Ok, Here's the track numbers from a few weeks ago with the STS kit T60-1 turbo with .68 a/r exhaust housing, 11.5 lbs of boost with Meth. DA was about 8400' and was pretty warm. I did have some exhaust leaks that warn't helping (1/4 of the waste gate gasket was blown out and a little leaking at the catback flange) It was very difficult to build boost on the line.

60'..........2.36
1/8 ET.....9.571
1/8 MPH..77.47
1/4 ET.....14.593
1/4 MPH...99.09

Here is the log from that run. Keep in mind that up here, 4800' my static air pressure is about 86 kPa.





And here is my track times from yesterday with the KBracing Custom front mount turbo (read more here) . DA was about 8200'. Same T60-1 with .68 a/r exhaust housing.

60'..........1.95
1/8 ET.....8.44
1/8 MPH...82.13
1/4 ET.....13.21
1/4 MPH...103.5

Here is the log. You can see I launched with more boost and was in 1st gear a lot less time. That's where I gained most of my time I think. It was really easy to build boost on the line. I had to be careful, a couple times I started brake boosting too soon and left with about 10psi and it woulds spin and hop off the line, lol which didn't help the 60' times

 

So wait, what was your setup when you pulled that 12.79?

 

That was the STS in Phoenix at night in March. Thunder550 was there. Nice and cool and only 1200' elevation. Altitude KILLS power! Another 2 psi of boost or so, on the front mount and I could be at those numbers up here.

 

Ah ok I didn't realize that. Those numbers are extremely impressive then.

 

they have to be more to it cause look at wildracing with his truck that is a sts and a stock motor and trans running 11.41 so they can't be that much different.

 

wilderacing had a LQ4-6.0L
kbracing has a 4.8L




great numbers man. i never understood how the sts could have the same spool time and make the same power as a front mount, guess they( different comments on web forums) were wrong.

 

It's nice to see some numbers to back up my butt dyno experience. I know you're real big into drivabilty on the street, because that's where we drive , but I think front mounts have better drivability. More low end, quicker spool etc. makes for a better street truck. STS says that front mounts are more suited for max effort track only setups, and to me it seems to be quite the opposite. It seems the STS's shine on the track where you can have a half hour to spool the turbo, but to me, on the street, they're not nearly as fast and fun to drive.

I wish it were the same temperature between there and AZ though. Theoretically 11psi is 11psi no matter what the altitude is. But up there your turbo is having to spin a lot faster to achieve 11psi, so your in a different island on the map. Your IAT's seem to be the same though, but that's probably due to the meth. It appears turbos ARE affected by elevation, just not as much as other forms of induction.

Nice work and numbers!

 

I think the altitude and small exhaust leaks is what played the most into it. In the thin air, it didn't spool quickly, but look at my best, that 12.79 was at 1200' with cool air. I could brake stall boost down there, and I couldn't up here. That's a lot of the difference. Wilde's times where in similar conditions with cool temps and sea-level. My truck runs WAY different from sea-level to 5000'. The biggest difference is in the NA pre-boost area, and the front mount really minimizes that time, thats where it really performs. I was quite surprised that it picked up what it did, but at the track, it's almost all in the short time.

You guys who live at or around sea-level really don't understand how much altitude affects power.

 

And I'm REALLY glad it's not the same temperature here as it its there!

I agree, the front mount is a lot more fun to drive, but it's not helping my fuel mileage

Actually, 11psi at sea-level is not 11psi at 5000' at least in ACTUAL air pressure (kPa). To get the same kPa, I would have to run 2psi more to be at the same air pressure.

 

I think the best comparison will be when I get back down to Phoenix though. Don't think I'll pickup over a second over the STS there