i know it can be really bad headache when turbocharging the car. as of now, im trying to turbocharge S as soon as i get one. so im gathering as much as information about turbo stuff i can.

i have tons of question on turbo system but im gonna make it simple and not make u do 3 pages of writing.

so the question is when u guys say tune the car after installation of turbocharger, wut exactly do u mean?

i dont think it;s about spark plug and ignition coil stuff like any other basic tuning.

my guess is controlling the fuel and air pressure due to boost right?

can someone nice enough to bear my ignorance help me out on this one?

thanks for further replies.

 

If you are going turbo you better have deep pockets..

 

Or find someone who's bitten off more than they can chew and pick the parts up for a song!

When we say tune we're referring to air/fuel and ignition timing. If you shove more air into the engine you have to supply an appropriate amount of fuel. The stock ECU isn't designed to go above ambient pressure and so causes problems under boost. It retards igntion drastically and can even behave erratically.

The two commercial supercharger kits use a combination of tricking the ECU into not seeing boost, and upping the pressure on the injectors proportionally to the boost. Works quite well as the boost from the SC is proportional to RPM (hence predictable) and not very high (max 7psi).

Turbos are exhaust driven so not directly proportional to RPM. And in general provide more boost lower in the RPM range. Redneck tricks like boost dependant fuel pressure regulators are just not up to it. If you run lean your engine knocks. That very quickly results in either massive retard of igntion (and very little power) or a blown engine. You need both a good A/F and slight retardation of ignition to avoid one or both of these happenings and to achieve performance and safety.

You can achieve this with a piggy back ECU like the E-manage, or better still, the AEM replacement ECU. When I say you, I mean you and your highly experienced tuner with dyno and wideband A/F metering.

For more info do a search for turbo and Wesmaster. Wes has been sent by Turbous (the ancient god of unnecessary engine modifition) to show us all what not to do on the road to FI heaven.

 

Yes $36,000 into my Turbo is more than I can chew..

 

AusS2000 u r saying ignition timing has to be readjusted since it's using exhaust circulation power, which isnt related to rpm?

and it's preferred to stick with AEM ECU?

 

Yes, 500HP..TURBO yours cost $36,000 but then again you didn't have a "normal" system.

Turbo systems can be built for much less, of course they will perform much less also (than what you were trying for)

ZooMonkey what are your performance goals?

There is one level of performance that can be met with a rising rate fuel pressure regulator.

There is another level that requires some control.

There's another level that requires full controls.

And then there is the 500HP..Turbo level

 

What David b said.

The SC kits 'get away' with it because they aren't pushing the envelope too far.

As sson as you push any further, or work with anything less linear (a turbo) you need all the control you can get. You need to be able to tune your fuel for much higher ranges and relate it to boost as well as RPM and load. You also need to be able control ignition so you can get optimal power (that's why you're doing it I guess) with maximum safety.

 

Just get the new gears 4.56 and 4.77s does wonders for the car

 

Even when the sc owners tries to push a little more like 10-11 psi
most of them go with aem to keep things under control.

 

The AEM is harder to tune but just as good if not better than the easier to tune E-Manage.