Been chasing this down for a few weeks now and have switched to SD, Custom DP exit front bumper, and open dump o2 housing.

Power is decent, but not where it should be... I know with the .55 A/R BEP I have to run higher boost to see full flow and I'm at 38 PSI steady now.

Click my signature for full build spec, let me know if you see anything that stands out.

What are your timing adjustments on your cams?
My guess is your head setup is restricting the 36 PSI you're trying to throw at it.
480hp at 36psi on an hx40 sounds like restriction to me, you're leaving ALOT on the table. That thing should be pushing damn close to 60Lb/min at that pressure.

I'd get some cams that have at least another .12" of valve lift and 10* of duration @0.50"
Then adjust them appropriately.

Port/polish on the head wouldn't hurt either, but money doesn't grow on trees from what I hear.

What is your elevation? and don't forget that SD will not read airflow correctly like a MAF setup will

97gsxIA said:

What are your timing adjustments on your cams?
My guess is your head setup is restricting the 36 PSI you're trying to throw at it.
480hp at 36psi on an hx40 sounds like restriction to me, you're leaving ALOT on the table. That thing should be pushing damn close to 60Lb/min at that pressure.

I'd get some cams that have at least another .12" of valve lift and 10* of duration @0.50"
Then adjust them appropriately.

Port/polish on the head wouldn't hurt either, but money doesn't grow on trees from what I hear.

Click to expand...

Agreed, sounds like restriction to me also. After some help on the LINK forum I'm leaning towards it being more a tuning issue as I'm on the stock 2g timing map. I was told I need to tailor the map to my setup and could definitely use some help on my DA timing map if you are familiar.

From my understanding I should be adding timing after my load peaks, my load factor peaks at 5K @3.20 and doesn't drop till [email protected]. Do I add timing to those cells starting at 5k where it actually peaks or do I start when it finally drops to 3.15 load @6.5K?

19gsx91 said:

What is your elevation? and don't forget that SD will not read airflow correctly like a MAF setup will

Click to expand...

Elevation is 233' and good to know information on SD.

With that much boost pressure and already seeing small counts of knock in your log, your timing isn't going to do a whole lot for you.
Track your datalog in your timing sheet and add a couple degrees at a time until you see knock. But remember that's your limit, when you see knock, you adjust it back down until its gone.
Right now you're gonna be facing a high boost, low timing tune. Which is what most will prefer anyway. Yes you can optimize your timing table because the 2g map is shit, but its not that terrible and it won't make the kind of difference you are looking for.

With the way you're going I'd use the timing tables to help with spool in the mid range, and get it to where its most efficient up top with no knock.

When I asked what your timing adjustments were, I was referring to your mechanical timing on your cam gears.- that's if you have adjustable cam gears (spoiler alert you should)
If you don't, you now know what you need to do. (bigger cams, adjustable gears)
And PLEASE degree the cams with a degree wheel at zero lash otherwise you're just making random adjustments with no idea if you're within spec at your starting marks.

97gsxIA said:

With that much boost pressure and already seeing small counts of knock in your log, your timing isn't going to do a whole lot for you.
Track your datalog in your timing sheet and add a couple degrees at a time until you see knock. But remember that's your limit, when you see knock, you adjust it back down until its gone.
Right now you're gonna be facing a high boost, low timing tune. Which is what most will prefer anyway. Yes you can optimize your timing table because the 2g map is sh**, but its not that terrible and it won't make the kind of difference you are looking for.

With the way you're going I'd use the timing tables to help with spool in the mid range, and get it to where its most efficient up top with no knock.

When I asked what your timing adjustments were, I was referring to your mechanical timing on your cam gears.- that's if you have adjustable cam gears (spoiler alert you should)
If you don't, you now know what you need to do. (bigger cams, adjustable gears)
And PLEASE degree the cams with a degree wheel at zero lash otherwise you're just making random adjustments with no idea if you're within spec at your starting marks.

Click to expand...

That is GREAT info, so thank you. No I do not have adjustable cam gear and looks like I'll need those and 280's to see full potential of my setup. One thing I noticed was my Load Factor being so high, is that normal? I'll go ahead and add timing from 6.5K up slowly and report back today.

Hows this look for a better timing curve? I'll lower boost a little before testing or would it be better to just use the sliders for this in my currect state?

Adjustable cam gear would help for sure.
Assuming you have more boost pressure than back pressure, you would benefit from increased valve overlap.

I was wondering why you have your IATs locked at 77F?
Since air temp. has a major effect on air density, doesn't the ecu need the actual air temp for accurate calculations?
I don't have much experience with Link but i have alot with hondata (SD).

I used that timing map above that I modified and still peaks at 6K, but stays flat rather then tapering down and the BUTT dyno feels better.

Dusty, IAT's are locked via LINK only because I just installed SD and haven't had a chance to pull the pipe have my IAT bung welded in as this is my Daily. I do believe you're correct about it playing a big role in SD but I don't think its my issue as far as power peaking so early.

Between the hot side and stock intake mani you’re pretty choked up for any power over 7,000 rpms.

donniekak said:

Between the hot side and stock intake mani you’re pretty choked up for any power over 7,000 rpms.

Click to expand...

You know what, that makes sense. Guess after I fix my timing map then this is what I get for my street build. I appreciate that.

I have a stock intake mani (port matched for a larger throttle body) and the same hotside on my HX40, and will agree with Donnie, you're choked up. Mines not as bad because I have oversized valves and a lot of port work on both my head and hotside. There's a definite limit to running stock flange'd turbos and you are about to find that out.
You can max out your setup in a similar way, but you're gonna be dealing with all kinds of tuning headaches and boost creep. Ask me how I know....

Also forget valve overlap, forced induction is not a fan of it. If anything you want less overlap, you got bigger hurdles to worry about though.

Good luck and have fun, love GVR4's.