ideally whats the best boost targets for custom tune from full boost to redline?

[Wenis Prinkle]

when i get dyno tuned in a couple days i was wanting to know whats the ideal boost settings with proper tuning of course to squeeze the most potential from the wussy ko4. now un tuned i hit around 20-22 and then it tapers to 15-16 at redline. with a pro tuner and proper tuning equipment what should i set the boost level to hit at wot? and then whats the highest you recommend i set it to hold to redline assuming all it good with every other aspect of the tune? when is this turbo most efficient and when does it just start blowing hot air? is it more beneficial to run a pound or two less and then add more timing to make up for the power loss or the other way around? please advise, thanks!

[cld12pk2go]

Here are my current boost targets.

[subparpunk03]

Yeah its in german but you can still get the info you need out of it.

Long story short... I would not push it past 20 psi.

I know you are trying to push the stock turbo to its limit... and I know its been said before, but Methanol injection is a very good idea. If you inject water/meth before the turbo compressor you can alter the compressor map a little bit and you can get a little more CFM out of it at the same PSI... but you risk damaging the compressor wheel if you inject too much.

[Wenis Prinkle]

OK thanks you guys!! so if i can get the afrs where i need them with zero knock at WOT it should be safe running20-21psi peak and then fall to 19psi all the way to redline???? or would i benefit more by tapering the boost even lower by redline?

[bast525]

19 psi to redline is way too high, way too long IMO. If I had full intake/FMIC/turboback exhaust, I would aim for peak 19-20 around 4000 rpm, and taper it down to 15-16 by 6000 rpm, then have it drop off drastically after 6k, like stock. You dont want to spin the shit out of the stock turbo, you are NOT going to increase power much past that RPM. The compressor maps show that up at that RPM, anything more than 15 or so after 6000 rpm the efficiency is shit and gets worse rapidly.

[acidbbg]

Originally Posted by Wenis Prinkle when i get dyno tuned in a couple days i was wanting to know whats the ideal boost settings with proper tuning of course to squeeze the most potential from the wussy ko4. now un tuned i hit around 20-22 and then it tapers to 15-16 at redline. with a pro tuner and proper tuning equipment what should i set the boost level to hit at wot? and then whats the highest you recommend i set it to hold to redline assuming all it good with every other aspect of the tune? when is this turbo most efficient and when does it just start blowing hot air? is it more beneficial to run a pound or two less and then add more timing to make up for the power loss or the other way around? please advise, thanks!

That really depends on your mods.

If you have the upgraded IC...and running 93octane...You should be able to do 20psi spike but tapering to 15psi by redline.

At that boost you need to let the car cool between runs.

[cld12pk2go]

.

Originally Posted by bast525 19 psi to redline is way too high, way too long IMO. If I had full intake/FMIC/turboback exhaust, I would aim for peak 19-20 around 4000 rpm, and taper it down to 15-16 by 6000 rpm, then have it drop off drastically after 6k, like stock. You dont want to spin the shit out of the stock turbo, you are NOT going to increase power much past that RPM. The compressor maps show that up at that RPM, anything more than 15 or so after 6000 rpm the efficiency is shit and gets worse rapidly.

Agreed. That is why I am aiming for 16 PSI at 6k RPMs and tapering to 10 PSI at 7k.

[itzl0l]

^^^^ u do realize the boost targets tables isnt used for WOT right....

[cld12pk2go]

Originally Posted by itzl0l ^^^^ u do realize the boost targets tables isnt used for WOT right....

It seems to be used sometimes. The exact nature of the logic the ECU uses to incorporate the boost targets table isn't all that well understood last that I checked.

You are correct that the TRL tables are mostly used at WOT, but to answer the original question of ballpark boost curves/capabilities I posed the boost target table instead of my TRL tables...

[bast525]

I think he showed boost targets more to easily answer the OP's question, but yeah, you will have to spend more time with the Throttle Requested Load tables to get the boost curve you want. I even adjusted Wastegate Duty Cycle somewhat. Lots of ways to adjust boost with ATR. You have Boost Comp as well. Gets pretty rediculous

[jahman]

Actually if your TRL tables are in line, then boost targets are followed pretty closely at wot. It seems if you request something ridiculously high, then itll ignore boost targets completely.

I've actually watched my DH give me the exact boost set in boost targets tables when I have my TRL tables and boost target tables set to "agree" well with one another.

[Wenis Prinkle]

ok so then 20-21 at peak and taper down to 16 at redline it is then!! thanks for all your info guys, your tha best!!!!

[cld12pk2go]

Originally Posted by Wenis Prinkle ok so then 20-21 at peak and taper down to 16 at redline it is then!! thanks for all your info guys, your tha best!!!!

I would avoid 20-21 at ~3000 RPMs if you have a desire to keep your rods from exiting your block in an unfortunate manner.

Personally, I would try to keep it to ~19 or so and try to limit boost in the 2500-3000 RPM range to minimize the potential for rod failure.

And 16 PSI at redline = wayyyyy off the turbo's efficiency island.

Of course the choice is yours.

[Wenis Prinkle]

if 22 peak around 3600 rpms and 17-18 psi at redline is bad then why do the OTS maps do this?

[bast525]

Originally Posted by Wenis Prinkle if 22 peak around 3600 rpms and 17-18 psi at redline is bad then why do the OTS maps do this?

Because that's what a lot of less informed people demanded. Cobb's first maps were far more conservative, which is typical for them. But a lot of the Mazdaspeed community bitched about it. Everyone wanted big torque down low and big power above 6000 rpm. Now we all know a little better. Big torque down low puts too much stress on the rods, aim for peak torque around 3500-4000 rpm. Holding power to redline is not going to happen with the stock turbo and stock cams, period. Mazda wanted boost to fall off quick after 6000 rpm for a reason.... to keep from stressing the turbo. 16 psi at 6000 rpm is borderline, with full bolt ons it would probably be ok, but let the boost fall off quickly after that.

[cld12pk2go]

Originally Posted by Wenis Prinkle if 22 peak around 3600 rpms and 17-18 psi at redline is bad then why do the OTS maps do this?

It could be related to the fact that alot of Cobbs test mules were tuned at ~5000 ft elevation and required higher load settings to acheive the boost targets and when people at sea level start using those tables they are hitting higher boost.

[Wenis Prinkle]

wow so avoid boost until 4000 rpms and have it fall off at 6000rpms huh.... thats only 2000 rpms of power, thats worse than having VTEC LOL!!. ill shoot for 19-20 round 3300-3500 and have it taper to 16 by redline as long as everything else looks ok im sure this is fine. i will post results tomorrow.

[fjames]

People keep acting like you can just plug a value into ATR and it will magically happen in real life. I think everyone would have better luck looking at boost control in ATR as a guide, because that's all it really is.

Someone said the ots maps ran high boost at high rpm - they don't according to the maps, they all fall off after 5.5K. Doesn't mean the car does though.

It seems pretty simple to me, so maybe I'm wrong, but the way Cobb sets up the maps, and the way most people tune with ATR, WG is your only mechanism for controlling boost. It works fine for increasing boost to meet a target that's higher than current value, but horribly at reducing boost to reach a lower target.

Boost (whether load targeted or whatever) in this car is basically, spike->taper->maybe get a little control of it before you shift.

Addressing spike would seem to be the best approach then. I've seen a few dynos of the stock turbo that don't have the hump at tq peak. Don't know if it's the way they drove it on the dyno, or tuned it, and if tuning don't know if they lowered the bump or raised everything else. But I've seen tq curves without the spike so it can be done.

Funny though, I've seen two opposite approaches to it. One says increase targets early, so you'd have big numbers starting at say 2.5K. Theory is (I think) that since you can't really get max torque that early, the system would be maxed already trying to meet that target so it wouldn't spike as rpms climbed. The opposite is also done though - lower targets early and delay the big numbers until 4K say.

Stare at the below long enough and it's kind of interesting. First is my current 4th gear load targets, then is the same from custom etune I got.

0.70	0.83	0.97	1.15	1.25	1.41	1.62	1.72	1.78	1.76	1.74	1.70	1.66	1.56	1.51

0.70	0.83	0.97	1.15	1.47	1.78	1.80	1.77	1.74	1.74	1.75	1.73	1.65	1.58	1.58

Don't ask me how it drove, I don't know. Well, I do, it drove like a stock tune because that's in effect what it was - they didn't know at the time (or forgot or something) that the ecu targeted the lower value between gear and TRL so they left TRL with stock values. I got my money back so no worries, but I was pretty pissed at the time. Now with ATR, I can see what was going on, but at the time I thought they were lying to me.

Anyhow, it shows an interesting approach to tuning load. Cobb seems to be going to opposite way lately - their higher tunes have the highest values a step up in rpm than they used to in general. But there's so little consistency in their different maps it's hard to really say anything.

Back to my basic point, that WG is useless for decreasing boost on these cars ... Boost Limit Throttle Control seems like the best way discovered so far to really effect boost post spike. I run mine about 1 whole number higher than whatever load target is at that rpm. So a 1.8 load gets a 1.9 BLTC. Seems to work okay, but it still spikes.

I have a LWG (low waste gate) map or two from the old days, and the values are down in the teens mostly IIRC. Something to think about - what is the relationship (or is there one) between the values in the WG table, and what we log? There doesn't seem to be any, unless maybe you double the values (so a 40 value = 80 for real.) I drove this map for some time because I had such bad part throttle cut on the 103 maps (now with ATR I know why.)

Here's that WG table if someone wants it for guidance - from a S2+ v102 msf map.

0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00
0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00
0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00
0.00	0.00	0.00	0.00	10.75	6.43	5.57	5.32	6.10	6.20	7.38	4.75	2.88	3.88	0.00
50.00	50.00	50.00	41.00	21.50	12.85	11.15	10.65	12.20	10.59	8.98	7.36	5.75	7.75	0.00
50.00	50.00	50.00	41.00	28.00	19.28	16.72	15.97	14.64	13.02	11.40	9.78	8.16	11.63	0.00
50.00	50.00	50.00	41.00	28.00	27.70	24.30	23.30	17.08	15.45	13.82	12.20	10.57	15.50	0.00
50.00	50.00	50.00	41.00	28.00	26.70	29.30	27.30	19.52	17.89	16.25	12.61	12.98	15.50	0.00
50.00	50.00	50.00	41.00	28.00	26.70	29.30	27.30	23.81	20.32	18.67	15.03	15.39	15.50	0.00
50.00	50.00	50.00	41.00	28.00	26.70	29.30	27.30	25.02	22.75	21.10	17.45	17.80	15.50	0.00
50.00	50.00	50.00	41.00	28.00	26.70	29.30	27.30	24.69	22.08	20.61	17.13	17.80	15.50	0.00
50.00	50.00	50.00	41.00	28.00	26.70	29.30	27.30	25.01	22.72	21.17	17.62	17.80	15.50	0.00
50.00	50.00	50.00	41.00	28.00	26.70	29.30	27.30	25.33	23.36	21.73	18.10	17.80	15.50	0.00
50.00	50.00	50.00	41.00	28.00	28.70	29.30	27.30	25.65	24.01	22.29	18.58	17.80	15.50	0.00
50.00	50.00	50.00	41.00	28.00	28.70	29.30	27.30	25.97	24.65	22.86	19.06	17.80	15.50	0.00
50.00	50.00	50.00	41.00	28.00	28.70	29.30	27.30	25.97	24.65	22.86	19.06	17.80	15.50	0.00
50.00	50.00	50.00	41.00	28.00	28.70	29.30	27.30	25.97	24.65	22.86	19.06	17.80	15.50	0.00

This map drove different, you could feel the lower WG, but it's globally lower, no nit-picking around, so maybe that's what it takes to get any real change from screwing with WG values.

I'm pretty sure I'm tired of writing now, so I'm not even going to fucking read this thing, just post it and get it over with.

[cld12pk2go]

Originally Posted by fjames People keep acting like you can just plug a value into ATR and it will magically happen in real life. I think everyone would have better luck looking at boost control in ATR as a guide, because that's all it really is.

Good discussion.

Our ECU is certainly not my AEM EMS on my TurboMustang where I just tune the PI loop for boost pressure and it goes right to my target and does not deviate 0.1 PSI. This ECU does a lot of convoluted shit with respect to aiming for torque from various tables.


I started tweaking the WG DC in my last map and it appears to have helped somewhat with spikes around 3k. However, I also applied the throttle smoothing fixes on the same map so it could be related to that. I also wait until 3500RPM in all my TRL tables to go to make max load. Here is my latest TRL:



However, my actual WG DC is quite a bit different on my logs from my tables. Specifically, the tables were considerably higher around 2500-3500 RPMs, which would be expected to result in spikes.

Here is the WG DC of my current tune with some small changes made to the 2500-3500 RPM range:

0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0	0.0
0.0	0.0	0.0	0.0	0.0	20.0	20.0	20.0	20.0	20.0	20.0	18.0	18.0	5.0	0.0
25.0	25.0	25.0	25.0	25.0	26.0	26.0	28.3	31.4	25.0	25.0	22.0	22.0	9.5	0.0
40.0	40.0	40.0	40.0	40.0	30.0	27.0	28.3	31.4	31.8	31.0	24.0	24.0	14.0	0.0
50.0	50.0	50.0	50.0	50.0	31.0	28.0	28.3	31.4	31.8	36.5	26.0	26.0	18.5	0.0
50.0	50.0	50.0	50.0	50.0	31.0	28.0	28.3	31.4	31.8	36.5	28.0	28.0	23.0	0.0
50.0	50.0	50.0	50.0	50.0	31.0	28.0	28.3	31.4	31.8	36.5	30.0	30.0	25.0	0.0
50.0	50.0	50.0	50.0	50.0	31.0	28.0	28.3	31.4	31.8	36.5	41.0	41.0	28.8	0.0
50.0	50.0	50.0	50.0	50.0	31.0	28.0	28.3	31.4	31.8	36.5	41.0	41.0	28.8	0.0
50.0	50.0	50.0	50.0	50.0	31.0	28.0	28.3	31.4	31.8	36.5	41.0	41.0	28.8	0.0
50.0	50.0	50.0	50.0	50.0	31.0	28.0	28.3	31.4	31.8	36.5	41.0	41.0	28.8	0.0
50.0	50.0	50.0	50.0	50.0	31.0	28.0	28.3	31.4	31.8	36.5	41.0	41.0	28.8	0.0
50.0	50.0	50.0	50.0	50.0	31.0	28.0	28.3	31.4	31.8	36.5	41.0	41.0	28.8	0.0
50.0	50.0	50.0	50.0	50.0	31.0	28.0	28.3	31.4	31.8	36.5	41.0	41.0	28.8	0.0
50.0	50.0	50.0	50.0	50.0	31.0	28.0	28.3	31.4	31.8	36.5	41.0	41.0	28.8	0.0

And here is what I am loading today in my next tune:

0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00
0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00
0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00	0.00
0.00	0.00	0.00	0.00	0.00	20.00	20.00	20.00	20.00	20.00	20.00	18.00	18.00	5.00	0.00
25.00	25.00	25.00	25.00	25.00	25.00	22.00	27.00	33.00	35.00	25.00	22.00	22.00	9.50	0.00
40.00	40.00	40.00	40.00	40.00	27.00	24.00	27.00	33.00	35.00	36.00	32.00	32.00	25.00	0.00
50.00	50.00	50.00	50.00	50.00	28.00	25.00	27.00	33.00	35.00	40.00	45.00	42.00	33.00	0.00
50.00	50.00	50.00	50.00	50.00	28.00	25.00	27.00	33.00	35.00	40.00	45.00	42.00	33.00	0.00
50.00	50.00	50.00	50.00	50.00	28.00	25.00	27.00	33.00	35.00	40.00	45.00	42.00	33.00	0.00
50.00	50.00	50.00	50.00	50.00	28.00	25.00	27.00	33.00	35.00	40.00	45.00	42.00	33.00	0.00
50.00	50.00	50.00	50.00	50.00	28.00	25.00	27.00	33.00	35.00	40.00	45.00	42.00	33.00	0.00
50.00	50.00	50.00	50.00	50.00	28.00	25.00	27.00	33.00	35.00	40.00	45.00	42.00	33.00	0.00
50.00	50.00	50.00	50.00	50.00	28.00	25.00	27.00	33.00	35.00	40.00	45.00	42.00	33.00	0.00
50.00	50.00	50.00	50.00	50.00	28.00	25.00	27.00	33.00	35.00	40.00	45.00	42.00	33.00	0.00
50.00	50.00	50.00	50.00	50.00	28.00	25.00	27.00	33.00	35.00	40.00	45.00	42.00	33.00	0.00
50.00	50.00	50.00	50.00	50.00	28.00	25.00	27.00	33.00	35.00	40.00	45.00	42.00	33.00	0.00
50.00	50.00	50.00	50.00	50.00	28.00	25.00	27.00	33.00	35.00	40.00	45.00	42.00	33.00	0.00

I expect this will considerably smooth out the boost curves, but time will tell.

[AFcadet]

Wow...we have some major pussies here...

Crying that over 16 psi is WAYYY to much at 6,000?

There are many people out there running 19 psi at 6,000 and thye are fine. Personally Im at 18.5 psi at 6,000.

Not to mention darksun was running 24 psi before he went back to stock and popped while he was stock because an oil return line wasnt put on correctly lol

stop acting like YOUR way is the ONLY way. while you may think that 20-21 psi at 4,000 is SOOO CRAZY...there are plenty of people (including myself) that are running that. And we think its fine. We notice there IS a power difference (the turbo is not out of efficiency)...the turbo IS NOT blowing hot air.

Whos right and whos wrong? psh who knows...but dont go tellin people with questions that 16 at 6,000 is the HIGHEST you want to run...when there are so many people obviously running higher then that. Give the information to the OP...and let them decide.

[FreeFlyFreak]

Originally Posted by cld12pk2go Good discussion. Our ECU is certainly not my AEM EMS on my TurboMustang where I just tune the PI loop for boost pressure and it goes right to my target and does not deviate 0.1 PSI. This ECU does a lot of convoluted shit with respect to aiming for torque from various tables. I started tweaking the WG DC in my last map and it appears to have helped somewhat with spikes around 3k. However, I also applied the throttle smoothing fixes on the same map so it could be related to that. I also wait until 3500RPM in all my TRL tables to go to make max load. Here is my latest TRL:

I like your gear specific TRL.
It is very similar to what I seem to be working toward with mine.
The Cobb OTS Gear specific TRL (which seem to be for WOT) seem to be bassackwards to me.
You have them the right way round. I still have more tweaking to do mine are basically OTS with the 5 +6 gears changed to mirror the 3rd gear and works beautifully, but I could definitely do with lowering load targets in 1 +2 to close to grip limits. Pretty much I expect to end up with something very similar to your graph.........
I should just use it as a base and tweak it, would be easier than tweaking the OTS map.


Steve

[cld12pk2go]

Originally Posted by FreeFlyFreak I like your gear specific TRL. It is very similar to what I seem to be working toward with mine. The Cobb OTS Gear specific TRL (which seem to be for WOT) seem to be bassackwards to me. You have them the right way round. I still have more tweaking to do mine are basically OTS with the 5 +6 gears changed to mirror the 3rd gear and works beautifully, but I could definitely do with lowering load targets in 1 +2 to close to grip limits. Pretty much I expect to end up with something very similar to your graph......... I should just use it as a base and tweak it, would be easier than tweaking the OTS map. Steve

Yeah, I don't know WTF Cobb was doing making load 1.94 on 1/2nd gear and 1.7 in 3-6th.

Here is where I am currently:

[fjames]

I've been assuming the high values Cobb uses in 1st and 2nd are just to get them out of the way so to speak. Since the car can't build enough boost in those gears to be a problem, the high values let it do whatever it can.

[FreeFlyFreak]

Originally Posted by fjames I've been assuming the high values Cobb uses in 1st and 2nd are just to get them out of the way so to speak. Since the car can't build enough boost in those gears to be a problem, the high values let it do whatever it can.

I think their thinking is that someone could slap on big slicks at the 1/4 mile and use that power, for me I want it toned down, on my tires I dont want and cannot use that power, it is pointless for me.
I however would like a little more power with the wheel turned in 1+2, do you know the map that controls that, I think some one posted it it one time.

The 5+6 in my OTS map Stage 1+ are weak, too weak, and I have basically initially matched them to 3rd. To start anyway.
I have had to remove a little timing in the high load, high rpm area I was getting some knock in 5+6 on the OTS map pulling anywhere from .5-1.5 degrees where I showed knock seems to have cured it, though further extensive testing is needed.
Plus I am still on 13K stock plugs, I just ordered the 1 step colders.

[fjames]

I don't recall any discussion on the wheel boost reduction - there was some talk of DBW "B" being for TC so people were changing that to be a little more aggressive (so under TC you'd still get some spin.) I did mine a little, but not as much as was posted.

Seems like most of the time I look at an ots map, 5th and 6th are almost untouched - very common to have 1.61 for 5th across the board. I tune for 4th, match 3rd to that exactly, then taper it about .3 to 5th and another .2 to 6th.

Give you an idea, my peak load target in 3rd and 4th is 1.78, 5th is 1.75 and 6th is 1.73. My peak is at 4K and 4.5K. This approach seems to be working pretty well. I've been doing it from the beginning, but lately there's a twist. I went with a taper on the low side, so 2-3.5K are lower than ots by a good bit, and peak is at a higher rpm. This relates to 5th and 6th in a weird way I hadn't thought of ... since I leave everything under peak alone and just taper from peak to redline, my load targets at cruising rpm in 5th and 6th are nicely conservative. I worry about the ecu trying to dump a bunch of boost in a high gear and always had conservative values there, but it's nice to have them sort of "built in" now.

This may all change though. I haven't been able to log for a month or so because my spot is under construction, and my CDI internals failed last week. I just put in replacement KMDs tonight and all is well, but I'm sort of out of touch with my car. So what I'd been doing was getting good at real-time monitoring. What I've been working on is lowering WG, lowering Boost Limits Throttle and such to see how far I can go without affecting performance - building in as much safety as I can to see what happens.

Tonight, checking out the new internals, I got no spike at all from just hitting it in 4th - a first for me. Still a spike on the shift to 5th, but that's to be expected. Problem is I'm not seeing as much boost as usual, and although some of that boost is just from falling off the spike, old logs seem to indicate that I'm low on boost compared to load. So ... maybe I went to far with the WG. It's just fractional, but I'd rather see 18.25 than 17.75 lol.

[FreeFlyFreak]

Originally Posted by fjames I don't recall any discussion on the wheel boost reduction - there was some talk of DBW "B" being for TC so people were changing that to be a little more aggressive (so under TC you'd still get some spin.) I did mine a little, but not as much as was posted.

Hmmmm, maybe I am misremembering.
So DBW B for TC..........
In that case looking at the tables I am going to guess Throttle Requested Load B could be for TC too or possibly for the 1 +2 power reduction with steering input.....
I will not have chance to do any investigating for a couple of days, but if I find it I will start a thread.
There must be a table for the 1+2 wheel turned power reduction........ right?

[evidence]

Originally Posted by FreeFlyFreak Hmmmm, maybe I am misremembering. So DBW B for TC.......... In that case looking at the tables I am going to guess Throttle Requested Load B could be for TC too or possibly for the 1 +2 power reduction with steering input..... I will not have chance to do any investigating for a couple of days, but if I find it I will start a thread. There must be a table for the 1+2 wheel turned power reduction........ right?

Wonder if B is for TC and steering input? Also possible it uses the 'high bat' per gear load tables I suppose? Not really much else it could be, unless the logic is static or Cobb doesn't allow/hasn't discovered that table.