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Jeffyoung

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Woot! I gots my dry sump (TR8, EP). Needed that, oiling issues were ruining season after season.

Question on the 2mm reduction in the throttle body for the Z3. First, why just the Z3 and not all 2.5L BMW motors? That doesn't make a lot of sense as I think the consensus the problem wasn't the car/chassis or the high level of prep/driving, but the motor making more power than expected. That would be the same issue with all of the 2.5l BMW motored cars.

Second, was any dyno testing done before and after the 2mm reduction? Or is this all just a WAG?

On the ITAC, before we put a restrictor on the E36 2.5l we did a fair amount of dyno testing on size and location of thing, and I'm still not 100% sure we got it correct. Never will be 100% sure I suppose, but I was hoping the reduction here was more than just a guess.
 
Bmws bread and butter is the 2.5 I6.

That said, there's mine, early, SOHC, around 150whp output factory, and the later DOHC variants with around 180whp output. These values aren't a part of my argument so they're arbitrary but just making the point that "BMW 2.5" is a very overreaching statement.

The Z3 is its own animal, it does not share suspension or chassis (e30 rear end and unibody basically/e36 front end) or body geometry to the other coupe and sedan variants with the later DOHC engines. IMO, there is no reason to suggest that the sedan/coupe models and the Z3 should be managed together. Someone should buy Chuck Badder's 325 and run it :think:

I cannot speak to how the final value of restriction was obtained.

However I will say that relative ontrack data was collected at the following events and competitors in 2022:

Florida Super tour rounds?
Hallett:Anyone? Prather? Reynolds? Not sure.
Road America Schreyer, Brakke, others?
VIR Q1 Prather, Schreyer, Brakke, Hainsworth, others?

Unfortunately the sprints were rather poorly attended, and some other top runners were parked in '22 to get a better spread of spec lines.
 
tschreyer":2u5bsony said:
Bmws bread and butter is the 2.5 I6.

That said, there's mine, early, SOHC, around 150whp output factory, and the later DOHC variants with around 180whp output. These values aren't a part of my argument so they're arbitrary but just making the point that "BMW 2.5" is a very overreaching statement.

The Z3 is its own animal, it does not share suspension or chassis (e30 rear end and unibody basically/e36 front end) or body geometry to the other coupe and sedan variants with the later DOHC engines. IMO, there is no reason to suggest that the sedan/coupe models and the Z3 should be managed together. Someone should buy Chuck Badder's 325 and run it :think:
Click to expand...

Hello Tim!

Yes, should have made it clear that I wasn't talking about the E30s. I realize the M50 in the E36 and Z3 is a different beast at 189 whp than the E30s. We never saw the power gains in ITS in the E30 that we saw with the E36. Those 2.5s in IT trim with a stock cam and no control over the VANOS would make 215 whp.

I was in fact referring to Chuck's car specifically. It has a better rear suspension than the Z3 and the same motor right? If we think the Z3 has significantly better power to weight than the rest of EP, then the sam should generally be true of the E36 325is.
 
Yes. Better rear suspension, worse aero, more weight...

My guess is since it hasn't been campaigned and thus data captured, it hasn't been reviewed.
 
I think Chuck's 325 ran not one but two Super Tours in Atlanta - I'm willing to bet they got a Solo2 in there for a session or two.

Mike Anderson's car ran a couple Majors and I'll bet a Super Tour out west; beat some good people too. I know they have data on that car. I don't know if he's moved on or not, wouldn't blame him at all. Haven't heard from him in a while.

I don't care for the lack of transparency of the formula for lap times. Everyone gets googly eyes over the trap speeds without having any idea what mid-corner speeds are or even the difference in car weights.

Show us the formula then let's talk. Otherwise the restrictors are just whack a mole. Not very appealing to build a car towards.

And Tim, I'm hoping to see you at The Sprints. I ruptured a disc in my neck and parked the car on Doc's orders.
 
blamkin86":9giim0h3 said:
I think Chuck's 325 ran not one but two Super Tours in Atlanta - I'm willing to bet they got a Solo2 in there for a session or two.

Mike Anderson's car ran a couple Majors and I'll bet a Super Tour out west; beat some good people too. I know they have data on that car. I don't know if he's moved on or not, wouldn't blame him at all. Haven't heard from him in a while.

I don't care for the lack of transparency of the formula for lap times. Everyone gets googly eyes over the trap speeds without having any idea what mid-corner speeds are or even the difference in car weights.

Show us the formula then let's talk. Otherwise the restrictors are just whack a mole. Not very appealing to build a car towards.

And Tim, I'm hoping to see you at The Sprints. I ruptured a disc in my neck and parked the car on Doc's orders.
Click to expand...

Yea I heard about the back through the grapevine - we probably should have crossed paths in Topeka too.

I 100% agree on a level of transparency leading to performance decisions. I think someone just submitted a letter regarding just this prompted by the SM VVT BOP adjustment as well.

Hell, I'd just like to see how the decision was deduced similar to how I was structuring the above:

"We took data from these competitors at these locations, summarize the findings and don't expose the finite data"

I also think the initial request in it's entirety should be an accessible document to members.
 
My guess is that the trap speeds for the Z3 were a touch above the rest . So yeah, wack a mole down 2mm and repeat the test. No dyno needed.
 
As all you might be aware, SCCA does bring a dyno to the Runoffs and some classes are required to visit it via the compliance plans that the category chief of tech turns in prior to the event. A few years ago, the V 8 stock car series who I did tech for hired a dyno for a race a VIR and all cars where required to visit it at the end of qualifying. I worked with the operator and was the only one who observed the read outs. It certainly opened my eyes in that the several of the front runners had far less HP than some of the mid pack guys especially in GTA where the HP is limited and balanced by RPM limiting chips. (I used my own chip).
Point is how would you feel about it if I included the dyno in my compliance plan for 2023 and selected some of the front runners to see what HP is getting to the ground? And also select some who might have the same make and model who are not up front? This could show what I saw in the GTA cars, drivers and set up make a big difference in going fast.
My motorhome ( which was totally destroyed by fire the past Tuesday AM while parked at my home in Atlanta) was parked across from the dyno at VIR during the Runoffs and it sat empty for most of each day it was there so finding time is not a problem.
Everyone, have a great Christmas. We just asked Santa to bring us a new motor home for Christmas and all the things we had in our old one since we were already totally packed for the Homestead Majors.
 
What would you do with the dyno data? How would it educate adjustments? How would adjustments be validated? How would it change the compliance plan?
 
I would do nothing with it since tech only observes and reports. Information would go to Ad Hoc Committee and CRB to use along with Data Acquisition info. They could put the HP figure to the top speed info vs the actual weight of the car (Data Acquisition cars are weighed) to determine performance. Not sure about compliance plan question since that is submitted well before the event. Compliance plan would simple say cars may be selected at random post qualifying for dyno testing. There is already a dyno test plan in place. Using data acquisition information, such things as maximum RPM can be determined, etc.
And no, the information is not shared with everyone. Same as inspections now at races.
BTW, this is just a question. I don't have this planned for 2023. It's a lot of extra work for tech and my team already has three classes each day to inspect. And some of them, me included, help with other classes. In 2022, I helped with GT1, GT2, AS, FC, FF and SM.
 
That's the thing that I think Improved Touring got right. You never really objectively observe on track data. It's too dependent on weather, setup, driver, car suitability to the track, etc. Just slapping 2 mm on a restrictor doesn't make a lot of sense as part of a BoP based on data logging on track performance. I mean, does anyone have any idea whatsoever what the 2 mm will or won't do?

Dynos of course aren't entirely objective but they give some baseline. If we dynoed all cars in EP and I was right there at the same power to weight, well then, I need to shut my mouth and work on other stuff. Need to do that anyway.

But if the dyno numbers show what I suspect based on the numbers I've seen and heard -- 270 whp+ for the 2.5 VANOS motor -- then EP has a problem.
 
I hesitate to even reply to this however I feel that I should.

Prod is to me a builders class. How can I build a better mousetrap. Be it the engine, suspension, setup, aero, and yes even the driver. This isn't spec racing. To think that everyone can and will be able to build the best car out there is just not possible. Being able to build within our rules and get a little more is what these classes are all about.

To me, saying that we should dyno cars at the runoffs in prod is completely crazy. Want to kill prod, start doing it. You think Sargis would like it? Anyone here think he's got some sort of unfair advantage besides he knows how to build a killer car?

I know it's the silly season but really, get off of the internet and work on your car or yourself to make your program better.

Rant over. Sorry!
 
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