Dynamometers are great tuning and research tools, but they do have their limitations. The primary limiting factor of a dyno is that it’s static. It tests power at the wheels while all other parts of the car are static, which is a condition you’ll never experience on any track we’re aware of.
So you end up getting a highly repeatable …
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Eww canned tunes on track...yikes. I won't run them on the street. Typically just a throttle map and maybe an increase to load or boost targets. The worst of them removing the load based targets and just going boost.
A proper load based tune with more allowance for timing over boost should get better results with less heat. Add a gallon or two of E85 and then you may be able to do both.
If you do spike with some E85 you can bump up any of the pesky IAT/ignition modification tables. You'll get the power back.
The steady state part of tuning is easy- making power is incredibly straight forward. Can take time, depending on the number of variables that need to be dealt with, but it's not hard.
Most of the OEM calibration time is spent on starting and transients. Heck, all of the many thousands of miles driven during development is about transients.
So did these tunes not make more power on the dyno as well? Or are you saying heat soak on the track just negates the gains? You mention that the n55 is already pretty maxed out. I'm sure the MHD claimed numbers are on the highest octane- 95/102 ron and cold car, ideal day. Dipping down to 93, especially on the track if going to lose you some power. I know my s55 was pretty sensitive to heat even on a stock tune. I could see the vmax difference on long straights at Road America and when I had to fill up with 91 instead of 93 the difference was noticeable, even on a stock tune for 91, let alone pushing the poor stock turbo so hard.
Looking at the MHD numbers stage 1 vs stage 2 is 30hp and assumes an upgrade intercooler. That might be a reasonable expectation and mostly due to the intercooler. I think the biggest take away here is that the car has inadequate cooling to support more power.
Andy Hollis said:
E85 is the way!
Not for Tuner it isn't :(
theruleslawyer said:
So did these tunes not make more power on the dyno as well? Or are you saying heat soak on the track just negates the gains? You mention that the n55 is already pretty maxed out. I'm sure the MHD claimed numbers are on the highest octane- 95/102 ron and cold car, ideal day. Dipping down to 93, especially on the track if going to lose you some power. I know my s55 was pretty sensitive to heat even on a stock tune. I could see the vmax difference on long straights at Road America and when I had to fill up with 91 instead of 93 the difference was noticeable, even on a stock tune for 91, let alone pushing the poor stock turbo so hard.
Looking at the MHD numbers stage 1 vs stage 2 is 30hp and assumes an upgrade intercooler. That might be a reasonable expectation and mostly due to the intercooler. I think the biggest take away here is that the car has inadequate cooling to support more power.
Yeah I think that's going to be our first target: getting IAT's down. I concur with zdnet's assessment of canned tunes, but this exercise ws all about finding hurdles before we put the time and expense into doing a custom tune, and those IATs are a big hurdle. I'd love to be able to fill the thing up with corn sauce, but the SCCA says no E85 in the TT Tuner division, so we're stuck with pump 93. Once we feel like the hard parts are squared away, though, BimmerWorld has a great tuner they work with and we'll get them logged in and working on our ones and zeros.
JG Pasterjak said:
Yeah I think that's going to be our first target: getting IAT's down. I concur with zdnet's assessment of canned tunes, but this exercise ws all about finding hurdles before we put the time and expense into doing a custom tune, and those IATs are a big hurdle. I'd love to be able to fill the thing up with corn sauce, but the SCCA says no E85 in the TT Tuner division, so we're stuck with pump 93. Once we feel like the hard parts are squared away, though, BimmerWorld has a great tuner they work with and we'll get them logged in and working on our ones and zeros.
Is that Epic Motorsports?
FWIW, I had great experiences using the canned Epic tune on my E46 M3 for several years. I later had them do a custom remote tune which didn't change the peak power but did pick up about 10 ft-lbs of midrange torque.
...and then later I had them do another custom tune that took ~ 80 horsepower off the top end so that I could race it in NASA ST4. :)
You can easily test intercooler capacity on the dyno - we saw the stock Mazdaspeed Miata drop 15 hp (IIRC) on back-to-back-to-back dyno runs as that factory IC heatsoaked. In fact, the dyno is GREAT for testing heat capacity simply because there is little cooling airflow.
In the article, you talked about the heat sink capacity of the intercooler. I don't think that's really what you're after - more heat capacity just gives you more time until the IC is heatsoaked. What you want is improved heat transfer from the IC to the air. That could be a more efficient core design (not necessarily heavier) or improved airflow. Just throwing a heavy IC in there for sheer mass is not the right solution.
Intercooler or airflow upgrades done right will probably help, but isn't that just a bandaid for a turbo that's now operating further and further out of its efficiency range? Great to be able to cool the charge before it hits the intake manifold, but you'll still be running very high exhaust manifold pressures, turbine inlet temperatures, compressor out temperatures, etc. Probably not an issue on the street, but for significant track use that stuff would be in the back of my head.
The stock intercooler may be enough for a more appropriately sized turbo pushing a few more pounds of boost. At what point does it make sense to make that change first?
gearheadE30 said:
Intercooler or airflow upgrades done right will probably help, but isn't that just a bandaid for a turbo that's now operating further and further out of its efficiency range?
Yes.
Unfortunately, replacing the turbo would propel us into a TT division requiring sawzalls, and we really want to preserve the streetiness of this car as much as possible. So we're trying to find the most efficient band-aids possible at this point because the tiny little turbo on this thing is super efficient, but has very little headspace. We know that we're going to hit a hardcap on power pretty soon, but we're not there yet, so I think it's worth looking for what little low-hanging fruit remains.
JG, looks like you're on MHD rather than the BM3 I'm on, but do they have a "0+" tune? With BM3, as I understand it, it's basically the stock tune from the N55 M2. I'm currently running that one (N55 235i), but haven't yet been smart enough to do any back-to-back sessions on the different tunes.
It feels much more factory, but with better top end, as opposed to the canned tunes that really just feel like they threw all the boost at the bottom end so you can blow the tires off in 2nd gear and say to your buddies "Bruh look how fast my car is now, it won't even hook!"
As I'm currently losing my personal "Don't screw with the street car!" battle and have a catted downpipe on the shelf and am shopping intercoolers, this hits at just the right time.
And I know its just whatever forum algorithm, but seeing New Reader as my status cracks me up, since my subscription could have like a 5 year old by now and it wouldn't even be weird. 
RacerBowie said:
JG, looks like you're on MHD rather than the BM3 I'm on, but do they have a "0+" tune? With BM3, as I understand it, it's basically the stock tune from the N55 M2. I'm currently running that one (N55 235i), but haven't yet been smart enough to do any back-to-back sessions on the different tunes.
It feels much more factory, but with better top end, as opposed to the canned tunes that really just feel like they threw all the boost at the bottom end so you can blow the tires off in 2nd gear and say to your buddies "Bruh look how fast my car is now, it won't even hook!"
As I'm currently losing my personal "Don't screw with the street car!" battle and have a catted downpipe on the shelf and am shopping intercoolers, this hits at just the right time.
MHD has a "Stage 0" but from what I can tell it's pretty much the stock tune but *maybe* with a little more aggressive ignition curve biased toward good 93. But that could be just me getting better/fresher gas. At any rate true stock and Stage 0 seemed within the margin of error.
I'm curious how your DP works out, New Reader Bowie. I think your N55 is factory rated a few hp over ours, too, isn't it? I'd be curious where that bump comes from. Whether it's just a bit more boost, or just on the overboost, or whatever. Overall I'm starting to feel like that N55 turbo is pretty maxed and all any of us are doing is playing in the margins.
We put an intercooler sprayer on a turbo Miata years ago. It's a very DIY-able thing, ours was controlled by a pressure switch - above 6 psi, it would spritz the IC every few seconds.
Coming off track after 20 minutes at Willow Springs in 100F weather, the intercooler was cool to the touch.
Might be a good way to improve the effectiveness of the IC without a lot of effort or weight. Minimum effort version: reroute the windshield washer sprayer to in front of the IC, have the driver trigger it manually on the straights. Datalog and proceed.
Keith Tanner said:
We put an intercooler sprayer on a turbo Miata years ago. It's a very DIY-able thing, ours was controlled by a pressure switch - above 6 psi, it would spritz the IC every few seconds.
Coming off track after 20 minutes at Willow Springs in 100F weather, the intercooler was cool to the touch.
Might be a good way to improve the effectiveness of the IC without a lot of effort or weight. Minimum effort version: reroute the windshield washer sprayer to in front of the IC, have the driver trigger it manually on the straights. Datalog and proceed.
This was one of the first things I thought of... then I looked at the rules and it's specifically disallowed. Boo.
In reply to JG Pasterjak :
Boy, it sure would be a shame if your auxiliary windshield washer tank - mounted up front above the heat exchangers to prevent freezing in the Florida winter - should develop a slow leak mid-race.
JG Pasterjak said:
Andy Hollis said:
E85 is the way!
Not for Tuner it isn't :(
Uggh.
Well you can legally run E15, as that is the current gov't limit for pump fuel. And while it's not gonna cool your beer, it's 50% more E than you have now.
Plus, it's easily within the range where the tune will compensate under close-loop operation. Does that thing even run open loop at WOT? Most modern cars do not.
Is water methanol injection systems not allowd in the TT Tuner class? A properly implemented system setup can bring IAT's down to reasonable numbers. It'll come down to a engine performance gain vs vehicle dynamics (weight) vs $$ budget.
Andy Hollis said:
JG Pasterjak said:
Andy Hollis said:
E85 is the way!
Not for Tuner it isn't :(
Uggh.
Well you can legally run E15, as that is the current gov't limit for pump fuel. And while it's not gonna cool your beer, it's 50% more E than you have now.
Plus, it's easily within the range where the tune will compensate under close-loop operation. Does that thing even run open loop at WOT? Most modern cars do not.
Given the tools, running closed loop at WOT is far better than open loop. The problem is that it's likely running too rich for LBT so that it cools other engine hardware down.
But it would be an option to correctly lower the WOT fuel target- the LBT power given up could be made up by knock mitigation from cooler combustion.
Great article, super intriguing. What is missing is the dyno numbers with the alternate tunes. I'm dying to know what the dyno says with the high boost tunes that did not work. On the first pull and after several pulls getting some heat soak. It's not too late to update the article... Just in case you are bored and wondering what to write about next!
My dyno tuner commented on my intercooler, he noticed that it worked better than many he sees come through the shop after we made many pulls. By the way if in KS needing dyno help, Jesse Prather really knows what he's doing. GRM definitely knows who he is. So anyway, the dyno can help to see such issues, as another person commented. But maybe there would still be a discrepancy, so let's see the data!
All the best and keep up the good work
Rob
rwinter1 said:
Great article, super intriguing. What is missing is the dyno numbers with the alternate tunes. I'm dying to know what the dyno says with the high boost tunes that did not work. On the first pull and after several pulls getting some heat soak. It's not too late to update the article... Just in case you are bored and wondering what to write about next!
My dyno tuner commented on my intercooler, he noticed that it worked better than many he sees come through the shop after we made many pulls. By the way if in KS needing dyno help, Jesse Prather really knows what he's doing. GRM definitely knows who he is. So anyway, the dyno can help to see such issues, as another person commented. But maybe there would still be a discrepancy, so let's see the data!
All the best and keep up the good work
Rob
So we actually haven't been to the dyno yet, as just based on the speed traces we figured it would be a waste of resources until we managed to produce repeatable, consistent performance.
The good news is an ungraded intercooler seems to have solved—or at least heavily mitigated—our issues with IAT and the tunes are now actually working. I was doing some experimentation at TTN/UTCC, and I'm heading to the FIRM this weekend for some actualy track confirmation, then I'll book some dyno time now that I know it's worth spending the resources.
Given the IAT data I would speculate the the upgraded intercooler would be worth it, even if it means hanging an extra 20lb on the nose. The car weighs what like 4000lb? You probably wouldn't even notice it.
Thread title made me think "oil starvation in corners" but I see that's not even close to the subject.
bighoward said:
Is water methanol injection systems not allowd in the TT Tuner class? A properly implemented system setup can bring IAT's down to reasonable numbers. It'll come down to a engine performance gain vs vehicle dynamics (weight) vs $$ budget.
Its stock on the GTS, not excluded, so 'legal'. I don't see anything that would allow it to be added however. You'd need to be in Max for TT it looks like. Alternate classing entry looks like MAX as well
