Quote:
Originally Posted by VMZ432
I tried that. Does exactly what you say, it makes the car take longer to get to normal levels of heat. But does not reduce the maximum oil temps appreciably on the track. I think I will switch back actually, because when I take the Z4 on the street it's because I want to enjoy it, and waiting nearly 10 minutes for it to heat up really annoys me. Often the trip I'm making isn't much longer than that.
I disagree with that. In my experience over the past 6 years with and without FI I don't think the kit made the problem much worse, maybe just a little. The problem was already there bone stock, so bottom line IMO is the Z4M does not have enough cooling capacity for the track.
Let's hope there is still enough room for a larger radiator now that the intercooler is in there! Pretty sure that's the only thing in your list that will make a difference. I'll see if I can find someone who's done it.
If I were trying to avoid limp mode, I'd short shift every gear on that straight. Just a little in every gear should make more difference to limp mode and slow you down less. I'm not even talking about short shifting really, just changing your style to shift earlier by a couple of 100 rpm.
Glad you had a better day than last time!
Please do!
One question. Have you EVER seem limp mode twice in one session? Me, never. Never ever ever. That is one thing (that and the lack of any codes being thrown) that makes me think the issue is not related to a specific temp range being breeched. Also, I bet there have been instances where you've gone into limp mode early in the session, before the car even gets to full track heat? That's what made me so hopeful for your fuel pressure solution. But I guess it's more complicated than that. It's like the ECU is making a judgement call based on a collection of measurements that have been adversely affected by rapidly increasing temps, rather than the temp itself. And because there is not one specific variable it can identify as the cause, it doesn't throw a code.
Sounds stupid I know, but that's what it seems like.
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To answer your question yes it started happening despite short shifting, and no I'm not going to settle on babying the car to work around the problem. Towards the afternoon when it was hottest it happened 4 times in one session. There really isn't an option to take it easier I'm already starting a gear higher 5th vs. 4th at the start of the straight (5th gear at 90mph is not ideal)and it was happening at the end of the straight at around 7800 rpm despite that. I'm not going to shift into 6th with 100 feet left in the straight. Even coasting the last several hundred feet it limped once. It's 100% the extra boost as I was running 230 oil temps max in the same conditions taking every gear to redline with my VT-1(I did have a M6 oil cooler on the VT-1). With that setup I had limp mode very rarely on track.