[murph-54]

I am considering putting catless DP's on my car and have been told by someone that I would consider an expert that doing so could cause the coolant and/or oil temps to increase. His reasoning is that the DP's will allow the car to make more power which generates more heat. Has anyone that has installed catless DP's noticed any difference in their coolant or oil temps at the track?

[335iheLLraiseR]

well my car reaches operating temp a lot faster, but nothing excessive as like going from 250 to 300 degrees.

[Ironring Racing]

Exhaust mods simply reduce the back pressure on the exhaust stroke, which is physically seperated from the intake stroke. The DME is going to target the same stock boost, the turbo's will see the same discharge pressure (into the intake stroke), the same compression ratio, the same heat of compression.

Where you see increased power is really dyno power, not engine power. With a less restrictive exhaust, the exhaust gases exit the chamber easier, thus less parasitic losses on the engine having to push the gas out. This power is now available for the wheels, and thus you get better acceleration, i.e. better "dyno" power.

Same effect as putting lighter wheels on your car. Your car is now faster, but the engine is making the exact same power, exact same heat, just moving faster. On a dyno you would see faster acceleration and it interprets it as more power. In other words, you're just reducing the drivetrain losses, and more of the motor power goes to the wheels. If anything, with more power to the wheels the car will accelerate faster, you'll reach the target speed faster, and the engine will be under load for a shorter period of time, and you'll make less heat in the process.

The less restrictive your upstream intake tract (intake, FMIC) the lower the compression ratio on the turbos and the lower intake air temps. This will help lower the engine temps.

All things being equal, if you have or are thinking of a tune, more boost means more power means more heat. But if you're not tracking (road course) your car, and it has the an oil cooler, you should be fine on the street.

If you are tracking your car, you'll have to play it by feel. Depends on your track, your style, how hard you push, altitude, air temps, etc., but you may need to add additional cooling at some point.

[bulldog_yyc]

Originally Posted by Ironring Racing

Exhaust mods simply reduce the back pressure on the exhaust stroke, which is physically seperated from the intake stroke. The DME is going to target the same stock boost, the turbo's will see the same discharge pressure (into the intake stroke), the same compression ratio, the same heat of compression.

Where you see increased power is really dyno power, not engine power. With a less restrictive exhaust, the exhaust gases exit the chamber easier, thus less parasitic losses on the engine having to push the gas out. This power is now available for the wheels, and thus you get better acceleration, i.e. better "dyno" power.

Same effect as putting lighter wheels on your car. Your car is now faster, but the engine is making the exact same power, exact same heat, just moving faster. On a dyno you would see faster acceleration and it interprets it as more power. In other words, you're just reducing the drivetrain losses, and more of the motor power goes to the wheels. If anything, with more power to the wheels the car will accelerate faster, you'll reach the target speed faster, and the engine will be under load for a shorter period of time, and you'll make less heat in the process.

The less restrictive your upstream intake tract (intake, FMIC) the lower the compression ratio on the turbos and the lower intake air temps. This will help lower the engine temps.

All things being equal, if you have or are thinking of a tune, more boost means more power means more heat. But if you're not tracking (road course) your car, and it has the an oil cooler, you should be fine on the street.

If you are tracking your car, you'll have to play it by feel. Depends on your track, your style, how hard you push, altitude, air temps, etc., but you may need to add additional cooling at some point.

good post!

[murph-54]

Originally Posted by Ironring Racing

Exhaust mods simply reduce the back pressure on the exhaust stroke, which is physically seperated from the intake stroke. The DME is going to target the same stock boost, the turbo's will see the same discharge pressure (into the intake stroke), the same compression ratio, the same heat of compression.

Where you see increased power is really dyno power, not engine power. With a less restrictive exhaust, the exhaust gases exit the chamber easier, thus less parasitic losses on the engine having to push the gas out. This power is now available for the wheels, and thus you get better acceleration, i.e. better "dyno" power.

Same effect as putting lighter wheels on your car. Your car is now faster, but the engine is making the exact same power, exact same heat, just moving faster. On a dyno you would see faster acceleration and it interprets it as more power. In other words, you're just reducing the drivetrain losses, and more of the motor power goes to the wheels. If anything, with more power to the wheels the car will accelerate faster, you'll reach the target speed faster, and the engine will be under load for a shorter period of time, and you'll make less heat in the process.

The less restrictive your upstream intake tract (intake, FMIC) the lower the compression ratio on the turbos and the lower intake air temps. This will help lower the engine temps.

All things being equal, if you have or are thinking of a tune, more boost means more power means more heat. But if you're not tracking (road course) your car, and it has the an oil cooler, you should be fine on the street.

If you are tracking your car, you'll have to play it by feel. Depends on your track, your style, how hard you push, altitude, air temps, etc., but you may need to add additional cooling at some point.

Thanks for the info. I have tuned the car (PROcede) and track the car pretty hard 15-16 days a year. I also have a FMIC, BBK, modified suspension, after market oil cooler, LSD and track wheels and tires. I'm thinking of going to catless DP's as this will allow me to run more aggressive map on the PROcede with more boost and gain another 20 HP or so. However given that I am already running oil temps already at 280 - 290 after 15 minutes or so even though I have the VK oil cooler, I am concerned about any additional increases. Does anyone have any experience with putting catless DP's on a tracked and tuned car and the impact on oil or coolant temps?

[Kelvin1000]

It might actually help to go with a catless setup since the whole system will be less restricted and the Turbos will work easier. This car is no M3 though... those track sessions in the heat are no good!!!