How not to tune your turbo miata

blackster · Postby **blackster** » Wed Oct 03, 2007 9:38 pm

Taken from a US miata specialist, that dyno tuned an american SE.

Modifications done:
Xede w/ 560 cc Injectors
Turbo compressor Wheel Upgrade
Custom Exhaust
BEGi Downpipe w/ CAT Bypass
BEGi Throttle Inlet Tube
Forge Bypass Valve

Spot the problem?

Locutus · Postby **Locutus** » Wed Oct 03, 2007 9:53 pm

that graph doesn't make any sense.

blackster · Postby **blackster** » Wed Oct 03, 2007 10:09 pm

Locutus wrote::? that graph doesn't make any sense.

Nope, try again?

JBT · Postby **JBT** » Wed Oct 03, 2007 10:51 pm

Lean running?

blackster · Postby **blackster** » Wed Oct 03, 2007 11:01 pm

JBT wrote:Lean running?

Winner..............

JBT · Postby **JBT** » Wed Oct 03, 2007 11:09 pm

Hmmmm......could be nasty. :shock:

Sean · Postby **Sean** » Wed Oct 03, 2007 11:35 pm

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

mid 12s isn't too bad, although i have seen MX5s tend to like more fuel and timing rather than lean and less timing...

sabretooth · Postby **sabretooth** » Thu Oct 04, 2007 12:35 am

Mid 12s doesn't seem too bad to me?

blackster · Postby **blackster** » Thu Oct 04, 2007 1:00 am

Sean wrote: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

ampz · Postby **ampz** » Sat Oct 06, 2007 8:08 am

He needs an o2 clamp

blackster · Postby **blackster** » Sat Oct 06, 2007 12:48 pm

ampz wrote:He needs an o2 clamp

Not just that,

Considering the mods and the 105 octane gas used, those numbers are not impressive and relatively lean. Using premium pump gas 230-240rwhp can be seen with a AFR of 12:1 - 11:3 with ignition control.

ampz · Postby **ampz** » Sat Oct 06, 2007 3:54 pm

230 is impreseive.

But how would he go with emissions with an 11 AFR?

(I'm not saying it is a good tune, just curious)

blackster · Postby **blackster** » Sat Oct 06, 2007 9:30 pm

ampz wrote:230 is impreseive.

Not with a turbine compressor upgrade, the stock IHI puts that kind of number when pushed.

But how would he go with emissions with an 11 AFR?

(I'm not saying it is a good tune, just curious)

Being that its a MSM and that car is from texas and was tuned there, I dont believe they are stringent as say california which requires yearly emission testing.

Where emission testing is required they do what exactly what alot of people do here, they lean them out for testing or some cases remove aftermarket EMS and injectors and run OEM ECU during testing.

From whats been shown so far, MSMs leaned aggressively = blown headgasket.

A stock SE runs an AFR of 10.5

The Pupat · Postby **The Pupat** » Sun Oct 07, 2007 10:37 pm

Looks fine to me.

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

blackster · Postby **blackster** » Mon Oct 08, 2007 1:45 am

The Pupat wrote: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.