SRT Shoutbacks: fans' questions answered by the engineers themselves.
SRT engineers are among the most customer-responsive in the industry. Post your question on our Facebook page or tweet it using the #SRTshoutbacks hashtag, and we'll do our best to get your question answered. Unfortunately, we are not able to answer questions regarding production figures or future products.
Mike writes: Can I run SRT's new Pennzoil 0W-40 in my Neon SRT4?
Kraig designs engines and engine parts as the lead SRT powertrain engineer.
The answer to that is yes: Pennzoil 0W-40 is a quality synthetic oil. If you look at the recommended engine oil for the SRT4, it says to use a quality synthetic. The new Pennzoil synthetic has a 250 ppm moly in it, and will adjust its viscosity to the temperature of the engine.
John writes: How can I tell if I have the Stage 1 ECU on a Neon SRT4? I looked at the ECU and it's stock, but I suspect that it's been re-flashed.
Erich worked on the SRT4 before it was even a PVO project. Now, he serves as the Vehicle Integration Responsible manager for the SRT Viper.
Even though it's against protocol, it isn't possible for us to control people flashing their personal cars and then reselling them. The only way to be able to tell for sure is to put a stock ECU in the car, and then run it on a chassis dyno back to back.
Scott writes: Can you find out if the 2012 Grand Cherokee SRT8 and the 2011+ non-SRT Grand Cherokees or Durangos use the same spindles?
Marco is the vehicle dynamics engineer responsible for Grand Cherokee SRT8. When he's not tuning Grand Cherokee SRT8s on the track, he autocrosses his Crossfire.
The front knuckles are a common part. However, the rear knuckles are sourced from the Durango.
Our first mule had the standard Grand Cherokee rear knuckles in it, but it just didn't meet our subjective criteria for handling. When I put the Durango rear knuckles in, I got the response I was looking for. We basically dialed out the rear axle understeer by fitting Durango rear knuckles instead.
The Durango knuckle has a different mounting point for the lower link, which changes your toe curve, which brings in the zero-roll-steer, enabling more responsiveness.
We use the Durango R/T swaybar front and rear. However, the swaybar links are unique to SRT, because as you lower your vehicle, you don't want to preload the swaybar on the mounts. To avoid a preloading condition of the swaybar on the mounts, we had to develop unique shorter links for the swaybar.
John writes: I am confused about the new GTS-R. I watched the video that was just posted of it on the track, and I paused the video during an inside the car shot. There is no shifter. Is the GTS-R push button shift? When the car shifts, it looks like the driver is pressing something behind the steering wheel.
The Viper GTS-R uses a custom, purpose-built, rear-mounted Xtrac transaxle that is actuated by paddle shifters. This transaxle is not related to the street car, which uses a normal transmission.