||Project Cars, Dyno Testing, Engine Computers, Performance Parts, TSX
||March 18, 2005 11:24
||April 26, 2005 14:17
Hondata ECU Flash for Acura TSX
Finding More Power for the Project TSXBefore even taking delivery of TOV's project TSX, one of the things we knew we'd have to address at some point was the K24's power. From the factory, the TSX is quite a satisfying piece of kit, but if you're accustomed to driving relatively powerful vehicles, in stock configuration the TSX's K24 falls a little short. It's refined, smooth, and as torquey as the day is long, but to really appeal to driving enthusiasts, it definitely needs some more spice, particularly in the upper third of the rev band. Knowing that the TSX's K24 motor shares much of its design with the K20 (found in the RSX Type S and Integra Type R), we figured that it wouldn't be long before the gurus at Hondata would liberate copious amounts of otherwise untapped power from the K24. Without having that sense of confidence, I might have waited for something else to come along, but as you will soon see, things are coming along nicely in terms of TSX power-adders.
Now to be honest, I was also hopeful that the development of this ECU reflash would have been accelerated by the fact that the RSX and Civic Si's K20s had already been fully cracked, but it turns out the TSX's K24 uses an entirely different engine computer than the K20 and thus required a fully involved cycle of reverse engineering sleuthery. Back in 2003, Doug Macmillan warned me it could be 18 months or more. Well, as it turns out, they came in ahead of that initial estimate, but we're still in the beginning stages of K24 development.
Knowing initially that major bolt-on power gains were not to be had on the TSX for some time, we've kept the mods simple under the hood on our Project TSX. In fact, to this point the only thing we've touched underhood has involved the intake tract. The first item we installed and tested on our project car was AEM's Short Ram System along with Hondata's intake manifold heatshield gasket. Following that, we were ready to stiffen up the suspension, so we fitted Acura's full A-Spec package, and shortly thereafter we found we could no longer live with the OEM tires and we convinced Michelin to allow us to test a set of their Pilot Sport 2 tires (that article is forthcoming, but I can tell you the tires are FANTASTIC). Now we have a few more chassis items we wish to address, but since we knew the first fruits of Hondata's TSX development were imminent, we're going to temporarily shift our focus back to a few power-adding items again.
In speaking with Hondata over the past few months, we learned that the development work on the first version of the TSX reflash to be released was focused on K24s already equipped with some sort of intake system and an aftermarket header. Armed with this knowledge, we e-mailed our friends at DC Sports and Comptech and both vendors agreed to supply us with their respective exhaust headers, so eventually we will have dyno figures for all of these items on the TSX. DC Sports had their headers in stock and shipped a set to us immediately. Comptech is currently out of stock but has plans to ship their headers to us (and we're hoping an intake system as well) within a week or two.
Hondata's development TSX is a 6-speed model that is currently configured with a Comptech Icebox Intake and Comptech's 4-2-1 stainless headers. As such, the dyno figures shown on Hondata's product page for the ECU flash reflect the specific results for that configuration. The figures you will see here show the results on an AEM/DC Sports configuration, and to add a bit of further confusion, the dyno we use here is a Dynojet, vs the Dynapack that Hondata uses for their development work. The Dynapack is a chassis dyno that bolts directly to the hubs of the vehicle in place of the drive wheels. Removing this rotating mass from the system results in higher net readings from the Dynapack, usually to the tune of about 10hp or so.
InstallationLater we will post photos detailing how to uninstall your stock ECU and immobilizer, so you may ship them (along with one of your keys) to Hondata's HQ in Torrance. For the time being I can tell you that it's not a majorly difficult operation, but plan about 30-45 minutes for a full deinstall/install cycle.
Dyno ResultsFor the dyno plots in this article, we already have a DC Sports header installed (part of another update soon to be published), along with the existing AEM SRS and Hondata intake manifold heatshield gasket. All else remains stock. For today's dyno test, we tested the car first with the Hondata tuned ECU. Once we established stable output numbers, we shut the car off and switched out the ECU with a stock TSX ECU and repeated the dyno runs. The results are shown below.
The table that follows shows the actual gains that you would realize during a full throttle run through the gears.
|Overall Average ||7.52||3.38|
As you can see, Hondata's strategy of lowering the VTEC engagement RPM to 5000 (from 6000) paid off handsomely. They also added a bit of timing and made some cam timing adjustments in several spots, and you can see that these adjustments paid off quite nicely as well. Finally, the stock rev limiter was raised from 7300 RPM to 7600 RPM, which is useful because with the intake and header the car is still making useful power at the stock 7300 rpm limiter. For this test, you can see that the peak power is barely increased, but look at the huge improvement in torque and power from 5000-6800 rpms. That is something that can definitely be felt on the street. There is also a modest boost in torque on the lower end of the rev range, and this can also be felt on the street, but not quite to the extent of the newfound upper-midrange zestiness.
On the street
On the street the advantage of the Hondata flash can be felt the first time you swing the tach needle past 5000 RPM. It's not so much what you feel, but rather what you don't feel. By this, I mean the changeover of cam lift profiles at the stock 6000 RPM setting. By moving the VTEC engagement point down to 5000 RPM, there's no discernable transition point because instead of nosediving after 5000RPMs, the torque holds steady and the horsepower continues grow until it peaks at around 6800 RPM. Another big advantage of this is that the uptake following an upshift is much smoother and you can feel the additional power, as the stock shiftpoints really bring to light the stock car's hole in torque from 5000-6000 RPM. Based upon the actual ratios measured on the dynojet, we calculated the following data based upon rev limiters of 7300 and 7600 rpm:
|NOTE: RPM figures are rounded to nearest 50 RPM|
Please be sure to visit Hondata's product page for the TSX ECU Reflash to learn more about how to get it for your TSX.
Thanks once again to Dynolab of Marietta, GA for providing us with the services of their dynojet.