Sorry for blurry cellphone pics. I am using setting "B" with target of 20psi, no offset and wg set at 12.5psi. The wg setting is probably slightly off after my latest fiddling with the passenger side wg actuator arm but pretty close. I will post my actual boost curve shortly. There is almost no knock sensor activity so I think it is pretty good. I may just add a smidge more boost at 4-4.5k rpm to bring the party just a little earlier but I'm quite happy with it as is...

 

 

Thanks. Now I'm really confused. I'm struggling a bit with this controller. I'm configured similarly but it's still not doing what I want. Yours looks like it's working as I would expect it to.

The one curious thing is in your setting you have the Std.Max.Boost at 10.5 and the Target Boost at 12.5? Per the setup manual the Std.Max.Boost should be equal to wg cracking pressure shouldn't it? I would have expected that to be 12.5 if that's your number. My Std.Max.Boost is set at 14 per my springs but I am interested to see if a few psi less here works better for me. The Target Boost value (12.5) on Page5 just transfers over to the A/B/C tables on Page1 as a starting default. You can see it in your configuration C.

Your boost curve looks good and consistent with your settings. 2 psi above your target boost of 20 per the setting in map B which comes from the additional boost you added from 6k up in the room tables. I've had to increase my Target Boost to 24 psi on Page1 with the same rpm adders at 6k up to get to an actual peak of 20. That's my issue.

What happens when you run map A? Does it also hit 22? It should as 21 x 1.05 is 22.

I also have my drop boost set a bit differently but I'm not hitting the target so I dont think its having an impact. I think I'll copy your setup and see what I get.

I recall you saying you have to completely reset the unit for changes to have an impact. Has that been your experience lately or can you just make adjustments as you go and save them?

We are running out of turbo time here in Ontario. I still hope we can get some of the local cars together to chat more before the year is up. Being able to make some side by side pulls for comparison would be even better. We should pick an event.

 

Setting the wg cracking pressure in the controller is THE most important step in order to reach your boost target. I recall you had a digital device hooked up to tell you exactly what your cracking pressure was. Far more accurate than my eyeball measurement, lol, but it's strange you aren't reaching your boost target.

On map A the boost goes above 23 (as expected I guess) and the safety kicks in. I did this once by mistake but man it was awesome while it lasted until the safety kicked in!

What set me back a long time was the adjustment of the wastegate arm...check both of your wastegate arms to see that the inboard adjusting nuts are tight. My passenger side was loose and until I bought a small right-angle wrench and took the turbo heat shield off I wasn't able to tighten it properly.

The manual is just plain wrong on wastegate setup, at least for our cars. If the wg pressure is set too high you won't reach your boost target. If it is set too low then you will overshoot your target. If you are going to make changes do it by a half psi at a time. You don't have to reset the controller each time for the setting to work (just press both bottom buttons to make sure the setting is saved). Once you are in the neighbourhood of where you want to be with the boost curve then doing one global reset is probably a good idea.

call or text me if you have more questions...

 

Remember I have different springs - they are rated at less than 10psi, and I have a little preload dialed in on them so cracking pressure is around 10.5. I had it set up accurately but it kept on drifting because of the inboard nut loosening over time until I sorted that out.

 

It's good to see your graph correlates with those settings. Confirms it should do what I think.

I'm going to inspect everything today and try some fresh settings in the controller. I set the wg based on my measurements but will play around with this number.

 

Bogg for some reason I dont see any data on your plot showing 24psi....

 

heh heh.

I would love to turn it up further but there's no clear info about the safe limits on pumpgas. Pureporsche overlayed his dynojet "estimated" dyno curve on mine and I think I could add a smidge more around 4-4.5k rpm. The tq peak occurs higher up around 5k rpm vs the vtg tq peak in the low 4k rpm range.

 

Hey Bogg,

Thanks for detailing your Xona experience! I’ve gone through the many related threads to try and get educated on the non-VTG turbos and I think it’s starting to make sense. I may try following in your footsteps with some XR5757s in the near future.

Some questions:
- What blow off valves are you using?
- What hoses are connected to the HKS EVC? I can’t follow the hose diagrams in the HKS manual. Is p19 the relevant diagram?
- Would your setup be able to utilize the Vibrant air manifold that Doobee used?

Thanks!

 

Forge bovs
I don't have manual near but there is vacuum hose from plenum, a hose from each compressor housing teed together, hose out of hks to wastegates, again teed together.
Doobee and I have a similar setup. I believe I could use the Vibrant but not sure what I would gain from it. My engine will be coming down to put proper hoses on so I was thinking about the Vibrant but again I'm not sure I need it....

 

If you have any other specific questions about aftermarket turbos feel free to ask or pm me

 

Hey Bogg,

I plan to use a reputable shop, but I'd like to have general items sorted out rather than assume the shop will get it right.

Do you know which specific Forge BOV’s? At first I thought they might be TiAL Q50MM BOV.

Regarding plumbing, is this essentially what you have?

- Plenum vacuum to EVC (Baseline) & BOV’s & FPR

- EVC (In) to Compressor housing. Was a fitting already available on housing? If not, pressure reference could presumably be from tapping Y-Pipe? Can you pull pressure from BOV?

- EVC (Out) to Wastegates

Sorry for the high level of detail…..

Thanks!

 

Steve, it's a good plan to sort out the details beforehand. I wish there had been a "non-vtg turbos for dummies" thread because there were definitely some things that my shop and I didn't know which in hindsight were responsible for the issues I faced. The biggest one was not knowing that the individual turbo wastegates need to be calibrated upon installation. We didn't know that the wastegate arm bolts needed to be checked and tightened. The shop is really good but they had no experience with aftermarket turbos, and neither did I. I learned as much as I could beforehand but in the end my assumption that you just put the turbos on the car and off you go was wrong, lol.

Calibrating the wastegates is quite easy. I bought the parts off amazon and the compressor from a hardware store and it's really straightforward. Much easier to do before the engine goes back in the car.

I don't recall the bov part number, maybe Sam can chime in? Or reach out to him directly if you like.

My plumbing is how you describe it above. The compressor housing has a port and it just needs a barbed connector (don't know exact size, but it was readily available to my shop) put on and the hose goes to the boost controller. I think Doobee didn't use this port. You could tap somewhere else for the boost reading but I like the way it was done on my car. One thing to consider is that the boost reading in the controller is pre-intercoolers so it may read a little higher than the factory sensor in the y-pipe. I assume that the boost controller reads boost from the compressor housing and vacuum from the line in the plenum but honestly I haven't been able to find the answer if that is actually the case.

One thing that worried me a little was the possibility of a problem if the hose to the wg popped off, broke, or whatever. In that scenario there is the potential for overboosting because the controller would try to signal the wg but it wouldn't get through. Make sure it's a good connection! In my case I've got a McGyvered solution with adapters and couplers which I will get properly sorted out this winter.

 

@Bogg - Reading on the controller should be from the manifold, reading vacuum at idle ... the pre throttle feed is only used for wastegate control ....

 

Thanks for clarifying that, I did wonder how it worked.