tuning tips

[jackerman]

Hey tmers, i just started tuning my daytona and it doesnt seem to be pulling as hard as it should in my opinion. I have stock garret turbo fm 5 cal 255 pump plus 40 inj. I currently have boost 18 low tens on wideband timing at 12 deg. I have checked cam distributer and crank timing and its all on the money. The car from a role in second doesnt even break the tires loose and it use too before i freshened up the motor. What other things should i be looking for

[glhs875]

For one it is running too rich. Maybe lean it out to mid 11's and see what it feels like.

[jackerman]

Is that ok to do on pump gas. Thought it was alittle greedy. Ill try it thanks

[glhs875]

Is that ok to do on pump gas. Thought it was alittle greedy. Ill try it thanks

Shouldn't have any problems at say 11.5 to 11.7 AFR. If you do, need to take a good look at the charge temp or ignition timing issue. But with base timing set at 12deg that should be safe at 18 psi if you are using a 3bar map setup and sounds to me that you are.

[jackerman]

I am using 3 bar set up. What would the charge are do. Would that pull extra timing.

[glhs875]

Yes if it is reading high it could end causing detonation which could and should result in timing being pulled.

[jackerman]

Oh ok. If that is the case how do you check it. Ohm it out sorry for dujmb question but im not sure so i figure better to ask while we are on subject

[glhs875]

Easiest way is with some type of scanner that reads live data. One can see what goes on with such a device.

[tryingbe]

Do you have a wideband sensor installed?

If not, you'll need to do that first.

[glhs875]

I have one to install (AEM) once I get my car up and going again. I was making due with reading off a narrow band.

- - - Updated - - -

Do you have a wideband sensor installed?

If not, you'll need to do that first.

He mentioned he was using a wideband in a previous post.

[1BADVAN]

I am using 3 bar set up. What would the charge are do. Would that pull extra timing.

The Charge air temperature sensor is a very low tech and inaccurate way of trying to read the temperature of the air in the intake. It is inaccurate because after the engine is war it usually just reads the temp of the intake itself and not the air flowing through it.

It is designed to richen the fuel mixture in lower temps to keep a more accurate A/F mixture.

[1BADVAN]

Hey tmers, i just started tuning my daytona and it doesnt seem to be pulling as hard as it should in my opinion. I have stock garret turbo fm 5 cal 255 pump plus 40 inj. I currently have boost 18 low tens on wideband timing at 12 deg. I have checked cam distributer and crank timing and its all on the money. The car from a role in second doesnt even break the tires loose and it use too before i freshened up the motor. What other things should i be looking for

With low 10s on A/F it shouldn't make it to slow but bumping it to low 11s should be a noticeable increase in power.
What year is your Daytona? -what type of ECU does it have? LM SMEC SBEC?

What have you recently changed? all that you listed?

[5DIGITS]

The Charge air temperature sensor is a very low tech and inaccurate way of trying to read the temperature of the air in the intake. It is inaccurate because after the engine is war it usually just reads the temp of the intake itself and not the air flowing through it. It is designed to richen the fuel mixture in lower temps to keep a more accurate A/F mixture.

This is very true for the original units but correctable.
Install an open cage sensor to address the issue.
The transient response will then become as active as the TPS sensor while measuring air temp rather than manifold temp.
Search RockAuto, Autozone, etc... while viewing the pics to insure that its an open cage sensor rather than 'impregnated' plastic.
Note: depending on the sensor manufacturer the connector may need to change, for key and blade/pin compatibility.

[jackerman]

Its 89 shelby t2. I have fwd 5 cal. All that i recently changed is back cut valves and arp everything. Car was a rocket before well butt dyno. I had fuel washed the rings and started burning lots of oil. Afe all charge air sensors the same threads

[jackerman]

Wow. I have been lowering fuel pressure in very small increments and wow 10.5 on wide band one fixed boost leak just killed the tires. Know to figure if i should do more boost or lower fuel pressure.

[glhs727]

what is your current boost level now? if below 15 psi. I would turn up the boost in small increments. shoot for 11.2-11.5 at 20-25 psi of boost

[jackerman]

Boost was somewhere around 18. Ill bump it up slow. Do you think in 20 or higher boostill need to lower the timing to keep from getting knock.

[glhs727]

Boost was somewhere around 18. Ill bump it up slow. Do you think in 20 or higher boostill need to lower the timing to keep from getting knock.

as boost goes up, timing is being retarded through the computer. I would raise the boost to 22 psi and see where you are at, you still might need to take out some fuel. It would also be good to hook up a scan tool and see if the computer is picking up any knock, and if so it is it pulling timing as a result. if not, you are good to go. Also when you are at the high end of the rpm scale and max boost, don't worry if the a/f creep to 11.8 or so, that's still fine, and don't wory about a/f in the 12-13 range when you are first getting into boost (under 8 psi) as the motor isn't really under tremendous load. report back your results!

[jackerman]

Ah got some time to play with car. 20 psi boost 10.8 wideband pulling real good to me. One last question first gear this thing winds up to about 7000 rpm. Does it so quick. I only have stock t2 rods with everything held together with arp fasteners. Makes me a little nervous to rev that high. Should i be looking into a rev limiter or just shift faster instead of allowing the wheel speed to catch up before shifting.

[cordes]

I would just shift sooner. Once you're making good power 1st gear is pretty much useless on the street.