Just a little update: I've put on a few thousand km with the Xonas and so far so good. I changed the oil last weekend. I must have done at least 30 3rd gear datalog pulls! I was looking back at some of the July datalogs and wish I'd been more meticulous about writing down the settings for each run. I started doing that later on but not so much in the beginning. Also, I didn't realize it in the beginning but when you make a change in the boost controller you need to give it time to make the change by doing multiple runs and power cycling the car.

So far I did a 4th gear 60-130 on pumpgas in 6.7s. There's at least another 0.5s to come off that time because it doesn't hit hard like my 68s or some of my other versions of the tune...but I figured it out. Check out the graph of v5 vs v6:


This is a "virtual" dyno result courtesy of Sam based on my datalogs. V6 differs from V5 only above 6k rpm by adding a tiny bit more timing. I couldn't figure out why the curve was so much "nicer" in v5 until I went back to my notes and realized there were some targeted boost increases in the v5 graph so it's not an apples to apples comparison. Anyway, I'll add a little more down low in v6 to match what v5 did, which puts it around the same whp and wtq as the other thread shows (on 08957's car) at 4k rpm and I think that will really help the times because once it starts pulling it hauls butt!

 

In the 60-130 run my 60-100 time was like 3.8s. If I left the tune alone I bet I could get a faster time by doing a 3-4 shift because the 60-100 in 3rd gear was 2.8s. Even with my birkenstocks I think I could do better than a 1s shift.

 

with 1 shift you should be in the 5s with your setup on pump gas.

 

 

Thanks Sam.

I turned the offset down a little and the overall boost is a little lower and the times are still very good. Consistent 2.8s 60-100 and did a 3.2s 75-110mph in 4th today. That's a simulation of a "road race" by starting off at 74mph in 4th and flooring it. For reference, with the Champion 68s I was able to do 3.7s and the 63s did 4.3s. That's a substantial improvement at each step and the real world value of these turbos is evident. And I still have a few things to try yet.

 

6.5s 60-130 with 3-4 shift, full tank of gas and level ground. major bog after the shift, I think it's because this is the first 4th gear pull after some changes I made. Should definitely have a high 5 or low 6 in it!

 

Have you done more 3/4 fast shifts? What did the bog end up being?

 

Hi,
I just sorted out the camshaft thing and have done tons of 3rd gear logs but just did a 3/4 fast shift and it looks like it still bogs briefly. I suspect it's "user error" somewhere in my setup. The dedicated 3rd gear logs look good as do the 4th gear dedicated logs.

I've been "playing" around with wastegate settings in order to get the boost curve I wanted. That might be a "bad" way to do it...and currently I'm going back to the old way of making the wg set point 2psi below the actual max wg pressure (19.6). That setting had really good driveability but needed either targeted boost increases or adjustments in offset to get the proper boost curve. Setting the wg a psi or so lower (16.5-17) brought the boost in sooner with minimal peaking but it did slightly overshoot the target.

I see that you have the alpha kit...any input appreciated!

 

As I had expected, the bog was indeed a result of "user error"

I changed the wg setting in the HKS unit again today but this time I reset the ecu learning via the Cobb AND reset the HKS controller, meaning it was like starting from scratch. No more bog! I did a couple of hard 3-4 pulls and the logs improve each time - no bog, less tendency toward "richness" and no boost spike at all, compared to the previous bog with lambdas maxing out the rich limit and boost spike. I will work on getting the boost curve I want and with the cool weather I'm looking forward to seeing what the pbox has to say.

 

Did this car ever get actually put on a dyno with street gas? Would be interested to see that.

 

Not yet. Not sure it will happen this season but whenever it does happen I will definitely post it. Once I dial in this version of the map I will ask Sam for a revised version of the virtual dyno estimate just for informational purposes.

 

Just a little update before I put the car away for the winter. Made it to the track day without any cel. It was a cold and wet day and I ended up spinning out - 540degree spin but only 2 wheels off and no damage. Phew! it wasn't from high speed, probably because I lifted off the throttle coming around the exit of a hairpin and that's the wrong thing to do on a rear engine car (I'm a novice!).

Cold weather is great for 3rd gear and up. In second gear what used to be ferocious acceleration is now just ferocious tirespin, lol. In 3rd gear, level ground with half tank of pumpgas I get 2.6s 60-100mph time and that's with target of 21.5psi and no knock sensor activity. Just a few more tweaks to try before putting the car away. Love these turbos and recommend them to those looking for "the next level"...

 

Bogg glad to hear it's running good. To achieve that level of performance on upgraded VTGs we need to be on e85 to bring in the timing. Pretty nice bud

 

I'm dying to unleash the E85 demons down here.....sorting out a CEL to get my logging and tuning back in motion.

 

VTGs on E85 for daily driver is nuts, they hit very very hard which is fun. All out performance I would use the larger wastegate options of course but I do think the upgraded VTGs have their place in the market. Easy bolt on with respectable performance, yes of course not as efficient because we are mis-applying this turbine stage but that's the trade off we make when we choose what hardware to install.