chip tuning

[JP]

I want to put water methanol injection.

Is the number one reason for bend rods on a turbo'd car. Seen it time and time again ever so slight a bend in the rods enough to cause misfire under load, not big enough to stop it from running.

As for chips I'm in the process of trying out some different chips on my motor and documenting them as I go along. I'm currently awaiting the last two sets to complete the final road testing side of things. The most interesting thing I've noted is that the chip differences are down to boost delivery and how well they fuel after 4750rpm when the MAF tops out and can no longer adjust fueling.

The good chips will pull through the 5000rpm the bad chips won't. All of them are reading safe EGT's and AFR's.

As a random test running a boost chip from a 'chipped' chip set with a standard fuel and ignition chip runs perfectly fine EGT's and AFR's as the ECU self adjusts the fueling and ignition s long as the MAF is within it's 5v operating range. Once this is exceeded all that happens is the ECU goes into safe mode and backs of timing to keep things in check resulting in a flatspot over 4750rpm. At no point datalogging all the parameters would I say that AFR's or EGT's are considered dangerous.

This in turn means that if you where to refit the MAF in a larger housing to lower the voltage range bringing it back under 5v in the upper rev range and increase the injector size to compensate as the lower MAF voltage will result in a reduced duty cycle for the injectors. The standard fuel and ignition map is capable of supporting the boost increase throughout the rev range. Which funnily enough is exactly what the Jap boys do.

[driftin jo]

Is the number one reason for bend rods on a turbo'd car. Seen it time and time again ever so slight a bend in the rods enough to cause misfire under load, not big enough to stop it from running.

As for chips I'm in the process of trying out some different chips on my motor and documenting them as I go along. I'm currently awaiting the last two sets to complete the final road testing side of things. The most interesting thing I've noted is that the chip differences are down to boost delivery and how well they fuel after 4750rpm when the MAF tops out and can no longer adjust fueling.

The good chips will pull through the 5000rpm the bad chips won't. All of them are reading safe EGT's and AFR's.

As a random test running a boost chip from a 'chipped' chip set with a standard fuel and ignition chip runs perfectly fine EGT's and AFR's as the ECU self adjusts the fueling and ignition s long as the MAF is within it's 5v operating range. Once this is exceeded all that happens is the ECU goes into safe mode and backs of timing to keep things in check resulting in a flatspot over 4750rpm. At no point datalogging all the parameters would I say that AFR's or EGT's are considered dangerous.

This in turn means that if you where to refit the MAF in a larger housing to lower the voltage range bringing it back under 5v in the upper rev range and increase the injector size to compensate as the lower MAF voltage will result in a reduced duty cycle for the injectors. The standard fuel and ignition map is capable of supporting the boost increase throughout the rev range. Which funnily enough is exactly what the Jap boys do.

Your comments on the MAF topping out seem a little strange as many tuners have used bigger turbo's and injectors to pull over 400hp from the standard setup before reaching the limit of the MAF.

[JP]

See below a screenshot of a recently overlaid datalogging plot of two different cam configurations on a 2nd gear WOT pull from 1900rpm to the redline.



See the user input line at the bottom of the screen shot this reflects the MAF voltage at exactly 4752rpm it hits 5v on WOT.

Now this doesn't mean that the standard MAF can't support 400 or 500hp with bigger turbo and injectors. What it means is that the MAF is no longer giving a useable data feed for the ECU to self calibrate to measured airflow.

This is where the ability of the tuner comes into play as there is no longer any compensation it is purely down to the ignition and fuel map written by the tuner.

This is one of the things I am currently reporting on in my thread as it shows which tuners have taken a lot of effort to write a good map and which ones have just cranked up the boost.

[porkkis]

Std maf is maxed out at around 440fwhp. The output does exceed 5V.

Basically the tune can not be done right when maf is maxed as motronic does internal calculation of fuel required for given air mass. This can be compensated by requesting richer mixture at max load (scaled of course) but that brings along other problems.