How not to tune your turbo miata

[The Pupat]

Looks fine to me.

I reckon you need to learn more about tuning cars before commenting on others ability.

I dont claim to be an expert, far from it. I think i have tinkered around with my car enough with the aid of haltech and seen other SE's to know what works and what doesnt.

13's isn't lean.

12-13 is acceptable for a turbo car (you can go leaner again if you want and NA it's normally accepted anything up to high 13's is acceptable).

You'll find that the leanness in the start of the chart is from lowish throttle input as they are ramping the car up. On a dyno with a turbo car you have to have the turbo spooled when you hit it otherwise it won't work properly. The little spike and the end of the graph would be from backing off. The map looks alright for an interceptor which is always going to be a bodge job compared to completely retuning the car.

[blackster]

You'll find that the leanness in the start of the chart is from lowish throttle input as they are ramping the car up.

14.1 @ 3500-4000rpm is not lowish throttle on a SE, at 4000rpm the SE is almost at full boost. At the beggining of the power run (60km/h in 4th) the SE is sitting at around 2000rpm

12-13 is acceptable for a turbo car (you can go leaner again if you want and NA it's normally accepted anything up to high 13's is acceptable).

I am not refering to an NA, I am refering to an SE which that car is. If you scroll back a few posts I do explain why it isnt a great tune and what that intecerptor fails to take into account (lean hesitation spike).

As far as the numbers are concerned, a intercepted SE can make 230rwhp with an AFR from 12.1 to 11.3 using premium pump gas and thats without the turbine compressor upgrade.

Turbine clip upgrade (hi flow) along with 100+ (US = ROM+2) octane gas report numbers of upto 250rwhp with a very similar AFR and timming control to 230rwhp. Leaning harder hasnt shown much hp/torque increase but more importantly it has shown detonation/pinging with a few blown headgaskets along with it.

235rwhp (with hi flow) AFR 14.1 - 12.1 - 13.1 - 12.1 using 100 US octane
vrs
230rwhp (non hi flow) ARF 12.1 - 11.3 using 93-95 US octane.

Something isnt right with that tuned dyno graph.

[Sean]

Perhaps it not underfull load at the early part of the graph?

The SE IHI starts spooling at about 2500rpm and its not very long until its in full boost.

Reading those AFR numbers

3500-4000rpm = 14:1
4000-5000rpm = 12:1
5000-6000rpm = 12:1 - 13:1 - 12:1

The other problem is that with most piggybacks like the above, is that it doesnt address the lean hesitation experienced by the MSM on transition into boost. The hesitation is a result of the stock ECU trying to run stoich (14.7) A/F ratio during this transition and will not show up on a dyno run as its load based.

ObdII scanner reading the 02 signal.

This MSM is experiencing a double wammy

We can't be sure it was under full load, regardless of RPM as we don't have all the engine readings, I just don't think we should be so hard on someone when we don't know the full situation, I've been involved in lots of turbo car tuning, including my own turbo MX. Geez, there is even a chance that the o2 sesnor on the dyno was shoddy.

[Brett_MX5]

So what is the ideal AFR for the SE ??

[Sean]

So what is the ideal AFR for the SE ??

There is no such thing as ideal, it varies depending on what youwant from the car, the tune (including all aspects not just fueling) that makes the most power, may not see the car make it to the other end of the track..

[The Pupat]

So what is the ideal AFR for the SE ??

There is no such thing as ideal, it varies depending on what youwant from the car, the tune (including all aspects not just fueling) that makes the most power, may not see the car make it to the other end of the track..

exactly. Zoom had a 4 page article where they interviewed Simon Gishus From Nizpro about AFR ratios and tuning cars. Suffice to say tuned properly an XR6 Turbo made within 3hp on an engine dyno with the AFR between 12 and 14, but you had to modify the tune to make sure it was safe. There is no such things one singular ideal value in tuning a motor, this is why it's hard to find a good tuner.

blackster: it'll only be a full boost if the pedal is at WOT. There are any number of reasons why that AFR could be high at those RPM ranges and the tune could still be good.

[blackster]

exactly. Zoom had a 4 page article where they interviewed Simon Gishus From Nizpro about AFR ratios and tuning cars. Suffice to say tuned properly an XR6 Turbo made within 3hp on an engine dyno with the AFR between 12 and 14, but you had to modify the tune to make sure it was safe.

What you said about XR6 turbo doesnt make sense, care to elaborate?

With optimal timming control would you lean a car further (ie into the 14s) just to get 3 hp more, at the expense of a head gasket?.

blackster: it'll only be a full boost if the pedal is at WOT. There are any number of reasons why that AFR could be high at those RPM ranges and the tune could still be good.

Isnt that what your doing on the dyno, roll it in 4th at 2000rpm then go WOT to redline?

Stock SE dyno graph data stats

3000rpm 5 psi load 42.7 %
3500rpm 6 psi load 43.1 %
4000rpm 7 psi load 44.3 %
6500rpm 7 psi load 44.5 %

Intercepted SE

3000rpm 10 psi load 43.7%
3500rpm 11 psi load 44.5%
4500rpm 12 psi load 44.7%
5000rpm 13 psi load 45.3%
6500rpm 13 psi load 46.3%

I stick to my original comments that is not a good tune for an SE, regardless of what +/- igntion they are using.

[Woo]

Isnt that what your doing on the dyno, roll it in 4th at 2000rpm then go WOT to redline?

Not being picky, (actually enjoying the to-an-fro in this thread) but arent the SE's 6 speeders? So it would be roll in on 5th gear and WOT2RL?

[blackster]

Isnt that what your doing on the dyno, roll it in 4th at 2000rpm then go WOT to redline?

Not being picky, (actually enjoying the to-an-fro in this thread) but arent the SE's 6 speeders? So it would be roll in on 5th gear and WOT2RL?

If they were trying to find a 1:1 gear ratio then I believe it would be 5th gear.

SE gearing

1st 3.760 / -
2nd 2.269 / -
3rd 1.645 / -
4th 1.258 / -
5th 1.000 / -
6th 0.843 / -
FD 3.636

Comments from haltech as to why they use 4th gear.

A. Firstly to keep power sheets consistent between all vehicles.
B. You also want the power run to make the most power
at around 120km/h.
C. 5th gear will cause the run to finish at well over 200km/h in most vehicles. This is not acceptable as most dynos do not recommend to run at over 200km/h due to balance / wear / safety issues.
D. The car will be unnecessarily loaded for a longer period of time under each power run if done if 5th gear.

[Brett_MX5]

I shall rephrase

What would be the leanest value you could go on a stock SE at full boost/WOT ?

Or what AFR was used to blow a head gasket ?

Obviously my car will be different to everyone elses regarding tune and what I want from it - but having a figure to watch out for would be better than finding out the hard way

[Woo]

What a crock from Haltech !!!!!
All the dynos I've been on are rated at least 300 kph
The multiplicative factor of the gearing artificially inflates the torque and power figures when done in the lower gear..... Makes them look good though I suppose.

[blackster]

What a crock from Haltech !!!!!
All the dynos I've been on are rated at least 300 kph
The multiplicative factor of the gearing artificially inflates the torque and power figures when done in the lower gear..... Makes them look good though I suppose.

There must be a difference of opinion then because my SE along with alot of other 6 speeds have seen the rollers of dynodynamics, mainland and dynojet (non haltech) in sydney which happen to use 4th gear.

As for the multiplication factor and gearing.

Theoretically, the results should be the same regardless of what gear is used because the increased torque in the lower gears is cancelled by the decreased speeds. In the real world, there are always differences between the gears, and the differences can be explained by a number of factors.Because of nasty things like friction and inertia, different gears always have different amounts of drag, and the greater the reduction or increase in the gearbox, the greater the drag.

A low gear may fly the engine through the rpm range so quickly that it never has a chance to build up any helpful intake and exhaust resonance that those header engineers spend so much time trying to achieve. Fifth gear may be spinning your drivetrain so quickly that significant increases in gearbox drag are created. Third and fourth gears are usually favorites for finding your actual horsepower, and testing all of the gears is a useful method for discovering problems in your drivetrain.

What i am finding ironic is that we have non SE owners, who clearly no have no concept of the cars dynamics commentating on how it should be tuned.

As far as Haltech is concerned, I have been more then impressed with there commitment. Knowing all to well the 100s of dyno and race track hours spent with its tuners to fine tune there products; but also addressing hardware components like alternator field control and engine imbolizer overide with there standalone products.

[Blue94t]

I am with Woo on this one.
Every dyno run I have ever done they normally aim for 1:1 or the closest available. 4th in most gearboxes except some 6 speeds or close ratio boxes.
Given the variation in dyno results I personally only use them as comparitive tuning tools. That is unless you are in a dyno comp where everyone is running back to back.
Jake

[The Pupat]

What i am finding ironic is that we have non SE owners, who clearly no have no concept of the cars dynamics commentating on how it should be tuned.

Here we go, just because I don't own your precious 'SE' doesn't mean I don't have some idea of how to tune a car, not saying that I do but I think I have a reasonable idea on what's involved what you can and can't do and the physics involved. What I do know is that it's an incredibly difficult thing to do and as such it's normally best not to comment on someone elses tune unless you have all the facts. All engines are the same basically. There is no magic but at the same time there is no magic formula, there is a thousand ways to solve the problem.

exactly. Zoom had a 4 page article where they interviewed Simon Gishus From Nizpro about AFR ratios and tuning cars. Suffice to say tuned properly an XR6 Turbo made within 3hp on an engine dyno with the AFR between 12 and 14, but you had to modify the tune to make sure it was safe.

What you said about XR6 turbo doesnt make sense, care to elaborate?

With optimal timming control would you lean a car further (ie into the 14s) just to get 3 hp more, at the expense of a head gasket?.

As for this I can't completely remember the article. but he tuned the car to run 12.6:1 (.86 Lamba or spot on perfect) and made X hp, he then retuned it to mid to high 13s removed timing (becuase you actually lose power when you richen the fuel up) and it made with in 3 hp on an engine dyno, they had a mic on it to check detonation etc so the tune was still spot on and safe but was now tuned to use probably 5% less fuel at full power which can be a significant saving. Keeping in mind that it would likely not blow headgaskets any more or less since what normally kills headgaskets is detonation.

You can't tell a good tune from 1 power run dyno graph. The real art in tuning is in 99% of other time spent in the other regions of the map.

Ohh and give you an idea on how lean you can go, a factory 2JZ-GTE in an Aristo runs 14.7 AFR up till 8psi of boost.

[Sean]

What i am finding ironic is that we have non SE owners, who clearly no have no concept of the cars dynamics commentating on how it should be tuned.

Here we go, just because I don't own your precious 'SE' doesn't mean I don't have some idea of how to tune a car, not saying that I do but I think I have a reasonable idea on what's involved what you can and can't do and the physics involved. What I do know is that it's an incredibly difficult thing to do and as such it's normally best not to comment on someone elses tune unless you have all the facts. All engines are the same basically. There is no magic but at the same time there is no magic formula, there is a thousand ways to solve the problem.

Agree with The Pupat, I've been playing woth turbo cars since before the SE was even released, My 1.6 made more power on an internally stock engine (all unopened block and head) then I've seen an SE make, at one pint it was making 4-5 times the stock power and was actually returning better than stock fuel economy.

The car has been on a truckload of dynos and tuned for a few different set-ups. I'm fairly sure what I've learn in the last few years qualifies me much more than simply owning an SE would.

At the end of the day, you may be right about the tuning be out, but you might also be wrong.

Only time I have openly bagged a tuner is when I was walking down teh driveway to his shop and could hear a car pinging quite badly, the car was clearly under high load, yet the so-called tuner kept on it hard rattling the thing away...

Not much later the engine popped, I'd be blaming that one on poor poor tuning, much to my suprise the customer went back to the same tuner!