Boost Versus Timing

[vspecll]

Hi all, I think this is a very good topic if people can give some input.

Do you know the amount of total timing you are running at full boost and what power you are making?

eg : R33 GTR 18psi / 20degress timing. 270rwkw.

I am triing to work out if I drop some timing and run more boost. I am also trying to work out where some of these huge power figures are coming from? I have raced a few big hp cars ( over 300rwkw with proof) and still have the faster car. ( I don't have any torque figures).

Theory says more timing the better and the sign of a well built motor is being able to run heaps of timing.

I have seen plenty of cars on dyno's run a big figure once then every other run get's lower and lower as heat soaks in, showing they are really at the edge.

I know all my temps - exhaust,inlet, water,oil, - hardly break a sweat at my current tune after 6 back to back power runs. Maybe Im not pushing it hard enough?

Or is this just a case of dyno reading wars.

What do you think?

Please, lets get some constructive info going.

[LNEMUP498HP]

hello

Many people have different views

Many tuners have different views

Depending on the application of what you want changes how much timing you run.

If you are building a street car you will need to run a safe timing of close to 20 degrees/18psi due to standard fuels not always being consitant.I have had my skyline on the dyno many times and have found that running to much timing can be good but at times bad as well as i have got a bad batch of fuel.

When you go racing on c16 fuel etc you can run as much timing as you can as long as your engine isnt knocking.You are better off watching your knock sensors and checking timing on the dyno then on the street.Air temps of the motor make a big difference on the ability to make a motor run alot of timing too.i found by runing a larger cooler in a street car then what was recommended made me gain more power.

More timing will give you more torque but there are other aspects you will need to consider like aftermarket cams can run more timing then most standard cams.

I pefer to have a little bit more timing then more boost just because in my own view runing less boost and more timing in your motor to a safe limit and making more power and torque seems to be safer thats my view anyway but everyone has there own views and beliefs.

Everything varys and engines are all different

you will need to put it on a dyno and experiment.I am and it pays off

Edited February 23, 2006 by LNEMUP498HP

[paulr33]

boost does not make power, airflow does. increase airflow and you'll make more power. adding more boost "or pressure" simply takes away volume and adds more heat. which is the opposite of making more power. this is of course when you go out of the efficiency map of the turbocharger.

so it depends on your turbochargers compressor map, the map may give you that 24psi is still in effiency whereas on another turbocharger over 14psi is off the map and thus you just dial in more and more heat

[Sydneykid]

Maximum power at one rpm point is a USELESS number, how fast a car is depends on its average power over the used rpm range. Get your dyno graph and the 300+rwkw dyno graph and compare the average power, say 4,000 rpm to 7,500 rpm in 500 rpm increments. The faster car always has the higher average power.

cheers

[vspecll]

mmm.....

All very valid points,

Does anybody out there have compressor maps for GT2560-5 garret turbos ( there should be these are very popular lately)

I should have clarified PUMP FUEL 98.

BUT Does anybody out there want to contribute their figures and set up if they know them.

thanks guys for your input.

[Busky2k]

Visit turbobygarrett.com and download the catalog PDF for all your mapping needs.