Any news on ITB weights???

[JeffYoung]

Sorry, we are not going to locate and set cam timing specs for 300 different cars.

The Mustang makes damn good power so it got a higher gain number.

We don't run all cars at the same gain. We run at 25% as a default with different default numbers for rotaries. We move off of the 25% if we have good data showing we should.

The older cars with crappy exhaust and econo priority engineering, will see much bigger gains than the newer multi- valve- nice exhaust- better engineered cars .
To run all of them at the same gain is not going to work.


Take the 4AG, the factory left very little on the table at stock cam lift and compression. Small gain indeed. The 16V VW is exactly the same as the 4AG. Very small gains . The stock exhaust manifold works very well with stock cams and compression. The biggest gains for both of these cars is controlling the fuel and timing map at race RPMs, after getting all of the legal compression and freeing up the rotating mass.
No way will either car make 25%. More like 8-9HP total .

I will go back to lack of cam timing rule for the IT cars. SM has gone to a much more hard value for the cam timing. For good reason. . We have guys moving the cams in the head to move the timing. Milling the head retards the timing and makes a little more upperpower. Maybe 3hp from 4800- 6400 on the VW.
The current rule states that the cam timing may be returned to stock, or may not.
If you allow milling the heads and decks. It only make sense to allow the adjustable cam wheel specifically to set the cam at stock spec..
Spec the valve opening @ stock plus or minus 2

ITAC needs to come up with good data for the cam timing, not leave open, as it is now.
Pull some valve covers, make shit happen.
I run the VW IT engines/cars that I have bought, in HProd. I usually have to reduce the cam size.

What happened to the Ford Mustang, with 88-96 HP how did it end up so heavy?

The SMAC has some vested interest issues maybe.. I put in for allowing replica (500$) tops that weigh the same, look the same ,etc .

"Not needed as tops are easy to buy" BS the SMAC guys own the legal tops and sell them for 1000$.
The HOHO tires are running off a lot of those guys now also.

[Ralf]

yes, right now the A2 is classified with the assumption that it makes ~116whp. you can run any car on that specline with GTI equipment, including engine, digifant, etc...

I can tell you that whp #'s are only used when classifying a car from "what we know" which is based on confidence in data, usually in the form of chassis dyno sheets, i.e. wheel hp. there has to be a method to work backwards to CHP, so we use a standard15% loss. again - IT classing is a wide target, not a pin head.

I did a search for where this 15% powertrain loss comes from and found some interesting articles.

http://www.modified.com/tech/modp-10...s/viewall.html
http://forums.tdiclub.com/showthread.php?t=75062
http://www.carcraft.com/techarticles...s/viewall.html

So, the 15% rule should also be just an assumption rather than a standard.

[Knestis]

It's never been more than an assumption. It's not possible to know exactly what the value should be for any individual car.

K

[Chip42]

Ralf,

that's true - but like I said, working backwards using the same loss number for everyone (well, 15 or 18% if longitudinal F/R) means that "what we know" puts all drivetrains on an even footing WRT loss. lossy, inefficient drivetrains look like lower gain motors, and higher efficiency drivetrains look like higher gaining motors. it all works out in the wash.

it's a pretty decent system for the level of accuracy we are shooting for.

[Ralf]

But you are giving the Golf/Jetta an additional 5% over other cars classified. If VW designed the drivetrain to only have a 10% loss rather than the 15% used in the formula, the chassis dyno will show a higher whp.
I have no dyno data of my own, but have been a VW fan for a long time and have a very hard time believing that with our limited allowances and a stock cam, these motors can achieve a gain of 32hp.
These cars were not restricted with emission systems like some of the domestic market. I even passed the California emission test with a gutted catalytic converter and a 268 degree cam.

[Flyinglizard]

My 12-1 prod engine rolls at 118-119. ( with 25yrs of tricks)

The 10-1 , IT legal version is about 10 less @just over 108.
Maybe, maybe right at 110 with angle milled head, loose PTW, gapless rings,Hrs into the valve seat job. fresh hand lapped valves.
Spot on CIS.

MY 1.6 Miata rolls the same dyno at 113 so I think the numbers are valid.
Florida power is about 2 less than NY power tho. Even corrected.

[Flyinglizard]

FWIW many early cars were dynoed with the very special brazilian ( VW marked ) cam . That cam is worth a solid 8-10HP , 268 duration.

The legal 020 cam was run to 6400rpm and weak over 6000. The 268 pulls well to 7200.

[quadzjr]

Mike,

How do you identify these cams? I have talked to a few MK2 guys in the SE and all are making more than your 108. At least the guys that run up front that I talk to.

angled milled head and crazy valve seat work are not legal in IT.

The 1.6 Miata should be making more than 113.. maybe your dyno is putting out numbers a little low.

Ralf,

Strickly speaking from an engineering aspect.. they do not design in a drivetrain loss.. Ideally they reduce it down as much as possible.

the drivetrain loss varies from car to car and drive train to drive train.. however, as long as you base all from the same point it really does not matter.. you are talking very small percentages at this point. 15% loss for FWD layouts and 18% loss for front engine rwd layouts are pretty common industry standards.

[Flyinglizard]

The engine that made 108-110 went 244. 5 Sebring long,on the old T 1, Right with Paul Ronnie. We swapped wins.
His new, maybe more legal car, is going 2:46, now. .
Removed 100# and ran the 268 cam , same engine /car went 243 on the new track( Michael) . Similar tires.
FWIW the alternator cut out is worth over 1 sec. 2hp?

I dont think that any legal cam and compression will make more through the CIS door.
A good digi- mega squirt car may have a little more .

It is a good maybe that the dyno is a little low, Maybe 3 but not more than that IMHO.
The 1.6 Miata runs like 113. That is about plus 12. so not bad with stock spinning stuff behind it. (I use 15% loss for the Miata.) Very legal stock bottom end. under legal compression.

The VW just pulls the Miata about 3ft per straight at 2065# and the Miata at 2200. Just expired the VW engine last race. 10yrs. not bad.

The cam is marked "Brazil", I sell all that I can get to the DR, as they have to use a "VW" marked cam. It is very good.

[Chip42]

But you are giving the Golf/Jetta an additional 5% over other cars classified. If VW designed the drivetrain to only have a 10% loss rather than the 15% used in the formula, the chassis dyno will show a higher whp.
I have no dyno data of my own, but have been a VW fan for a long time and have a very hard time believing that with our limited allowances and a stock cam, these motors can achieve a gain of 32hp.
These cars were not restricted with emission systems like some of the domestic market. I even passed the California emission test with a gutted catalytic converter and a 268 degree cam.

no we aren't. the A2 is set to a weight corresponding to a HP number established by data for WHP that is turned into an assumed CHP that then drives a weight through a standard calculation. if that data is incorrect, and it might be - we're only human, then the argument that "the A2 is classified incorrectly" holds plenty of water. but saying "you are giving a short stick to car X" based on the fact that we works a CHP number form WHP/0.85 is silly. the "standard loss" equalizes, it does not harm.

what we REALLY want to do is make cars as equal as reasonably possible within our rules. working backwards to an assumed CHP is simply keeping things at one set of equations as we have far more cars without WHP-in-IT-trim data than we do with, so we generally use published CHP. interestingly, the problems are based on pretty much everything BUT this part of the system.

[lateapex911]

Then I am very sorry for jumping to conclusions. You have always been just vague enough about the situation to make that possible though. That doesn't make it right for me to call you out publicly on it.

I'm editing my post.

No problem Chris. I like Albin. My single issue with him was that he kept saying he "knew a guy" who got great power from an MR2, and the guy was able to make weight, so he didn't see what the issue was. But, he could never dig up the dyno sheet or info on the mystery car, and that it had been sold or ..well, I don't even remember all teh details now. Bottom line was he really dug in about that car, in the face of overwhelming opposing info, and he wasn't the only one.
Now in my mind he DID think he'd seen numbers at some point, but couldn't remember the exact details or provide proof. he was, in my mind, acting in good faith. But my issue was that it was far too murky to put much weight behind such claims.
The real issue I had was with others who claimed the engine was a Formula Atlantic motor, etc etc, and the rules/process deals that were made kinda sneakily that ended up screwing the MR-2 ...again.

I probably was more detailed on the SCCA forum where the people involved had a chance to provide their viewpoints.

But no, Chis never made deals or was acting in any clear way to protect his turf.

[AE86ITA]

Well, very interesting data and I'm sure many more skeletons will come from the dead, but the original question remains...WHEN WOULD WE SEE THE NEW ITB WEIGHT DATA FINISHED!!!

Thanks guys I know you're working on it, but we need something to work with

[Robbie]

Well, very interesting data and I'm sure many more skeletons will come from the dead, but the original question remains...WHEN WOULD WE SEE THE NEW ITB WEIGHT DATA FINISHED!!!

Thanks guys I know you're working on it, but we need something to work with

Since you're so interested in getting this, perhaps you should volunteer to be on the ITAC and help collect information rather than sit on the sidelines demanding action. This is a giant undertaking. I would suggest patience.

[AE86ITA]

Since you're so interested in getting this, perhaps you should volunteer to be on the ITAC and help collect information rather than sit on the sidelines demanding action. This is a giant undertaking. I would suggest patience.

Patient we shall be then!!!

over and out,

[Ed Funk]

Volunteering to serve on the committee doesn't always work. BTDT.

[lateapex911]

IF the ITAC had been left on it's own regarding ITB, I bet it would be done by now. But yea, for reasons not entirely of it's own doing, the ITB thing has dragged on. Heck, I've been off the committee for an easy, what, 3 years I guess? And we were working on it for 2 before that,(Right kirk? Andy? Josh? Jeff?) so it's an easy 5 years in process.

[Knestis]

The problem has never been "doing it." The problem has been getting permission to "do it" such that the results would be implemented.

The fundamental problem is that the ITAC needs a generalizable approach and some key members of the PTB want a line-item veto on particular make/model options, based on what scares them.

K

[lateapex911]

The problem has never been "doing it." The problem has been getting permission to "do it" such that the results would be implemented.

The fundamental problem is that the ITAC needs a generalizable approach and some key members of the [s]PTB[/s] CRB want a line-item veto on particular make/model options, based on what scares them.

K

Allow me to be less suggestive and more to the point, !
(And, I should add, that back "in the day" when you and i were on con calls that, yes, indeed, the PTB definition fit as we had a guy on the con call that wasn't on EITHER board, yet voiced his opinion and pushed for his desires to be enacted upon......)
So, yea, maybe it should be "CRB and other behind the scenes parties)

[Kendall17]

I hope the Audi Coupe loses some weight since its original weight was based on 120hp which the car never had here in the States. Stock form in the USA is 110hp.

Ken

[Chip42]

as said previously, the problem currently is the scope of the ordeal and the umpteen different specs and tech levels we're trying to wrap our heads around. that the bulk of the actively campaigned class ISN'T hondas and toyotas and other beaten to death horses means that this info is not readily available in many cases. until everything is balanced to an agreeably objective level, the changes will not be released to the CRB. THEN you can call your black helicopters and stuff but for right now, save the fuel for the racecar.

if the car you are looking at is a modern one, chances are good the weights are going to stay as published currently as those have available published numbers that work with the process.

If it's a non MR2 4AGE toyota, you can run the numbers based on the MR2 (less50# for AE86, that x0.98 for the FX16). The audi thing might get political, can't say as we haven't gotten to it. but it did before. there's a dark cloud over it and I personally don't like that.