Math...VVE/VE coeffs are straightforward for static cams but VVT introduces many other dimensions.

MPFab said:
We will continue to use HPT to dial it in. Car should be a lot of fun once that's completed. If this car was speed density it would be struggling, but the beauty of a MAF is its adaptability. There should be more than enough MAF here for the power level I expect too.
Click to expand...

Yep and if you run out of hZ for some reason (15k should be plenty though), you can increase the intake diameter. Blade MAF >>> circular MAF w/housing. No comparison and so glad these came with a blade MAF from the factory. My TBSS didnt, but fortunately it's a fairly straightforward conversion. :D
 
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