Ace Header 4-2-1 CS400 Custom BRZEdit Tune Dyno Results
 

Just got my car back from local tuner. Car was bone stock in terms of engine mods before Ace Header CS400.

CS400 makes about 15kW and 20Nm from stock on 98ron ... and here are the dyno charts.

What's with those hand drawn looking loops in second pic? :/

I asked the same question to the tuner. I can't remember the exact answer but it was along the lines of dyno getting up to speed to match the speed of the car and sensitivity of the machine.

I found it quite odd too...

No offense, but this looks like a dyno curve drawn by a child instead of a printer..

Also imho not everything is that shiny with tune. I'd expect more gains with proper custom tune .. and shouldn't CS400 be THE torq-iest ace's header with least power gain at top rpm-s? Yet it looks like more gains on top, then in middle. Seems that opensource tune with full gains for what these headers are capable off on par with DT tunes is still to happen.

That dyno graph has some serious issues. Not to mention all the dips in power. Either they have something going on with the dyno or something with the tune id look into it.

There is either something seriously wrong with either the tune, or the dyno, or maybe both.

... or the operator doesn't know what he is doing, either with the laptop or the dyno :)

+1

Dem roller coaster gainz!

I'll get them to have a look into it.

I'm no expert on this stuff. Just posting a dyno chart since there's none around for the CS400.

Will let you guys know what I come back with.

Graph isn't useful without a comparison to the same stock car with a tune anyway. Stock tune on 98ron is so temperamental to the point that using it as a comparison is a waste of time.

im actually quite surprised at the comments in this thread, its obvious its run on an ultra accurate hub dyno not a inertia masked roller dyno.

We changed tuning from a roller dyno for this precise reason (20 years of tuning experience showed we needed something different for product and race engine development) the larger the roller the more inertia it carries... the more inertia it carries the less accurately it actually records the natural tendencies of an engine (if you think a nice smooth curve is natural on a small displacement NA engine your sorely mistaken, run up a motorbike and you will be mortified). A dyno jet (mainline and Dyno dynamics rollers) smooths out the curve so much that for tuning small na engines properly its often quite useless. We could have bought 3 roller dynos for the price of our hub dyno but the tuning accuracy it afford us is not available in another package.

I can, on a small output engine like the fa20 turn on the lights mid run and get a dip from the alternator draw mid run, i can also pick very minute timing changes mid way through a curve, something we could never do on a roller dyno. This purple run also shows a dip from the cooling fans engaging which was done to check mixture variance under voltage change.

This same car run up on a dyno dynamics, mainline or dynojet will have table flat torque and pretty much a flat 45 degree power pull with a faint roll off up top.

The purple loop that seems to be perplexing everyone is the result of loading the car fully at 1500 in 5th gear and starting a heavy ramp rate pull which accentuates the peaks and troughs, such a small output engine will always struggle to pull cleanly from such low rpm (try it on the road starting off from the lights in 5th gear). We do a LOT of circuit cars so we comprehensively tune every part of the map, this was just one run in a larger process. Normally we don't generally provide this heavy load run to the customer but Harry is quite the enthusiast so we gave him more than just the before and after plots. Starting at 2000rpm or doing a soft start ramp stops this looping behaviour as seen in the other plots..

i hope this gives a bit more insight into the dyno plots and the behaviour differences between hub and roller.

If anyone would like to chat further im happy to answer any questions on info@chequeredtuning.com

True but TBH the factory tune is stable if you ensure both cams are active, ive seen a lot of cars at dyno days run up (straight after start up) and pull low numbers then after idling a few seconds going on to pull constant numbers. (ive attached an example Avo turbo kit with supplied tune before we fixed it)