[Antec800]

N63 only has 1 set of cats the s63 in the m5 has 2 sets of cats

[M550bernina]

Originally Posted by Antec800

N63 only has 1 set of cats the s63 in the m5 has 2 sets of cats

Overseas the n63 has secondary cats as well.

[choppedliver]

I've almost done my 50-75 miles.

Impressions so far in stage 2.

Gear changes are almost imperceptible in comfort. I have it start off in 2nd gear as well. Smoother than factory.

Eco Pro mode is now useful around town. Throttle response seems similar to Comfort and you get the coasting benefit (anything to save fuel around town).

As the changes are so much smoother in D you can accelerate hard and the car doesn't lurch around so much on the gear changes. In the past I'd go into Sport/Sport+ to make acceleration more comfortable by having the suspension stiffer and hence less lurching when it changed gears at WOT. No need to now.

I've only played with Sport+ briefly and the changes are much harder. Full testing soon.

I will try and get 0-100km/h times.

Near where I live, the best place is a 60km/h zone that is nice and flat. Getting to 100km/h is no issue but if I get caught it's loss of license for 3 months etc. So may only do 0-60km/h. My previous best was 1.95secs so if I can get that down to 1.7-1.8 then I would expect a corresponding drop in 0-100 times.

[WretchedRefuse]

Thanks choppedliver, your experience so far is very similar to mine. Please let us know when you are able to do some 0-60 testing. It's still too cold here in Michigan for testing - in fact we're expecting snow tonight. Has anybody else done any 0-60/0-100 runs on the xHP tune?

[choppedliver]

Originally Posted by WretchedRefuse

Thanks choppedliver, your experience so far is very similar to mine. Please let us know when you are able to do some 0-60 testing. It's still too cold here in Michigan for testing - in fact we're expecting snow tonight. Has anybody else done any 0-60/0-100 runs on the xHP tune?

It's getting colder here (5-10 celsius overnight). Perfect for power and perhaps times. Keen to get the car to the dragstrip as well to get some 1/4 mile times with xHP.

[lanlilan]

Originally Posted by choppedliver

I've almost done my 50-75 miles.

Impressions so far in stage 2.

Gear changes are almost imperceptible in comfort. I have it start off in 2nd gear as well. Smoother than factory.

Thanks for sharing your early impressions.

Anything about XHP that isn't as good as the factory programming?

[M550bernina]

Originally Posted by choppedliver

It's getting colder here (5-10 celsius overnight). Perfect for power and perhaps times. Keen to get the car to the dragstrip as well to get some 1/4 mile times with xHP.

Do you have 1/4 mile times before xhp?

[WretchedRefuse]

Originally Posted by lanlilan

... Anything about XHP that isn't as good as the factory programming?

Answering for myself, I'd say no. Eco Pro is now very usable, shifts in comfort are smooth as silk, and shifts in sport/sport+ depend on how hard I'm accelerating. Also, I can always see what gear I'm in.

For me, the only annoyance is the throttle blips when decelerating for traffic lights. This only happens when the transmission is in Sport shifting mode, not Drive. It's not really an issue because I don't use Sport shifting mode unless I'm driving pretty hard.

[lanlilan]

Originally Posted by WretchedRefuse

For me, the only annoyance is the throttle blips when decelerating for traffic lights. This only happens when the transmission is in Sport shifting mode, not Drive. It's not really an issue because I don't use Sport shifting mode unless I'm driving pretty hard.

That's good to know. My factory tuning rev-blips on downshifts when slowing down in SPORTS and especially noticeable in SPORTS+ mode.

[choppedliver]

Originally Posted by M550bernina

Do you have 1/4 mile times before xhp?

Yep. 0-100 and 1/4 mile.

0-100 was on the street and 1/4 mile on a prepped surface. Personally I think the prepped strip causes the car to bog after it launches (front wheels spin then bite and bog briefly) hence the slower 0-100 on the 1/4 mile time slip. Most were 3.8ish.

I did 4 runs all within a 10th of each other and the time slip from the strip matches dragy.



I need to somehow launch the car and avoid the bogging. Maybe less revs and walk it off the line.

[WretchedRefuse]

choppedliver That's right in line with the stock spec. Is your car otherwise on a stock engine tune?

[choppedliver]

Originally Posted by WretchedRefuse

choppedliver That's right in line with the stock spec. Is your car otherwise on a stock engine tune?

100% stock. Only mod is res delete and BMC filters.

[WretchedRefuse]

The temperature got up to 62F this afternoon so I tried a launch. The time wasn't very good (3.43 0-60) because I stink at this, but you can get a good sense of the shifting from my dashcam video. This was xHP Stage 2 in Sport+, sport shifting, and DSC off. Engine is stock except for BM3 Stage 1 tune. https://youtu.be/UYKygtEPH_M

[Manley00]

Originally Posted by WretchedRefuse

The temperature got up to 62F this afternoon so I tried a launch. The time wasn't very good (3.43 0-60) because I stink at this, but you can get a good sense of the shifting from my dashcam video. This was xHP Stage 2 in Sport+, sport shifting, and DSC off. Engine is stock except for BM3 Stage 1 tune. https://youtu.be/UYKygtEPH_M

The shifting really is a world of difference!

[choppedliver]

I tried 2 launches today and got a 3.82 and 3.85 for 0-100. Both slower than my best times. The car didn't feel fast like it does sometimes and it was warmer than ideal (20c, DA 300m and the air is dry which is not good for power).

First time the car showed launch control just as I let off the brake, and the second time it wouldn't show at all despite sitting on the brake and throttle for a good 3-4 seconds.

It did the usual launch hard, bog and then go. I'm going to experiment with less revs (say 2000rpm) and see if it will launch without bogging briefly. Likely it will launch slower but the fronts won't spin up, bite, bog and then we go again. Not sure if it will be quicker or not.

So far apart from harsh gear changes it's no faster.

More testing.

[WretchedRefuse]

We had another good day today so I did two more launches. Like choppedliver I am feeling stronger shifts but my 0-60 time is no better than with the stock tune. To see why, I posted below two Dragy runs that had the same 0-60 times. What I see on these is that the xHP tune is weaker in first gear than stock, but stronger in second and third. The net result is a 0-30 time of 1.43s stock vs. 1.57s on xHP. But 0-60 times on both are identical at 3.39s. All three pulls I did on xHP showed nearly identical acceleration curves and 0-30 times.

So clearly my xHP Stage 2 tune is delivering a weak performance right at launch but is shifting stronger than stock and not limiting torque. It looks like choppedliver is seeing something similar, although I'm not getting any wheel spin on launch using DSC off, brake boosting about 2-3 seconds, and launching at about 2800 RPM. The xHP tune is clearly not delivering the same power at launch as the stock tune.

Has anybody tried launching differently, using Stage 3, or tried playing with xHP custom settings?

Here is the BMW stock tune, followed by the xHP Stage 2 tune:

[Manley00]

Originally Posted by WretchedRefuse

We had another good day today so I did two more launches. Like choppedliver I am feeling stronger shifts but my 0-60 time is no better than with the stock tune. To see why, I posted below two Dragy runs that had the same 0-60 times. What I see on these is that the xHP tune is weaker in first gear than stock, but stronger in second and third. The net result is a 0-30 time of 1.43s stock vs. 1.57s on xHP. But 0-60 times on both are identical at 3.39s. All three pulls I did on xHP showed nearly identical acceleration curves and 0-30 times.

So clearly my xHP Stage 2 tune is delivering a weak performance right at launch but is shifting stronger than stock and not limiting torque. It looks like choppedliver is seeing something similar, although I'm not getting any wheel spin on launch using DSC off, brake boosting about 2-3 seconds, and launching at about 2800 RPM. The xHP tune is clearly not delivering the same power at launch as the stock tune.

Has anybody tried launching differently, using Stage 3, or tried playing with xHP custom settings?

Here is the BMW stock tune, followed by the xHP Stage 2 tune:

Hmmmm…. I have a JB4 on Map 1. With DSC turned off and stage 3 xHP I am definitely getting wheel spin in Launch. I don’t have a draggy so no official data. It yanks very hard! I’m chatting with another forum member right now that has their xHP dialed in.

[choppedliver]

I did some more testing last night. I had my son in the car so that is 60kg of extra weight.

Early evening runs were at 15c and I did 3.82 and 3.84.

Later, after were coming home it was 10c and the DA was -56M, so we tried again. Best was a 3.76s which was 0.06 off the best I've ever done.

Oh and this was Stage 3. Stage 3 launches are much harder and the fronts spin way more than stock launch. Sometimes I got the launch control flag but usually, after I let the brake off, not before no matter how long I sit on brake boost.

I checked and my 0-50km/h times were all slower than my fastest run but not by much, so in stage 3 it's not limiting anything at launch.

This road by the way where I tested is not bad, but the best I've ever done in the past there was 3.9 so perhaps there is an improvement relative to the surface.

I put the lack of improvement down to a few things;
1) Extra weight + heated seats and aircon (it was cold)
2) Front tyres are 2 years old and have 25,000kms on them and will need replacing this year. This alone could account for the slower times as they simply aren't gripping as well.

Did I expect miracles? Not really, and realistically it can probably only reduce shift times by a little each change which might add up over a 1/4 mile. The launch is the key.

is xHP worth it? Yes. Gains wise on a stock car I'm not sure yet, but take off in 2nd, the super smooth changes in D and a useful eco mode alone are worthwhile in my opinion. I expect benefits when tuned in terms of performance.

Next thing is to work out why sunroof starting squeaking/rattling after the last launches. It's like it's come loose or something. Which is weird. Maybe it was the cold weather.

And soon off to the drag strip to test. Whether or not I test drag mode or not depends on how worried I am about braking something.

[WretchedRefuse]

Well this thread hasn't seen a lot of action lately so I thought I'd post a quick update. Earlier this week I reached out to xHP and asked about my weak 0-30 time. They suggested a few tweaks:

1. Stage 3 tune.
2. Custom launch control with Torque +36 and Scale 15%.
3. Torque reduction for upshifts: -10% for 1-2 and 2-3 shifts.

Those three changes finally reduced my 0-30 and 0-60 times, although not by much and I'm still seeing a significant dip in acceleration from about 0.4-1.2 seconds. If they have any more suggestions I may give it another go, but otherwise I'll be content to wait for them to update the tune and hopefully get rid of that dip. I'll probably revert to Stage 2 in the meantime since it's a little smoother in Comfort/D than Stage 3.

I'd love to know how others are doing! Are you also seeing results similar to mine?

[CHicksM575]

I didn't see this question asked, if it was I apologize.

I have a stage 1 CarBahn tune, can this be used on top of that?

TIA.

[Bjames93*]

Yes

[G30M]

Originally Posted by choppedliver

Well, colour me confused!

Took the car to the local exhaust shop and my car doesn't have secondary cats!. Where they would be is a big fat pipe.

I don't know if this because it's an Australian model or because it's pre-LCI 2020 and hence there changes on the LCI cars.

It saves some cutting but also means any secondary cat delete benefit won't be realised.

I do know some Australian cars that the press test were doing 0-100 in 3.6 seconds which is about 3.5 0-60 or a smidge better. That could be down to no secondary cats.

xHP it is.

hmm .. do you have pics? keen to check mine!