Official 135i/128i SCCA FS/STU/STX Chat thread

[jvb6806]

Originally Posted by Fume

Can you confirm that the BMWhat BT adapter works well with Harrys in terms of showing the OBD data like speed, RPM, etc? Are you using an iPhone? I'm asking because I've been trying to find a good BT adapter for iPhone that works with Harry's since the one I have seem to capture data really slowly and inconsistently, not reliable at all.

I am using an android device... a nexus 5x to be specific.

The BMWhat adapter I have is the version 1 adapter... not sure about the version II that is currently being sold but I assume it would work as well. Those adapters seem to work better than the cheapo ELM237 adapters. I have used both and I could not get it to connect to harry's. I also did some basic coding with the BMWhat app and it worked very well. It did a better job of battery registration than my VerusPro did.

I use the GPS in my phone, but I know a few autoxers that use an external GPS with harry's and it seems to work. The one in the phone did the trick on a road course. Again, it was a bit clunky at autoX but I only tried it once.

Harry's Overlay

The throttle input graphic on the screen seems sluggish, and doesn't really catch quick throttle blips on downshifts, but it gives you an idea of where you are, in my case, wussing out into a corner and lifting too early before braking. It was my 2nd track day ever... cut me some slack! The data plots in the app are fairly useful as well for each lap.

The lap times lined up perfectly with the timing from Harry's, but with the sony cam I had to match them up... it is a little fiddly but it works really well once you get one lap to sync the rest of them for that session are synced as well. Once that is done you can output laps individually. You can set it up to automatically start and stop but it did not start for one session so I just start the video via the sony app and overlay manually.

With the Hero4 I believe you can preview the video and overlay and just press record on your phone and it is all done for you.

The interface is totally different on the iPhone. I have played around for a few seconds but all of the menu options are different on iOS so I won't be much help there.

It's my understanding that solostorm is the way to go, but I bought all of my stuff including the HD 1080p camera for about the cost of just the solostorm app.

Hope this helps... and isn't wrong.

[Fume]

Originally Posted by jvb6806

I am using an android device... a nexus 5x to be specific.

The BMWhat adapter I have is the version 1 adapter... not sure about the version II that is currently being sold but I assume it would work as well. Those adapters seem to work better than the cheapo ELM237 adapters. I have used both and I could not get it to connect to harry's. I also did some basic coding with the BMWhat app and it worked very well. It did a better job of battery registration than my VerusPro did.

I use the GPS in my phone, but I know a few autoxers that use an external GPS with harry's and it seems to work. The one in the phone did the trick on a road course. Again, it was a bit clunky at autoX but I only tried it once.

Harry's Overlay

The throttle input graphic on the screen seems sluggish, and doesn't really catch quick throttle blips on downshifts, but it gives you an idea of where you are, in my case, wussing out into a corner and lifting too early before braking. It was my 2nd track day ever... cut me some slack! The data plots in the app are fairly useful as well for each lap.

The lap times lined up perfectly with the timing from Harry's, but with the sony cam I had to match them up... it is a little fiddly but it works really well once you get one lap to sync the rest of them for that session are synced as well. Once that is done you can output laps individually. You can set it up to automatically start and stop but it did not start for one session so I just start the video via the sony app and overlay manually.

With the Hero4 I believe you can preview the video and overlay and just press record on your phone and it is all done for you.

The interface is totally different on the iPhone. I have played around for a few seconds but all of the menu options are different on iOS so I won't be much help there.

It's my understanding that solostorm is the way to go, but I bought all of my stuff including the HD 1080p camera for about the cost of just the solostorm app.

Hope this helps... and isn't wrong.

Thanks! Yeah I've had good success with GoPro 4, external GPS, and Harry's laptimer. Finding Bluetooth devices that work with iPhone is definitely more of a challenge.

Solostorm definitely seems the way to go since that seems like it's more tailored specifically for autocross but I didn't go with that approach for the same reason as you. Don't want to spend that much yet. Already had the gopro and the cost of laptimer app and the external GPS wasn't too bad.

[jvb6806]

I'm bringing this thread back from the dead so we can talk about all of our cars in one place.

I took my car to Underground Autosports in Hoffman Estates Illinois. They were a sponsor at one of the Chicago Region PDX events this year so I went to check them out.

I did 3 pulls on the dyno this afternoon with essentially all of the power adder stuff you can do in STX.

2010 128i N51
AA headers
Frankenstein Exhaust (Supersprint mid pipes, MF High Flow Spun Cats, MF Cat Back)
aFe "stage 2" intake
AA "stage 2" tune

215hp & 221lb/ft



My graph looks almost identical to the ones that are posted on the AA website. Kudos to them for accurately marketing their product and posting real numbers on their site.

[RyanDavies]

That looks similar to Kyle's AA tune graph w/similar parts (and pretty similar to my N52 AA tune graph). My Epic tune, uh, picked up a *lot* over that. (241/223 iirc). The AA tune effectively was just a CEL delete, lol.

The one thing that Kyle and I had done that few others did was the proper Burns merge. Your torque curve looks excellent (similar to mine), but power well down. I'm guessing all of that gap is in the merge/tune.

[jvb6806]

http://epicmotorsports.com/

That place? Was your tune an off the shelf email deal? Do you know if they use the same simon tool? Not really interested in buying another $700 tune and cable at this point.

my dumbass bought a car to build for lemons racing next summer... so I am going to cool it on the BMW for a bit while I get this together. $500 car is really a $3000 car.

[bNks334]

Originally Posted by jvb6806

I'm bringing this thread back from the dead so we can talk about all of our cars in one place.

I took my car to Underground Autosports in Hoffman Estates Illinois. They were a sponsor at one of the Chicago Region PDX events this year so I went to check them out.

I did 3 pulls on the dyno this afternoon with essentially all of the power adder stuff you can do in STX.

2010 128i N51
AA headers
Frankenstein Exhaust (Supersprint mid pipes, MF High Flow Spun Cats, MF Cat Back)
aFe "stage 2" intake
AA "stage 2" tune

215hp & 221lb/ft



My graph looks almost identical to the ones that are posted on the AA website. Kudos to them for accurately marketing their product and posting real numbers on their site.

Just wondering, but are these pulls with 93 octane? Im guessing the tune calls for it so it must be 93?

[jvb6806]

yeah... 93 octane. 80 degrees or so inside the shop and fantastic Chicago summer humidity. These numbers are corrected and I am going to assume they calculated the CF correctly.

[bNks334]

Originally Posted by jvb6806

yeah... 93 octane. 80 degrees or so inside the shop and fantastic Chicago summer humidity. These numbers are corrected and I am going to assume they calculated the CF correctly.

Correction factors are a standard. Can't change it expect for playing with the dynks sensor to.make it think it's hotter in the shop than it really is.

I was just wondering because I've compared countless data. You should add your pull to the "n/a dyno compilation" thread. I put a link to an excel spreadsheet in there that has every single dyno I could find input into a spreadsheet. You can edit it to add your pull and mods. Close to 200 results on there I think.

[jvb6806]

Link? I saw one on e90 post... is that what you are talking about?

[bNks334]

Originally Posted by jvb6806

Link? I saw one on e90 post... is that what you are talking about?

https://drive.google.com/open?id=1WV...xOrpRvdcNS8B8E

Doesn't look like anyone's bothered to update it. By far the best way to compare the data though... I think I left off around page 16 or 17.

[RyanDavies]

Originally Posted by jvb6806

http://epicmotorsports.com/

That place? Was your tune an off the shelf email deal? Do you know if they use the same simon tool? Not really interested in buying another $700 tune and cable at this point.

my dumbass bought a car to build for lemons racing next summer... so I am going to cool it on the BMW for a bit while I get this together. $500 car is really a $3000 car.

Different tool. My interactions with AA after having some problems with my "tune" from them were less than ideal, so I didn't have a lot of choice. I would probably go with BPC now. 20whp is a lot .

Honestly, when Kyle sent me his dyno (after he put the merge in) originally I didn't much believe it. It was crazy enough we kept pretty quiet about the numbers, until I got fed up with somebody over on E90post telling me it wasn't possible. I doubt I'll get back into the 128 seriously enough to continue development, but I do kind of want to try a 100 octane dyno tune from BPC just to see. We have two other competition cars (soon to be 3) in my household, all of which are more enjoyable at what they do than the BMW, so the 128 is not a very high priority.

With that said, as usual, the speed on course will be found in driving and setup. If the octane rule goes through, lots of Twins will be losing 10whp or so at National events (100 oct tunes help quite a bit on them), and I think that would put the 128 on equal footing on a larger number of courses.

[BimmerAg]

So with this season coming to an end, a lot of local autoX'ers are selling their old tires. I'm planning to buy a set of very lightly used Federal RS-RR's in 255/40R17. So my question is: Is it a stupid idea to try to run this size on a 7.5" wide front wheel? I'd like to stay in F Street which means I'm stuck with the stock width. I currently have 245's on the front with no rubbing at all, but they're just the Continental DWs so probably don't run wide like the 200TW tires do.

[mabrahams]

Originally Posted by BimmerAg

So with this season coming to an end, a lot of local autoX'ers are selling their old tires. I'm planning to buy a set of very lightly used Federal RS-RR's in 255/40R17. So my question is: Is it a stupid idea to try to run this size on a 7.5" wide front wheel? I'd like to stay in F Street which means I'm stuck with the stock width. I currently have 245's on the front with no rubbing at all, but they're just the Continental DWs so probably don't run wide like the 200TW tires do.

255/40/17 fit without rubbing... this is with a 17x8.5 and stock suspension. Don't see why it wouldn't be worth a test at least...

[BimmerAg]

Originally Posted by mabrahams

255/40/17 fit without rubbing... this is with a 17x8.5 and stock suspension. Don't see why it wouldn't be worth a test at least...

Sounds good, I'll give it a try! I guess I was just a little worried about how narrow the rims are. With a 255 pinched onto a 7.5" wide wheel, I feel like there might be a lot of sidewall flex. What tires are those and what's the offset on the wheels?

[mabrahams]

Originally Posted by BimmerAg

Sounds good, I'll give it a try! I guess I was just a little worried about how narrow the rims are. With a 255 pinched onto a 7.5" wide wheel, I feel like there might be a lot of sidewall flex. What tires are those and what's the offset on the wheels?

I understand; it goes against the put the widest wheel and tire combo mentality; but it’s worth a test. Wheels were 40mm around, no spacer. Tires Falken 615 (1st gen)

[bionicbelly]

Originally Posted by BimmerAg

Sounds good, I'll give it a try! I guess I was just a little worried about how narrow the rims are. With a 255 pinched onto a 7.5" wide wheel, I feel like there might be a lot of sidewall flex. What tires are those and what's the offset on the wheels?

I ran 255's on 8.5's for about six years. I would not recommend running them on a 7.5 inch wheel. (I also mount and balance tires for most of the people in my local region) It can be done, for sure, but it will not feel good, or drive well, and chances are it will be slower.

I know that everyone used to pinch 255 hoosiers and kuhmo's on 7.5 inch wheels, but street tires (and even current hoosiers) are cut from a different cloth.

I do actually have experience to support this. I ran my old 8.5 inch wheels with rs3's and my new 9"wheels with RS3's. Not only were the 9's faster, but they felt better, and gave better feedback.

[BimmerAg]

Originally Posted by bionicbelly

I ran 255's on 8.5's for about six years. I would not recommend running them on a 7.5 inch wheel. (I also mount and balance tires for most of the people in my local region) It can be done, for sure, but it will not feel good, or drive well, and chances are it will be slower.

What would you suggest for the front tire size in that case? 245? 235?

[bionicbelly]

I would think 235 would be the max. 215 or 225 would be better.

[BimmerAg]

Originally Posted by bionicbelly

I would think 235 would be the max. 215 or 225 would be better.

Sure 215 or 225 would be better for that wheel size in terms of responsiveness and feel. But to be more competitive in AutoX I feel like I want more mechanical grip. Ideally, there should be some size that gives the best compromise right? Not only do I want more grip, but I also want the car to be more balanced, and a 225 front/255 rear is still going to understeer like a bitch

[RyanDavies]

Tire dependent.

FWIW, there are a lot of vehicles running (and winning) national solo events with very pinched tires. On the current crop, 245 BFGs and Bridgestones on 7in wheels are not uncommon. The 2015 BS winner had 255s on a 7 at the front of his S2000.

I would strongly prefer to do anything I could to do add front grip, so if you can't fit a 245 up front, don't fit it in the back either.

[bionicbelly]

Originally Posted by RyanDavies

Tire dependent.

FWIW, there are a lot of vehicles running (and winning) national solo events with very pinched tires. On the current crop, 245 BFGs and Bridgestones on 7in wheels are not uncommon. The 2015 BS winner had 255s on a 7 at the front of his S2000.

I would strongly prefer to do anything I could to do add front grip, so if you can't fit a 245 up front, don't fit it in the back either.

Wow. I know this used to be the way to go, but I thought with the move from R's to street tires this trend would be completely different. I also thought there was quite a bit of testing to show that running that wide a tire on that size rim did nothing to help availible grip, as it does not allow the tire to work the way it was intended. I might do some testing with this this summer and post up some results. Not going to do any good for anyone right now, but it would be interesting.

[RyanDavies]

I briefly ran my E82 with 225F 245R RE71R, aggressively aligned, and with a moderate bar change (I had the tires laying around unused as I was acquiring parts).

It was a pushy nightmare.

I had helped do some 225F v. 245F testing on a BS S2000 that year, and the 245 was SUBSTANTIALLY faster and easier to drive, even on a 7in wheel.