145 replies to this topic

[john mueller]

Great post Alex.

[Jamz14]

Thanks Alex.

[Tom Sager]

I am not sure of the root cause for the AFR problem, is it an ECU calibration issue? Wouldn't it be easier to ask for 94-95 ECU or misc hardware swap rather than a plate change? If there is a percieved difference it may be easy to ask for allowable parts/harness swap to make a 96/97 run identical to a 94/95 car. If the board see's no significant difference between the 1.8 model years I would think this would be easier to pass than a weight or plate change.

'94 - '95 is an OBDI car and '96 - '97's are OBDII. Different ECU's, wiring harnesses probably a bunch of different sensors and I'm not sure what else. A conversion could be done with some work and expense and I know some on this board have posted an interpretation of the rules that might allow a car to have a VIN and year change. Might work on a car nobody has seen before but I don't think that's a legal change. Will take another look at the rules. '94 - '95 is not on par with '96 - '97 but very very close. This could be easily addressed with a small weight or plate change. Evidence to support a stronger consensus of parity will come in the form of results and we won't achieve that until we see the top teams build or campaign 1.8 cars and having significant success in them in for more than a few select events. As the rules sit now, I doubt we'll see that especially with the '94 - '95. The entry lists of cars over the years has said a lot and those intent on winning and have the budget are usually in the right car and when they aren't they change cars.

[Ron Alan]

IMO...I think it goes like this. 99-00 is the best car to have followed closely by the 01+ and 96-97. Then the 94-95. Finally the lowly 1.6 bringing up the rear...at 2300lbs those little pads just cant stop it and its one squirrel short of a tree full

[DrDomm]

'94 - '95 is not on par with '96 - '97 but very very close. This could be easily addressed with a small weight or plate change. Evidence to support a stronger consensus of parity will come in the form of results and we won't achieve that until we see the top teams build or campaign 1.8 cars and having significant success in them in for more than a few select events. As the rules sit now, I doubt we'll see that especially with the '94 - '95. The entry lists of cars over the years has said a lot and those intent on winning and have the budget are usually in the right car and when they aren't they change cars.

Someone asked for your opinion yesterday. Well, there it is. Makes perfect sense to me.

What is the actual disadvantage in power with the OBDI ECU? Where in the power curve/rpm? Is that improved with the adjustable fuel pressure regulator? Just curious.

Anyway, it seems right now the class is based off the '90-93 max potential. The 1.8s and '99s are just handicapped to not be too much quicker. That's somewhat disappointing, and will probably have to change eventually.

[Alex Bolanos]

What is the actual disadvantage in power with the OBDI ECU? Where in the power curve/rpm? Is that improved with the adjustable fuel pressure regulator? Just curious.

It's not about OBDI or OBDII. 90-95.5 OBDI cars and 99-00 OBDII cars have a curve, for some reason 95.5-97 OBDII cars have a flat table which is interesting considering the effect of the restrictor plate. Converting a 94/95 to 96/97 is as easy as a wire harness, coil pack, and dash vin number plate swap.

[DrDomm]

It's not about OBDI or OBDII. 90-95.5 OBDI cars and 90-00 OBDII cars have a curve, for some reason 95.5-97 OBDII cars have a flat table which is interesting considering the effect of the restrictor plate. Converting a 94/95 to 96/97 is as easy as a wire harness, coil pack, and dash vin number plate swap.

Alex, I'm just a gynecologist so I'm not super educated on engine design, fuel mapping, power characteristics, etc. Are you saying that top end horsepower output levels off on the '94's, where it continues to climb on the '95.5+ cars? Or is the deficit lower in the rpm range?

Again, just for my education. I've got other areas to improve on first.

[tferranti]

I don't always race cars but when I do it's in a 94 bouncing off the rev limiter.

[Alex Bolanos]

Alex, I'm just a gynecologist so I'm not super educated on engine design, fuel mapping, power characteristics, etc. Are you saying that top end horsepower output levels off on the '94's, where it continues to climb on the '95.5+ cars? Or is the deficit lower in the rpm range?

Again, just for my education. I've got other areas to improve on first.

Mid range. Top end should be about the same.

[DrDomm]

Mid range. Top end should be about the same.

Thanks. I'd believe that just based on feel.

[Motor City Hamilton]

On my 1994, the air/fuel curve is pretty spot on below 5,500 RPM, but over this, it is pig rich. We spend a lot of time above 5,500 RPMs. There is power to be gained in the upper portion of the curve. Will be adding Dave W's fuel pressure kit and heading to the dyno. From the voice of a regional guy who can afford one afternoon at the dyno a year. I also capture A/F data in every on track session.

[Tom Sager]

The car needs help. Everyone is moth-balling them because they have no benefits (99 - peak power, sustainable power at the RP limit, stable and easier to drive; 1.6 - low weight, nible with mazdacomp rear end). I feel like the 1.8 cars are the "middle child" that doesn't get any attention paid to them. They are cars that with a decent wheel can finish in the top 5-10 at a big race, but can't win given equal prep 99 and 1.6 cars.

For those that feel a change should be considered, now is a good time to submit a letter to both organizations. Discussions on this topic among those that make decisions could be happening as we speak. Seriously, the next few days would be best.

[Brandon]

I don't always race cars but when I do it's in a 94 bouncing off the rev limiter.

You forgot to end it with "Stay speedy my friends..."

Hahahahahahaha!!!!

Signed,
'96 & Not 100% Built

[Jim Drago]

For those that feel a change should be considered, now is a good time to submit a letter to both organizations. Discussions on this topic among those that make decisions could be happening as we speak. Seriously, the next few days would be best.

First round of discussions will be Wednesday... SMAC call Wednesday night

[Ron Alan]

It was obvious in 2011, based on the changes for that year(45mm to 47mm and 2400 to 2365lbs), that someone said "we killed the 94-97 with the 2010(or 09)changes...we need to give something back!" So at the end of last season(2011)when SCCA and NASA came together and really looked hard at all the data... apparently they thought to much had been given back to the 94-97 and weakened it again...though they did weaken the 1.6 by adding weight. I get the weight argument in trying to bring all generations closer and applaud that. But as a percentage I still scratch my head when I look at the adjustments for 2012. The 94-97 went down 2mm in RP size yet only lost 15lbs, The 99 went down 3mm in RP size but lost 50lbs. This would seem to indicate the 94-97 was a overdog...yet in 2011 I didn't see the big teams scrambling to build this car, or see one in the top 10 at the runoffs??

i hope an engineer type will explain the math if my thinking is wrong here. We did go backwards this year, as did everyone, but again as in the past more than necessary IMO.

[Mike Asselta]

First round of discussions will be Wednesday... SMAC call Wednesday night

Please email those letters folks - include any data that you have, as your perspective counts!

http://www.crbscca.com/index.php

[Jim Drago]

It was obvious in 2011, based on the changes for that year(45mm to 47mm and 2400 to 2365lbs), that someone said "we killed the 94-97 with the 2010(or 09)changes...we need to give something back!" So at the end of last season(2011)when SCCA and NASA came together and really looked hard at all the data... apparently they thought to much had been given back to the 94-97 and weakened it again...though they did weaken the 1.6 by adding weight. I get the weight argument in trying to bring all generations closer and applaud that. But as a percentage I still scratch my head when I look at the adjustments for 2012. The 94-97 went down 2mm in RP size yet only lost 15lbs, The 99 went down 3mm in RP size but lost 50lbs. This would seem to indicate the 94-97 was a overdog...yet in 2011 I didn't see the big teams scrambling to build this car, or see one in the top 10 at the runoffs??

i hope an engineer type will explain the math if my thinking is wrong here. We did go backwards this year, as did everyone, but again as in the past more than necessary IMO.

Ron
Not defending just explaining as you asked
47 M to 45 MM = 8.4% smaller hole
41mm To 38 mm = 14% smaller hole

Pi makes a difference .. It is not just the 2 mm vs 3 mm change

[Jamz14]

Ron,

That is because the problem lies with the rev limiter. We saw it at willow springs and there was one minor section at buttonwillow this last weekend that we were banging on the limiter when others were not. Our choice, shortshift and then a quick downshift after that,or stay close to the limiter and off peak power when others were still pulling.

The top guys know this. I am an SM idiot compared to the top guys. There is a reason that they are not pushing to have it changed. I don't know what it is, but if they aren't behind it, there is no way my little ole letter will do anything about it. If no one wants to change it, fine. I would like it though if we were allowed to run the 4:10 torsen at the championships instead of being forced to use the 4:30 torsen. I am thinking about building up a 4:10 for the regional NASA races to see if we can get some performance back and get back into the same RPM range as everyone else. Hopefully we can get better with momentum driving if we do as we are going to lose torque.

[ralt12]

Make the 4.30 change optional for the '94-97's.

[Jamz14]

Make the 4.30 change optional for the '94-97's.

I think that would be a good place to start. It is already optional for all races except the championships.

That would need to be taken into account though if Dave Wheelers suggestions are implemented for testing procedures on diffs at the tech shed.