Z-Car weight/ITS

[JeffYoung]

Joe, are we talking about the Z or the ZX? Didn't the 280z still have 4-speed, drum brakes, et. al?

I honestly don't know - just asking.

[kthomas]

"I did forget the suspension in the 280 is heavier than the 240. I am betting a person could save about 35 to 40 labs running the early strut housings."

Not that much heavier. Couple pounds per corner maybe. Heck, some of the 240's are running 280 struts anyway, and nearly all are running 280 stub axles and other 280 bits.

I did forget about the bumpers though. I knew about the extra metal to back them up. Still, I think its possible.

6'4" and 230 lbs, well speaking as a crew chief, thats a lump o' weight in the wrong place. But I guess if he's bringing the money......

[Joe Harlan]

"I did forget the suspension in the 280 is heavier than the 240. I am betting a person could save about 35 to 40 labs running the early strut housings."

Not that much heavier. Couple pounds per corner maybe. Heck, some of the 240's are running 280 struts anyway, and nearly all are running 280 stub axles and other 280 bits.

I did forget about the bumpers though. I knew about the extra metal to back them up. Still, I think its possible.

6'4" and 230 lbs, well speaking as a crew chief, thats a lump o' weight in the wrong place. But I guess if he's bringing the money......
[/b]

That"s why god created Nascar........ if your fat ass is on the outside yer goin backards.


Jeff. 280Z= 2.8 + 5spd+R200 diff and FI....

[irondragon]

More on the Z-car weight rant.
Andy is correct. Because I am an enduro racer I have not lightened the car as much as could be achieved for sprint racing.
But that is not relevant to the question I am trying to get answered.
Which is this:
Why did ITAC/CRB choose to address the p/w ratio problem in IT by directing racers toward lightening their lower powered cars rather than ballasting up the better engined ones.??

First, approach in my view is very hard to police for class violations and potentially dangerous when done by those who don't understand chassis/suspension design.
Second approach, also in my view, is easy to police and doesn't involve tech scrutineers being asked to evaluate the mechanical consequences of material removal.

So why is the p/w ratio problem being solved in the way we currently are doing it??
And can we not do it more easily and safely??

Best Regards - Bill Miskoe

[JeffYoung]

I think you are making a broad generalization on how the weight process was done based on what happened with your car only.

What really happened was that several bogeys were established for each class -- for ITS, I believe it was the 240z and the RX7. A target power to weight ratio was established based on this bogey. Cars then either got or lost weight to make what is now known as their "process weight" - the weight at which they achieve the bogey power/weight ratio given the expected horsepower from their motor.

In S, the BMW would have gotten weight, but due to a variety of issues that we really don't need to go into again, it got an SIR instead. Other cars shed weight, although it wasn't many -- basically the 260z, 280z, 300zx and the 944.

In A, the opposite was true, several cars gained weight.

So to say that in all cases, weight was removed from cars to meet the process weight is wrong. In fact, reductions in weight were fairly limited.

[Gary L]

....Why did ITAC/CRB choose to address the p/w ratio problem in IT by directing racers toward lightening their lower powered cars rather than ballasting up the better engined ones.??

First, approach in my view is very hard to police for class violations and potentially dangerous when done by those who don't understand chassis/suspension design.
Second approach, also in my view, is easy to police and doesn't involve tech scrutineers being asked to evaluate the mechanical consequences of material removal.

So why is the p/w ratio problem being solved in the way we currently are doing it??
And can we not do it more easily and safely??

Best Regards - Bill Miskoe [/b]

You've lost me, not that it's hard to do. Ignoring the obvious roll cage decisions that must be made, where exactly were you planning on removing "material" from the vehicle structure that would have any measurable effect on the safety or integrity of the vehicle, while staying within the IT ruleset?

[Andy Bettencourt]

Which is this:
Why did ITAC/CRB choose to address the p/w ratio problem in IT by directing racers toward lightening their lower powered cars rather than ballasting up the better engined ones.??[/b]

Isn't this 6 of one and a half dozen of another? IF the cars in question can make weight, it is moot. And as Jake said, some cars gained, some cars lost. IIRC, most lost but that was because they were set rediculously high for reasons unknown.

First, approach in my view is very hard to police for class violations and potentially dangerous when done by those who don't understand chassis/suspension design.[/b]

I will flip this on you - you create a more dangerous situation with these 'people who don't understand chassis/suspension design' by making their cars heavier and harder on parts.

Second approach, also in my view, is easy to police and doesn't involve tech scrutineers being asked to evaluate the mechanical consequences of material removal.[/b]

There should be no material removal in IT, PERIOD. If your car is going to be tight on weight, do the minimum cage to be safe, buy the lightest parts (wheels, struts, exhaust, etc) and then if you are under, add in some 'optional' cage tubes.

So why is the p/w ratio problem being solved in the way we currently are doing it??
And can we not do it more easily and safely??

Best Regards - Bill Miskoe [/b]

Bill, you might have to help us understand by giving us examples of unsafe (but legal) removal - or whatever you are talking about. You came out guns blazing that the 280Z can't make 2505 with a 180lb driver. What are you basing this on?

[irondragon]

I have tried to avoid getting this topic to the stage where I have to deal with individuals.
But this is directed to Jeff Young, based on a recent response he made.
Jeff: you have mentioned the process using certain 'bogeys', whatever they are. Further you state that some cars, including my 280Z group have to ' shed weight'.
I continue to ask : has anyone who recommends 'shedding weight' ever gone into the details of how it might be legally and structurally safely done?? Anyone can cut out metal but I ask again 'can it be legally and structurally safely done'?
I have had a lot of kind suggestions about what might happen to the Z-cars but so far no one has really answered that question.
Structural safety is something that I take very seriously. In particular I respect the Datsun designers and don't choose to second guess their expertize by deciding which bits of the car I can cut out to shed weight.
Jeff, would you like to come up to my shop and show me how my car can 'shed weight' and still compete safely?
I have been in the metal bending business for about 40 years and have written reports on many failures. For this reason I don't believe that it is likely that a car that was never originally built for racing will enhance its structural integrity on the track by shedding weight. Please show how to do it.
I'll make you welcome and feed you well if you do because I'll be ahead after you show me what I don't seem to know. I take this stuff seriously.
Best Regards - Bill Miskoe

[Andy Bettencourt]

Bill,

Why are you ignoring my request to learn more about your car? By asking Jeff to help you find spots to legally and safely remove weight from your car, you are implying that it is as light as it can get - and you can't get to minimum weight - yet we already know it's an endro build...with big cell etc. Last I saw it, it had extra lighting on it.

You started this thread in a very inflammatory fashion inferring you had been unjustly wronged. You asked those responsible to explain. Well, we are here. We are asking you specific questions to help qualify the 'problem'. If a well built and safe 280Z can make low 2500's, there is no reason to be doing this. Help us understand your prep level by addressing post #16.

I also don't know why you keep stating you don't want to cut out OEM stuff...why? No rule allows you to do so other than door skins for NASCAR bars that I can think of? We have explained that some cars gained and some cars lost. If a car can make weight, less is always better, no?

If there is a mistake, it should be fixed - but you have not proven to anyone there is a mistake.

[MMiskoe]

I'm going to open my mouth & stick my foot in it too.

However since I have a 300zx which lost 140 pounds I am not pleased w/ the situation either.

A couple of questions to be answered, please enlighten me:

- why should weight become as hard to attain as the ultimate HP that the car is rated against? The '100% effort' cars will relocate the weight to their best advantage whereas the lesser thought out cars will just lug it around w/o considering it so there is still room for the 100% cars to gain over the others. This is one variable that you can level the playing field on if everyone has a weight they can reach.

- how much has anyone actually removed in weight by removing undercoating? I've removed a lot of it and can't see any appreciable gains in it. I can see 5-10 pounds across the entire car, but that's not what we're arguing about here.

- Why did the RX7 become the roll model for ITS?

- Why would anyone be pleased that they now have a minimum weight that is lower if its a weight that is not attainable? Un-attainable weights are no different than arbitrary HP numbers that no one will ever get to.

- In ITA where the weights went up & down across many cars, has there been any noticiable change? Good or bad? IE did this whole thing have any affect?

And specific to this thread, did I mis-interpert what people are saying be suggesting that the early 240 suspension bits be used on a 280? This either raises some serious update/backdate questions or legality issues, never mind I hope no one who suggests doing this is on the boat complaining that cars that are too heavy will be unsafe because the suspension is overloaded.


I'm about a week away from weighing my 300zx now that the doors are both gutted, but I am estimating that I will still be 50-60# over the new minimum and I only weigh 155# when I get out of the car (so I think I have the 'little driver' part covered). When I do, I'll post the numbers & do as my dad did & invite people to come show me the parts I missed.


Matt

[irondragon]

Andy and others:
This is not about my car. Never has been.
My question has always been:
Why was the decision made to require existing cars to lower their weights rather than to add weight to new cars with more power??
Please answer this, it is the fundamental question as it concerns many more cars than mine .

Never mind what I or other old car owners have not done. Not really relevant.
The older cars were already built and racing at weights which had been in the ITS regs for many years.We built our cars to specs in place at the time. Why should we change?
It is hard enough to find parts and keep these older ITS cars racing. We don't need now to be told that the class has been changed to accomodate newer cars and that if we want to stay competitive it is our cars that must change.
If it was the newer cars with better p/w ratios that were causing problems in IT why were these newer cars not the ones required to make changes?? Or why were they not put in a separate class from ITS??
For all the prancing about over what I have not done to change my car to avail myself of the new requirements I still have not had an answer to the first question above.
So, will someone please answer the first question at least, and then perhaps the others that follow on??
After that happens I will be glad to hear suggestions from experienced Z-car racers on how I can make my 280Z more competitive.
Best Regards as always - Bill

[Joe Harlan]

Bill, I can see weight in exhaust/ Fuel Cell/wheels/ and this is what I can see on the surface.

Want some more help how about some other photos?

The process will never be perfect and the fact is when a 280 gets doen to weight and is fully developed it will be a front runner period....

[zracre]

I believe there is an ideal power to weight formula which would pop out a parameter. All the cars currently classed have an ideal weight to be as close to equal ground as possible. Some cars are fat, some skinny and some ideal. If your car falls on one side or the other it is just one of those cars...do the best you can. There are a ton of cars to choose from and alot of effort went into getting everyone happy. not every one is. My car gets 115#...Jakes car loses more than he can take out. That is the nature of the class...they could have lowered the parameters of ITS but why?? There is pretty good balance with the formula and your issue is a by product...you cant make all the people happy all the time...

[Joe Harlan]

I'm going to open my mouth & stick my foot in it too.

However since I have a 300zx which lost 140 pounds I am not pleased w/ the situation either.

A couple of questions to be answered, please enlighten me:

- why should weight become as hard to attain as the ultimate HP that the car is rated against? The '100% effort' cars will relocate the weight to their best advantage whereas the lesser thought out cars will just lug it around w/o considering it so there is still room for the 100% cars to gain over the others. This is one variable that you can level the playing field on if everyone has a weight they can reach.

- how much has anyone actually removed in weight by removing undercoating? I've removed a lot of it and can't see any appreciable gains in it. I can see 5-10 pounds across the entire car, but that's not what we're arguing about here.

- Why did the RX7 become the roll model for ITS?

- Why would anyone be pleased that they now have a minimum weight that is lower if its a weight that is not attainable? Un-attainable weights are no different than arbitrary HP numbers that no one will ever get to.

- In ITA where the weights went up & down across many cars, has there been any noticiable change? Good or bad? IE did this whole thing have any affect?

And specific to this thread, did I mis-interpert what people are saying be suggesting that the early 240 suspension bits be used on a 280? This either raises some serious update/backdate questions or legality issues, never mind I hope no one who suggests doing this is on the boat complaining that cars that are too heavy will be unsafe because the suspension is overloaded.
I'm about a week away from weighing my 300zx now that the doors are both gutted, but I am estimating that I will still be 50-60# over the new minimum and I only weigh 155# when I get out of the car (so I think I have the 'little driver' part covered). When I do, I'll post the numbers & do as my dad did & invite people to come show me the parts I missed.
Matt
[/b]

Matt what I said was to use the 240 struts completely legal.....don't try to make something where its not. Not to be rude but the photos I have found I wouls say prep likely is the biggest issue in this deal. You don't have to race at the current weight you are welcome to run the car heavy. Fact is the 240z and the RX7 are the same as they always have been so you are no worse off today than you were last year. Good luck with this rediculous issue...

[Andy Bettencourt]

OK, we are sort of getting somewhere. I know and respect Matt and we have had some good discussions in the past so I know I can talk turkey.

- In a perfect world, prep would be easy for everyone. Some cars have to go the extra mile to make weight (ITS 944), some have to go the EM to make power (ITA Miata), some have to go the EM to make them turn (ITA NX2000). Most cars have a wart. We deal with them...

You are 50lbs in car plus 25lbs in driver over the new minimum (180lb driver assumption). There are many things I bet could get you to within 25lbs. Expensive? Yes. 9lb wheels aren't cheap but I bet you find 16 of your 75 right there...

2nd gen RX-7's have over 45lbs of sound deadening INSIDE the car. Weighed it as it came out on 2 cars.

The RX-7 isn't a 'role model' - it is one of the cars that represented the 'core' of the performance envelope for ITS - along with the 240Z. Similar bogies were used in A, B and C - and now R. A target P/W was established and weights set.

Nobody would be pleased that a weight is given that can't be made. I have yet to be shown that the 280Z can't make it so I have no idea what the beef is - and your car is SO close right now (inside 75lbs without REALLY trying). You guys prep for fun and enduro's. Would you say you have a build that in theory should be a front runner if it made minimum weight? I love you Matt but do you have a "Pro" motor? If you don't, then sniping about 75lbs is a bit disingenuous to me. YMMV.

I don't believe there were any noticable changes in ITA but you may get other opinions on that. It wasn't about comp adjustments. It was about resetting the weights in the GCR based on a process that laid the foundation for 'estimated parity' today and in the future. On-track results are not key data points until they show a preponderence of evidence that something is BROKEN, then PCA's can help the issue.

Now to Bill:

Why would we add weight to a car for no reason when another car can attain a lighter weight? It HAS TO BE about your car Bill. If your car weighed 2505, would you have started this thread? HELP US understand your prep level so we can understand the weight is bogus or you can understand you need to do some 'better' prep.

You don't have to change. Race at your old weight and finish in the EXACT SAME SPOT you usually do - or - try and take advantage of a correction to your weight and become more competitive and easier on parts. It's up to you and there is nothing illegal about coming in overweight in impound.

the cars with better power potential did move - to ITR. A new class. I feel like am running in sand here...if the 280Z can make 2505, then it has the same theoretical chance in ITS as a 240Z, RX-7, you name it. heck - obe top Nissan guy thinks it could be THE car to have! What more do you want?

Matt is familiar with the prep level of the cars that win in ITS and ITA in NER. I am GUESSING - and please correct me if I am wrong here - that you guys aren't near there...and you may never want to be - but that is not the issue - you COULD be if you wanted to. What makes it fair that some have to spend more in some areas? Nothing. IT is what it is.

What am I missing? Someone else jump in.

[MMiskoe]

In a perfect world, prep would be easy for everyone. Some cars have to go the extra mile to make weight (ITS 944), some have to go the EM to make power (ITA Miata), some have to go the EM to make them turn (ITA NX2000). Most cars have a wart. We deal with them...[/b]

Understood, but by creating weights difficult (or impossible) to achieve you have created another "wart" for some cars.

You are 50lbs in car plus 25lbs in driver over the new minimum (180lb driver assumption). There are many things I bet could get you to within 25lbs. Expensive? Yes. 9lb wheels aren't cheap but I bet you find 16 of your 75 right there...[/b]

True. Now where is the other 59 pounds coming from?

2nd gen RX-7's have over 45lbs of sound deadening INSIDE the car. Weighed it as it came out on 2 cars.[/b]

Re-read the question. I'm asking about all the stuff on the outside that takes an air chisle & wire brush to remove.

The RX-7 isn't a 'role model' - it is one of the cars that represented the 'core' of the performance envelope for ITS - along with the 240Z. Similar bogies were used in A, B and C - and now R. A target P/W was established and weights set.[/b]

Difference of nickname, but why not run the weights up on these cars so that more cars have a chance? I haven't heard this one yet.

Nobody would be pleased that a weight is given that can't be made. I have yet to be shown that the 280Z can't make it so I have no idea what the beef is - and your car is SO close right now (inside 75lbs without REALLY trying). You guys prep for fun and enduro's. Would you say you have a build that in theory should be a front runner if it made minimum weight? I love you Matt but do you have a "Pro" motor? If you don't, then sniping about 75lbs is a bit disingenuous to me. YMMV.[/b]

How do you say I haven't really tried? The car is legal and I still need 59#'s (I'm giving you the wheels as they are very attainable). We're not talking about cleaning the marbles out of the wheel wells here.

"SO close" is single digits my friend. "SO close" sweating how much fuel is in the car at the end of the race or remembering to add balast when you lose 10# off the driver over the winter.

Like I said, I'll get the car weighed and then you can tell me what else to change. I am truely curious about this.

This would be the same conversation if a HP # had been picked that was off the charts and it still wouldn't matter if I had made weight or not. Its not about if you have done the work, its about IF it can be done and what merited changing some cars down, not others up?

I don't believe there were any noticable changes in ITA but you may get other opinions on that.[/b]

So it was all for naught?

It wasn't about comp adjustments. It was about resetting the weights in the GCR based on a process that laid the foundation for 'estimated parity' today and in the future. On-track results are not key data points until they show a preponderence of evidence that something is BROKEN, then PCA's can help the issue.[/b]

Now I'm really confused. If nothing was broken, why did it change? If it was broken then they were comp adjustments.


Matt

[irondragon]

Andy and others:
I have already stated that this is not about my enduro car which will not and does not have to make a new minimum weight to be good in those races.
The question which you continue to avoid answering is this:
Why do older ITS sprint race cars built to long existing weight requirements and which cannot increase their power, have to reduce their weights because newer cars with better p/w ratios are entering the class and are changing the overall class p/w ratio which for some reason must stay the same??

You keep going on about my car and its lack of competitiveness - which in sprint racing I acknowledge is true but don't care about because I only run enduro's - while I keep asking you the fundamental questions:

- why do older sprint cars already built to long established ITS weights have to change because newer cars are entering the class and causing p/w ratio problems??
-why not have the newer cars meet the ITS p/w requirements by using ballast or race in some other class??
Please answer the fundamental questions.


And to the person that challenged my lack of willingness to meet weight requirements by posting a picture of my black and white 280Z on the dyno in Manchester : That car was wrecked and retired in 2003.
Where have you been and what relationship does that picture have to this discussion, other than to provide you an obsolete soapbox to preach irrelevant stuff from?
If you are going to use my car as a basis for criticizing my complaints about the IT classification process then at least be up to date. Come and take a look at the one I have now.
But that is not the point of all this.
Bad enough the black car got wrecked: but worse still that it is being used by someone who clearly doesn't know much about it, to involve it in a discussion that is not really about any car I race.
I say again - It's not about my car - it's about the classification process.
I race for fun so it's not about how competitive my own car is.
What I care about is ITS and right now I'm not convinced that the method used for dealing with p/w ratios is correct.
Perhaps I'm wrong and it is a good method, but I won't be convinced until people stop blathering about my lack of attempt to meet weight, and answer my question about the process.
Can that please happen?
All for now - Bill

[Joe Harlan]

Matt, What sized fuel cell do you run?

Bill, your question is confusing as hell. The 240z is one of the oldest of not the oldest ITS model listed and it did not change weight? How can you say everyone else is getting boned. The 280 has been boned from its first listing due to the fact those that originally classified it didn't hav a clue. So now the ITac does something to bring these cars closer together and your unhappy....There is just no reason I can see for you to be discouraged.

[shwah]

I have no dog in this fight, but the logic is killing me.

Cars were identified as the benchmark for each class.
Those cars were not changed (that I know of), and are just as fast today as they were before.
Some cars, including the 280Z were given a weight reduction.

I don't care if you can reach the spec weight or not, you are now free to make you car lighter than it was. Listening to you this means you will be able to make the car as light as legally possible in IT prep.
What this means is that your car will be faster and more reliable overall.
Yet the benchmark cars are just as fast as they once were....
Even if you only get halfway to the spec weight you come out ahead of where you were before the change.

And IF someone were to embark on an all out effort, I suspect they could get pretty close to the spec weight, by considering everything. That would be a big effort, and would include a bare metal shell, right radiator, right hoses, right cell, right size fuel lines, right wheels, right tires, right seat, right gauge package, right cage, right everything that you have legal control of. Sounds awful expensive to me, but so does running at the front of ITS.

Having said all of that, if someone were to give some information/data to the ITAC that verifies the weight to be unatainable, it sounds like they would be happy to listen. That is a much more likely course of events than them telling you how to prep a car they may not race.

I do wish I had this problem with my car though. I would love to shed some weight.

[Andy Bettencourt]

Understood, but by creating weights difficult (or impossible) to achieve you have created another "wart" for some cars. [/b]

There will always be tweeners.

True. Now where is the other 59 pounds coming from?[/b]

Matt, I am sure you can find the weight. You running a lightweight clutch.pressure plate? Mine is 4.4 pounds lighter than stock. Lightweight exhaust? FIA seat? Hollow sway bars? You get the picture.

Re-read the question. I'm asking about all the stuff on the outside that takes an air chisle & wire brush to remove.[/b]

We don't fine many cars with any significant undercoating. It's the interior rubberized insulation that is big for us. 45+lbs worth. I am assuming your interior is smooooooth...

Difference of nickname, but why not run the weights up on these cars so that more cars have a chance? I haven't heard this one yet.[/b]

Lets first prove that there are any significant amount of cars that CAN'T. When weights dropped, we did some research to see if they could. I think you are going to be close. Single digit close. FWIW, when I rolled of of LRP with the track record in October last year, I was 40lbs over minimum. 1.5%.

How do you say I haven't really tried? The car is legal and I still need 59#'s (I'm giving you the wheels as they are very attainable). We're not talking about cleaning the marbles out of the wheel wells here.[/b]

I am estimating based on what little I see of your cars at the track and your reactions to some of teh parts we have on our cars.

"SO close" is single digits my friend. "SO close" sweating how much fuel is in the car at the end of the race or remembering to add balast when you lose 10# off the driver over the winter.[/b]

See my LRP comment above. 10lbs on your car is what %? Come on.

Like I said, I'll get the car weighed and then you can tell me what else to change. I am truely curious aboutthis.

This would be the same conversation if a HP # had been picked that was off the charts and it still wouldn't matter if I had made weight or not. Its not about if you have done the work, its about IF it can be done and what merited changing some cars down, not others up?

So it was all for naught?

Now I'm really confused. If nothing was broken, why did it change? If it was broken then they were comp adjustments.

Matt [/b]

I explained what the change was about, not a shift in performance. It has been explained probably a hundred times on this site. The ITA classes are what they are now. No crazy overdogs as a result of some arbitrary weights. Matt, if you can get within 25lbs, I think you are all set...and how about that 'Pro' motor? You have the overbore? The extra half point in Compression? Balance/Blueprint? Ported heads and a legal valve job? Nice dyno tested intake and header? A/F mixture tweaked up on the dyno? Port matched? Like I said before, if you aren't maxing all other aspects of your program, arguing about the last 10-50lbs of minimum weight ain't keeping you off the podium.



The ITAC believes the 300ZX and the 280Z can make their minimums. If we were wrong, prove it to us and then make a suggestion - and the suggestion is going to be what? Add 50lbs to EVERY CAR IN ITS so yours can get to minimum?