Dyno Plot Library

Wynn Suebhongsang

Sun, 1 Mar 2009 15:00:24 -0500

Wynn drove from Nashville, TN to Atlanta, GA to come and see us during our three day tuning event. There had been a cancellation so Wynn took the available slot and made the drive through less than wonderful weather conditions to be tuned. His Honda S2000 had previously been tuned with a GReddy e-Manage Ultimate by another shop but he wanted to see if we could better those numbers. We did some baseline runs with and without his previous tune and found that it had been tuned lean and actually lost power at high RPM. We flushed the e-Manage and updated his wiring harness and started our tuning work. The fuel mixture was optimised for his J’s racing setup and since he had a test pipe VTEC engagement was lowered resulting in a large increase in midrange torque. Peak power was increased a little but the biggest improvement in that area was the elimination of the lean mixture that is common with extensive intake and exhaust modifications. Wynn contacted Jeremy, the organiser of the event while on his way home very pleased with improvements in torque and throttle response. We’re glad that you made the drive and that we could exceed your expectations!

Ryan Odea

Sun, 1 Mar 2009 11:00:22 -0500

Ryan returned with his F22C powered Toyota Celica for a retune, but this time there was something very different. Ryan had converted the engine from the stock single throttle body based intake to individual throttle bodies (ITBs). In anticipation of the extra power, 440 cc fuel injectors had been installed replacing the stock injectors. With ITBs, the first task is to switch the engine management approach from speed density to alpha-n as the density sensor is very ineffective. Even a small throttle opening angle results in near atmospheric conditions in the intake tract hence the density sensor no longer relates linearly to cylinder air consumption. Another measurement approach must be taken. OEM ITB setups, such as those in the BMW M3 use a single mass airflow sensor in the entry pipe to a chamber which houses the throttle bodies however this is not possible with Ryan’s setup as they are individually open to the atmosphere. The only approach that can be taken is to use the throttle angle as an indication of flow. The additional airflow provided by the ITBs results in a significant improvement in power output, up from approximately 240 whp to nearly 270 whp. With the original intake manifold, VTEC had been lowered to 4000 rpm, but with the ITBs 5000 rpm was the most efficient transition point. The induction sound now produced is phenomenal, making this unique F22C application that much more special.

Louis Debennedictis

Sun, 1 Mar 2009 09:00:26 -0500

A few days after we had tuned Louis’ car last year his HKS exhaust arrived and thus threw his old tuning off some so when we came down this time he jumped in and got it retuned. His new exhaust reduced back pressure and hence enabled us to get some more power out of the high lift VTEC cam lobes. The switchover point was dropped further down the RPM range and several lbft of torque was added almost uniformly from 6000 rpm upwards. One added benefit of the HKS setup is that peak power is moved down a few hundred rpm which helps reduce the need to bounce off the rev limter when extracting the most from the F22C. Louis’ S had also started exhibiting a strange random misfire. Given that we only had a short time slot purely for tuning we investigated the quick stuff like plugs, sensors etc. but nothing obvious was wrong. The engine is performing perfectly leaving the likelihood of an electrical issue such as a poor ground of defective voltage regulator. Stay in touch Louis and let us know what you find.

Devin Penny

Sat, 28 Feb 2009 13:00:57 -0500

This was the first time we had met Devin and his S2000. A number of upgrades had been performed to his S, such as exhaust headers, the exhaust itself etc. These modifications usually result in a lean mixture condition and this one was no different. AFRs of 15:1 were found around the VTEC engagement point which were dutifully fix by tuning with an e-Manage Ultimate. VTEC was dropped to 4000 rpm and the fuel mixture optimised to the ideal air to fuel ratios for the F20C. Ignition timing was adjusted to squeeze the most out of the fuel mixture resulting in some pretty nice gains, especially where the stock ECU rolls off at high RPM. Devin arrived early and since we were running ahead of schedule we tried a little experiment. The later model S2000s have a divider in the air box lid that is not present on earlier models. Since OEMs don’t do anything unless they have a pretty good reason, we clipped the new cover onto the old air box and did another pull. We were pleasantly surprised to find that it resulted in an increase of 2 horsepower, taking this 238 whp S2000 up to 240 whp! Unfortunately Devin had to give it back to Jeremy, but I’m sure that in the light of this information, airbox lids may start changing hands on e-Bay ...

Deiter Haemmerich

Sat, 28 Feb 2009 11:00:57 -0500

Deiter is a track junky. Unfortunately S2000 catalytic convertors were not designed to withstand the repeated abuse that full throttle straights over and over again can produce. After replacing the catalyst too many times to even be able to remember, Deiter took the opportunity of our visit to replace the catalyst with a race pipe so this would never happen again. The race pipe enables significantly more flow from low rpm upwards due to a reduction in exhaust back pressure enabling us to lower VTEC down to 4000 rpm. With a little bit of careful tuning you can produce an almost flat torque curve from about 2500 rpm all the way to the 8000 rpm redline. The normal VTEC engagement surge is gone, but what you get is a smooth delivery, perfect for accelerating out of corners due to the linear relationship we tuned in between the throttle and supplied torque, regardless of RPM. We hope Deiter has a great year and that he will continue to help us evolve our tuning skills to suit the needs of the track.

Janssen Pimentel

Sat, 28 Feb 2009 09:00:58 -0500

Check Engine Lights (CELs) are rarely a good thing. Last time we saw Janssen he had one. His Honda S2000 had a lumpy idle and I knew that sound, and it wasn’t good. The DTC confirmed that cylinder #4 was not happy. We were unable to tune his car at that time for fear of increased damage. Since then Janssen took his S to the dealer who replaced the cylinder head and now his car came back from the dead, stronger than ever, in fact the most powerful unassisted S2000 to date! We did the Double VTEC trick on this one too, producing a nice flat torque plateau before the high cam became fully efficient above 5500 rpm ending with a jaw dropping 259 whp! Jeremy had a theory that the engines that get ‘beaten on’ would produce the most power. The theory had shown some merit when Minsoo’s engine went from under dog to top dog after 6 months of being driven hard. Janssen’s, with 70,000+ miles on the clock of hard driving, topped them all! I’m so glad that Janssen’s story had a happy ending after the circumstances of the last event. The graph shows the tuning that we did 18 months prior against the new results - 10 hp and 10 lbft increase over the last tune. I have no idea how we are going to top this in the future, but we’ll try!

Jeremy Dibble

Fri, 27 Feb 2009 15:00:58 -0500

Jeremy, the host of this Atlanta event had recently traded his S2000 for a new model and had been driving using one of our pre-tuned units. We did a number of baselines without the e-Manage, and then with the pre-tuned e-Manage and finally a custom tuned was done to see what the differences would be. The pre-tuned did pretty well, coming within a few lbft of the custom tune, however we did some fun tricks in the mid range with the custom tune ... Double VTEC. We found that VTEC helped produce some good gains down low, but then in the midrange it actually dipped down below where the low cam power had been ... the solution, switch VTEC on, then off, and then back on again, i.e. use VTEC where it helps and don’t where it doesn’t. The e-Manage has full control over the VTEC solenoid so the stock ECU has no clue of the games that we are playing to get the most out of the engine. The end result was more torque in the 4000 rpm area. We also did some different approaches to the part throttle modifications that Jeremy prefers, customising this tune specifically for his driving tastes. Thanks for organising this. It is always a pleasure!

Tut Brown

Fri, 27 Feb 2009 13:00:59 -0500

The first day of tuning just kept getting better and better as Tut rolled in with his supercharged S2000. Tut had attended our last event but his differential packed in half way through tuning. This time it had been replaced and was ready for all that we could throw at it. Tut’s VAFC had been replaced by an e-Manage Ultimate driving RC Engineering 550cc fuel injectors. Injector pulse widths were trimmed for the larger than stock fuel injectors using the dyno’s ability to hold fixed rpms, making modifications of RPM/Load based tables a breeze. Once the part throttle tuning was completed the mixture was then tuned for the boost areas. The engine was left to cool for a while and at that point, with no timing modifications, the wheel hubs we producing some 290 whp. If you look at the chart you’ll see that our final numbers were 342 whp, so the additional 52 whp was made by adjustments to the ignition timing, something that is impossible for the VAFC to accomplish. VTEC was dropped down to about 4000 rpm, taking advantage of the increased air supply from the centrifugal supercharger and careful adjustments near redline enabled the power to just keep going and going, getting the most out of the 7 PSIg pulley. The 200 lbft barrier was broken at 6500 rpm and continued until the limiter kicked in which is pretty good for a S2000. Another happy owner!

Tony Bell

Fri, 27 Feb 2009 11:00:59 -0500

Tony is the owner of Vader II and last time we were here Vader was having some breathing difficulties (stands to reason really). This time Vader had been equipped with a new high flow catalytic convertor and was instantly breathing a lot better. Peak power was easily attained and the cat flows so well that we were able to drop VTEC down much much lower, a benefit that is usually reserved for those with a test pipe installed. The lowering of VTEC gives a nice midrange punch that we set to enable at large throttle angles as so not to damage fuel economy and smoothness in daily driving. The increased exhaust flow enabled us to adjust the ignition timing and fuel such that the power was still increasing all the way to redline. I’m so glad that we were able to bring out the best in this engine and its amazing HKS exhaust this time around. If Tony is happy then we are too. May the force (measured in lbft) be with you!

Christy Dibble

Fri, 27 Feb 2009 09:00:01 -0500

We’ve been invited to Atlanta, GA by Jeremy and his wife Christy to do three days of tuning. We loaded up the truck and hit the road for the two day journey away from the snow of New Hampshire, or so we though, to the sun of Georgia, or so we thought. It turns out NH was having a mini heat wave and GA was having rain and snow! Oh well, but the people and cars are great! Jeremy hosts the local Honda S2000 group, but our first car of the event was an Infiniti G35 driven by the ‘screamingly skilful’ Christy. The car has some Stillen goodies on board and an e-Manage Ultimate to get the best out of them. Aided by another S2000 owner, Glenn, we set about tuning this great sounding machine. We were able to produce a net peak increase of about 14 whp and 10 lbft torque almost across the entire RPM range after finding the idea air fuel ratio and ignition timing for the 3.5 litre V6 ‘Rev-up’ motor. As always, we did our part throttle tuning which is where the e-Manage assists greatly, enabling a much more fluid and responsive driving experience. There’s and autocross on Sunday... I wonder if Christy is driving?