waxking1

I have a Renntech Throttle Body and some Renntech Headers I've had for about a year and never installed(2005 E55). I'm going to install them soon and would like to know if it is necessary to reprogram the ECU also. I already have the RT pulley with RT programming on the car. Will it hurt anything to drive it for a while without reprogramming again? I plan on having the ECU remapped at some time but it is just not convenient at this time.

BenzoBoi

I think you will be okay...but you won't be able to take full advantage of the headers and the TB without that tune...

I'm only a n00b so I'm sure someone can correct me if I'm wrong...

Oxygen

You will ABSOLUTELY need a new ECU program with the larger throttle body and headers. The car will be running very lean, feel very fast but it will not be safe for any extended period of time.

waxking1

Thanks for the info. The problem is that the car will only be in the shop a day or two and I will have to pick it up. This isn't enough time to send my ECU to Renntech. Its about 10 miles from my house to the shop so I need to get the car back home and then send off the ECU. I assume this would be OK?

James@ACG

Talk to your shop and see if you could leave it there for an extra day.

This is what we doing for one of our customer who is install Kleemann headers, drop the car off, we'll rack it today, even tho we won't start until tomorrow, pull the ecu and overnight it today. Then just have RENNtech overnight am delivery for you and your shop will have the reprogrammed ECU by 8-10am in the morning.

Hope this helps.

waxking1

Seems like I see conflicting info on this. In another thread someone is running a larger pulley than the Renntech and also an 80mm throttlebody with seemingly no ill effects, so why would I need a tune just to drive the car 10 miles?

jangy

You can add a TB and headers without any adjustment in tune and your car will be fine. I wish i could get this thing to run lean. You already have an RT tune, so your pulley should be performing. Either way, even if not optimal your car will be fine to drive forever much less 10 miles. I'm still waiting to see some data from a new RennTech tune that shows TQ management control.

jangy

So RennTech just has a tweak for Kleeman headers or are you sending in data? Also, I thought RennTech was able to send files back and forth with its vendors to avoid the ECU shipping. A spare ECU is looking better and better.

rarfinancial

I know have three ECU's Jangy is right.. A spare ECU is a must..

jangy

3? Wait, what happened? Give me a link, if you posted it. I knew about the OEM one, then a new one that MHP was to flash. Let me guess, got the 3rd to retire the original? How long does it take and how involved is swapping it out?

rarfinancial

The Renntech ECU, which is still good, the new stock ECU, that is in my car now will be sent to Andy in the morning and the noncoded ECU, that will get coded this coming week and stay stock. The R&R is about 10 minutes tops..

waxking1

Thanks guys,
I thought it would be fine but I wanted to be 100 percent sure. I had some conflicting info above.