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jtothawhat 10-17-2010 03:17 PM


Originally Posted by Savington (Post 644421)
Pictures of the inside of your valve cover, please. Specifically around the area where those two breather lines are. :)

Damn man, didn't take any but it is where the baffle is, so far it's working great. Next time I pull the cover I will snap some pictures for you.


Originally Posted by spoolin2bars (Post 644422)
but like others have said, power under the curve in YOUR power range wouldn't help him at the drag track at all. if he runs a 8500 rpm redline, spending time and $$$ making power from 4-6k would be stupid as he would never be under 6k down the 1/4 mile or launching.

True, and on the highway I brake boost anyway and I launch at 5,000 at least. So it works for me. Power under the curve would be great if I road raced the car and even on the road normal driving my car is a blast! I don't care what the dyno says it has plenty of power just cruising and if anyone in my area wants a ride I will have no problem taking them!

Faeflora 10-17-2010 06:47 PM

Any interesting highway pull conquests?

Gone up against a z06? Curious how you'd do cus of traction.

jtothawhat 10-17-2010 06:53 PM

What year Z06? I walked one with my last set-up like a 01 Model...I would like to run a new LS7 Z06.

Faeflora 10-17-2010 07:47 PM


Originally Posted by jtothawhat (Post 644492)
What year Z06? I walked one with my last set-up like a 01 Model...I would like to run a new LS7 Z06.

Yes the new ones. I went against one when I had 190hp and he was gonnnnee in a second.

Joe Perez 10-17-2010 07:51 PM


Originally Posted by miata2fast (Post 644389)
I would rather drive the car with the red graph lines.

I'm torn here.

I respect the shit out of what jtothawhat has done here. Being able to say the words "425 HP" and "1.6 Miata" in the same sentence is nearly unfathomable.

But as a daily driver? I honestly think I'd go for Sav's setup. Calculate the area under the curve- it's much larger.


Originally Posted by miata2fast (Post 644389)
Have you ever driven car with a really high reving big cammed motor? You adjust your gearing accordingly.

You'd also need a twelve speed gearbox, if we're doing an apples-to-apples comparison.





Originally Posted by Savington (Post 644322)
It's cool, but not all that advanced IMO. All it does is run fuel maps that are 4D instead of 3D - the Z axis is percentage of ethanol in the tank.

Is it really necessary even to do this?

Comparing straight gasoline to straight ethanol, there's a fixed multiplier with which you can compare and convert any of the important properties between them, be it energy per unit volume, volumes of air per volumes of fuel required to achieve ideal lambda, etc. So once you know (thanks to the sensor) what the ratio of gasoline to ethanol is in the tank, you should then simply be able to apply that multiplier to the output of the fuel pusewidth calculation, as is done on most ECUs with compensations for battery voltage, coolant and air temperature, air density, etc. In the Megasquirt world, this is the Gammma variable.

What I am not 100% certain of is whether there exists a linear relationship between fuel composition and ideal spark advance as the ratio of gasoline to ethanol varies. So far as I know, the MS's FlexFuel code does make this assumption.



128x128 maps are asinine and excessive, but a great way for tuners to rip people off I guess.
That was pretty much my reaction when I read that as well. If you have a 128x128 table in which there is significant inter-cell variation which is not able to be approximated by inter-cell interpolation on a 16x16 table, then something is very wrong.

I mean, let's say that you're running an 8,000 RPM redline and 30 PSI of boost. Do you really need to have individual cells every 62.5 RPM and 0.35 PSI?

I can't imagine having to deal with a table that large.

jtothawhat 10-17-2010 08:06 PM



It got to dark to get a good video of the car making a pull, but here is the car at idle cold, it idles a bit higher once it's fully warm.

18psi 10-17-2010 08:14 PM

now THAT'S what a 4 cyl needs to sound like :D

18psi 10-17-2010 08:14 PM

need vids of WOT 3-4th

chicksdigmiatas 10-17-2010 08:25 PM


Originally Posted by 18psi (Post 644536)
need vids of WOT 3-4th

I am with cool guy, i want these like meow.

Savington 10-17-2010 09:14 PM


Originally Posted by Joe Perez (Post 644528)
Is it really necessary even to do this?

Comparing straight gasoline to straight ethanol, there's a fixed multiplier with which you can compare and convert any of the important properties between them, be it energy per unit volume, volumes of air per volumes of fuel required to achieve ideal lambda, etc. So once you know (thanks to the sensor) what the ratio of gasoline to ethanol is in the tank, you should then simply be able to apply that multiplier to the output of the fuel pusewidth calculation, as is done on most ECUs with compensations for battery voltage, coolant and air temperature, air density, etc. In the Megasquirt world, this is the Gammma variable.

You might be able to make it work. The trick is that the ideal AFRs will change based on the percentage of ethanol, and that relationship won't be linear because you can safely run leaner mixtures when using E85. I would tune a race gas track car to 11.4:1, I tune my E85 car to the low 12s. Still can't make it ping at 17psi unless I push way, way past MBT.

The other question is whether you would need more fuel at idle vs. WOT to compensate for stuff like wall wetness, latent heat of vaporization under boost, etc. A quick glance at my 100 octane maps vs. E85 maps shows that I'm either losing fuel pressure at high RPM and high boost (walbro 255HP, unlikely but possible I suppose), or the motor wants a lot more fuel up top after the switch.

A quick google search turned up folks that said the setup is as simple as doing a gas tune and an E85 tune and clicking a button to let the ECU interpolate between the maps based on ethanol content in the tank. This would lead me to believe that a shop charging $3000 for setting it up is less than scrupulous, but I'm not a proEFI dealer so I have no idea how difficult the setup actually is.

As convenient as flex fuel is, I cannot ever imagine paying $3000 for the pleasure. If you must, have two separate AEM tunes and a test port/drain valve on the fuel feed line so you can drain the tank when necessary.

jtothawhat 10-17-2010 11:53 PM

Sav I get what you're saying, I could do something like that--but it isn't very street friendly. I may just run E85 on this ECU and carry an extra 5 gallons in the trunk just in case, and just spend that extra money on other things such as wheels and body work. Either way, next on the list is a 949 twin disk, Quaife Trans, ATI Damp, 6UL wheels, Carbon Mirrors and a OEM lip...maybe a respray. I really need some sponsorship lol

18psi 10-18-2010 12:06 AM

Dude how much/far do you drive to be that scared of running out of e85?

I don't understand it when people say that.

If the nearest station is 20 miles away and its the only one then ok, I get it, but if not, then what is the problem?


I may be spoiled having 3 within 5 miles of my house and 2 within 5 miles of my work, but even if that wasn't the case its not that bad.

Unless you take long ass drives for hours and go 100 miles away I don't see it being a problem big enough to warrant a 6k ecu/tune.

You fill up, drive car, get to quarter tank start thinking of filling up (if its that hard for you to find e85). Quarter tank gives you at least a good 60 miles or more of distance to find e85 assuming you don't pound on it all the way there.



again, I might be spoiled having it easily available. I dunno

jtothawhat 10-18-2010 12:19 AM

Well actually I have a few E85 stations within 10 mins from my house, the closest is 2 miles away. lol But then you have to worry when they switch to winter blend E70, and it's never consistent at all etc. Just a lot of variables it seems like to me, but maybe I am just over thinking the whole thing.

Faeflora 10-18-2010 12:37 AM

You could also just run pump gas :P

jtothawhat 10-18-2010 12:43 AM

I could and not make anymore power then I am now lol

I have a number in my head, which is 600 whp. So, in theory I will not be happy until I make it.

jbrown7815 10-18-2010 01:16 AM

Sorry if I missed this but what fuel were you running for the 425whp dyno?

jtothawhat 10-18-2010 01:45 AM

93 Shell pump.

wittyworks 10-18-2010 02:13 AM

it seems like the smarter way to go (and it seems like everyone is starting to convince you as well) to just keep the aem and spend the money on other important parts to make the 600 hp 1.6 a reality. The bottom line is that you in no way need that heavy duty of an ecu, and for long trips your options would be, extra gas can in trunk, load a pump gas map, or plan to have e85 stations. That just sounds like the smart way to go when you have your current ecu almost dialed in, and you're a few parts away from the most badass 1.6 miata in probably the world.

Savington 10-18-2010 02:38 AM

1 Attachment(s)
OK. No pissing match, just straight comparisons to help you improve your setup.

Here's a comparison from your setup to Eliminator's setup. IIRC, this chart was done on an RM 2 liter, 50trim T04E, .63 stg3 hotside. A little more displacement, but not nearly enough to justify the difference. He made 508whp at 23psi, ~576 at 30psi, and was still able to obtain excellent under-the-curve torque. I put my torque curve in as a comparison - the difference between green and blue is the difference I expect to see when you go from a ~400whp capable turbo to a ~600whp capable turbo. The red line is what I would expect to see on an 800whp capable turbo, not a PTE5857.

Attachment 193499

This is a great thread, full of same-day same dyno comparisons of a bunch of different turbos. 30R, 35R, HTA-wheeled 30 and 35Rs, and the PTE5857 is in there as well. Looks like it spools about as fast as a 30R, but delivers much better flow up top.

Page 4 has the PTE5857 chart. http://motorgeek.com/viewtopic.php?f=14&t=34852

What I'm trying to say is that your setup could be a lot better - you should be able to deliver the same power you have at least a thousand RPM earlier without changing the top-end you have now. Something in your setup isn't cutting it.

miata2fast 10-18-2010 07:54 AM

When I see the dyno graphs, it does look to me like jtothawhat's timing and or fuel settings need work on the lower end.

jtothawhat..Shim under lifters are very light weight lifters with shims that go between a post and the valvestem underneath the lifter. On a 99 solid lifter, you can see how the shim sits on top of the lifter. The cam comes in contact with the shim first. 1.6 hydralic lifters would look like a shim under lifter if you just pull the valve cover and look in. You would have to pull the cam and lifter and flip the lifter upside down. It would be much lighter too.

Also, I am suprised that you do not have a damper yet. Do you have a good oil pump? What port work have you done to the head? Be careful and make sure you have all the safegaurds before you crank up the RPMs.


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