S2000 (F20c): 50 trim Turbo - Pump gas Dyno Tune

[Spent]

This car belongs to Mark from Boiling Springs. He came to us today for a tune. His car was previously tuned by another shop, but he had several idle and drive ability issues. He wanted to clear up those problems, as well as retune on more boost for a little more power.

Here's the setup:
F20c
InlinePro Manifold
Tial 38mm wastegate
780cc RC injectors
AEM FPR (base FP 50 psi)
Custom down pipe and dump tube
Custom intercooler piping
Precision Intercooler
Cometic 2mm headgasket (lowers static CR to approx 9.8:1)
eBay 50 trim T3/T4 turbo

Here is the tune from today. It's only on the wastegate, which is fluctuating between 7.1 and 7.3 psi.

http://i672.photobucket.com/albums/vv89/tdcweb/eBlogger/mark71psi.jpg




http://i672.photobucket.com/albums/vv89/tdcweb/eBlogger/DSC_0011.jpg

http://i672.photobucket.com/albums/vv89/tdcweb/eBlogger/DSC_0013.jpg

http://i672.photobucket.com/albums/vv89/tdcweb/eBlogger/DSC_0015.jpg

And, for the video:

YouTube - Mark Youtube.wmv (http://www.youtube.com/watch?v=w5hnPN7Iv18)

[Spent]

This particular setups spool ridiculously quick, as it should considering it's a 50 trim. The owner wanted a reliable daily driven and "cheap to build" setup and this encompasses all of that.

The following is for those who study our work and may be looking at this setup from an analytical point of view and have taken notice at the slight dip in power pass 6100k rpms.

In this particular case and considering the characteristics of a typical log manifold on a high revving motor, it's due to the log manifold restricting this setup . A common and noticeable side affect of log manifolds is cylinder cross contamination. This is more evident by the fact that injectors values are lesser at 9k rpms than at 6k rpms. Keep in mind that cylinder cross contamination has several different effects on a motor depending on the exhaust manifold design. In this particular case, unburnt fuel in the exhaust manifold reverts back into another cylinder which amounts to telling the ECU to inject less fuel to maintain proper a/f ratios. Hence lesser injector values at 9k than at 6k rpms. Generally speaking, you can say it's choking the motor since some of the HOT exhaust gases have nowhere else to go but back into the motor depending on the level of cross contamination... Add the turbulance of all the exhaust gases joining together at such a short distance from the motor and this adds to the issue.

This depends on the amount of boost as well. At some boost levels, it's easy to spot and at other boost levels, you would never know it's taking place although it actually is. You can still have cylinder cross contamination on a single scroll side-mount turbo setup but it generally has a different affect. Generally the VE of the motor is still affected but not nearly at the same extent. Usually side-mount setups don't have exhaust gases reverting into another cylinder. Instead, the exhaust pulses interfere with each other but to a lesser degree because of the greater distance from the exhaust manifold and the fact that each cylinder has it's own dedicated path for a well enough length instead of converging violently like in a log setup. Solution, divided housing manifold WITH DUAL WASTEGATES and this effect is eliminated. Unfortunately, some of these manifolds can cost more than an entire setup which defeats the customers goals and at the end, the customers goals is what's most important.

Back on topic.

Mark, like many of the standalone ECU setups (such as AEM , Motec, Haltech, PowerFC, etc..) we've tuned, come to us mainly because of drive-ability issues. A lot of people don't realize this but tuning for power is actually the most straight forward aspect of tuning. On the other hand, tuning for drive-ability and partial throttle is probably the most time consuming depending on the EMS used.