We have now completed the installation and idle/part-throttle PCM calibration for the addition of Stainless Works long tube headers on our 2004 CTS-V R&D vehicle. The 2 1/2" stainless steel lead pipes were engineered in-house to cleanly mate to the existing unmodified Corsa exhaust system and feature both post-cat stainless steel rear o2 sensor bungs and 3" metal-matrix high flow catalytic converters to retain emission compliance in appearance and function.
Below is our impression of the system described after 110 miles of real-world driving during the PCM calibration process for both in-town traffic and open expressway cruising.
- Overall, very easy to install.
- #7 tube contacts the bellhousing requiring slight relieving of the bellhousing and the header tube for proper fitment. A phone call and photos sent to SW is all it took for them to address/correct the issue for future production.
- O.E. stainless steel header gaskets may be re-used, as they are the correct type for this header flange.
- Header mounting flanges are a VERY thick 3/8" and they do NOT leak in the least.
- O.E. flange bolts had to be cut down slightly to keep from bottoming out in head due the header mounting flange being thinner than the bulky O.E. iron manifold flange. New mounting bolts will be included in production kits for easier installation.
- O.E. o2 harnesses are of adequate length to plug right in on both sides.
- Plenty of clearance between header tubes and other areas of car (other than what has already been described) for both sides.
- Nice subdued rumble at idle outside and the type of exhaust note you would expect from a Caddy like this.
- No increased noise in the inside of the cabin other than what you would normally hear with the addition of the Corsa system when mated to stock iron manifolds and cats.
- Absolutely NO interior drone of ANY
kind, at ANY
RPM in the passenger cabin at part-throttle, mid-throttle or cruising...period. In fact, we were hard pressed to really notice a difference in interior noise other than what you would expect from the installation of a Corsa system mated to stock manifolds and cats.
- A very nice exhaust note/sing at WOT that is by far un-obtrusive both inside and outside of the car and it makes the kind of sound that doesn't attract the police, but clearly lets others know that the car is NOT stock.
All in all, we are VERY pleased with them thus far in both fitment and function and they seem to really compliment the Corsa system VERY well in all areas we looked at. We're very conservative when it comes to exhaust sound and loudness and often choose to lean toward the quiet side when we build a car here, so we we're pleasantly surprised and pleased with what we heard after this complete system was installed.
In a nutshell...the sound of this system is exactly what one would want for a car of this calibur and stature- Not too soft...not too loud.....just very muscular.
We have spent the better portion of these last few weeks developing a chassis dyno derived DTE Stage III performance upgrade package utilizing a cold air induction kit w/ an open element high flow air filter, high performance long tube headers/high flow cat. combination and a Corsa high performance exhaust system. Our custom PCM calibration which is used in tandem with these components, is written in-house using engine operating data obtained from the chassis dyno and from extensively driving the car in real-world conditions that the average customer may encounter from day to day. This calibration was completed using 93 octane pump fuel and the testing/engineering was just finalized today.
Currently it's available for the 2004-'05 model year vehicles with M/T and Fed. emission regulations at this time. This third performance upgrade package is specifically written for a vehicle that is equipped with a Corsa exhaust system, a cold air open-element airbox (such as LPE or More) and long tube headers backed by 3" high flow catalytic converters. 2005 model year upgrades coming soon within 6 weeks of this post.
As always, the drivability and power provided by this upgrade can be felt all over the powerband, cruising and at idle speeds. Fuel mileage will increase approx. 2 MPG over stock as well. We immediately noticed the increased torque output this combination produced making the car A LOT funner to drive over it's entire RPM band due to the increased power under the curve as compared to stock. The Corsa Performance exhaust system REALLY performed well in this combination in both desirable power output and sound levels inside/outside of the car.
Below are some figures we've documented from those tests and all subsequent dyno pulls were finalized on the same day, by myself personally, with the engine temps within 3* either way of the run preceding it. Original baseline power output remained the same as always for comparison accuracy. All control conditions varied by about 1% +/- throughout the testing session. Three pulls were made for each respective change for accuracy and the highest of the three was recorded.
This entire PCM calibration was written operating the vehicle in actual normal operating conditions that would commonly be found in every day, go to work/in-town type driving.
Dyno Cell and Vehicle Control Conditions:
Ambient temp- 42.4*
Absolute Barometric Pressure- 29.70 in./Hg
Vapor pressure- .051 in./Hg.
Rear Tire Rollout Ratio- 48.99 RPM/MPH
SAE Correction Factor- .94
Rear Tire Pressure- 33 psi
Engine/drivetrain temp.- 191*
Vehicle Mileage- 9210.0
340.6 RWHP/338.6 RWTQ
DTE Stage III Performance Upgrade Package w/ Corsa exhaust, open element cold air kit and SW long tube headers w/ matching 3" high flow cats:
375.0 RWHP/375.2 RWTQ
- CAGS deleted electronically. (removes function AND turns off annoying dash light all at once)
- Quicker wide open throttle activation
- Reduced engine operating temperature range from O.E. Now 195*-205* (O.E. 215*-233*)
- No A/C drag when WOT is selected and A/C is on. (You now don't have to turn off the A/C to get maximum power at WOT)
- Idle quality smoother
- ZERO detonation
- Accurate fuel and spark curves
- Emission compliant (Fed. only at this time)
- Compatible with 91 or 93 octane fuels
- Annoying "popping" sound from exhaust eliminated on decel and during shifts
- +2 MPG increase with highway cruising
- No speed limiter
- Corsa Performance stainless steel exhaust system
- SW/DTE long tube header set w/ 3" metal-matrix high flow cats
- 35 RWHP/37 RWTQ gain over stock
We are finalizing the production of the lead-pipes at this time and one can purchase this header upgrade set from DTE complete with the stainless steel long-tube headers, stainless steel lead-pipes, 3" metal-matrix high flow catalytic converters and any/all installation hardware with included instructions. Final costs have not been completely configured as of 2/05, but the target is to keep the entire kit under $1000-$1100. We will post those figures shortly. We should have the first sets ready for shipment within a 6 week time frame. If they become available any sooner, we'll post that as well.
Orders can be placed by calling the office at (260)407-5455 anytime during regular business hours and if you have a specific questions about this, or anything else, please contact me directly at ext. 11. Thank you gents and happy motoring.
Phil Rickard, President
Dynotech Engineering, Inc.