944 SCCA ITS Race car setup
08-01-2002, 12:30 PM
#16
Race Director
[quote]Originally posted by fastfred92:
<strong>... as for coilovers I emailed Aaron Colwell at SCCA for a call on coilovers in the rear, he stated " weight bearing shocks are legal and could be run in addition to torsion bars, however, removing t bars would be illegal ? email me at falphin@acs-rdu.com and i will forward his reply.</strong><hr></blockquote>
Fred, I see that Aaron is Sven Pruett's assistant. Even so, it doesn't seem quite right to me. The ITCS language seems quite clear that you must maintain the same number and types of springs. This would seem to me to preclude the addition of other springs (changes the number of springs). I'll e-mail you for a copy of his reply. If this truly is legal, it certainly changes my approach.
<strong>... as for coilovers I emailed Aaron Colwell at SCCA for a call on coilovers in the rear, he stated " weight bearing shocks are legal and could be run in addition to torsion bars, however, removing t bars would be illegal ? email me at falphin@acs-rdu.com and i will forward his reply.</strong><hr></blockquote>
Fred, I see that Aaron is Sven Pruett's assistant. Even so, it doesn't seem quite right to me. The ITCS language seems quite clear that you must maintain the same number and types of springs. This would seem to me to preclude the addition of other springs (changes the number of springs). I'll e-mail you for a copy of his reply. If this truly is legal, it certainly changes my approach.
08-01-2002, 08:06 PM
#17
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George, the spring rates you use will (as you know) be dependent on:
*Shock valving
*Smoothness of tracks you run (Turn one transition at TWS etc.)
*Driver preference
I don't get wigged out if someone is running something different than I recommend because of these factors. I run 650# Front and 550# with the 2817/2812 Koni's. A real common setup we do with the Sport Yellow Koni's is 400# Front and 30mm Rear torsion bars. I consider that about max for that shock setup. I know you're planning on doing the 8611 inserts on the front...I'd have to check the valving specs on that unit...something you've probably already done. Have you decided on a rear unit?
*Shock valving
*Smoothness of tracks you run (Turn one transition at TWS etc.)
*Driver preference
I don't get wigged out if someone is running something different than I recommend because of these factors. I run 650# Front and 550# with the 2817/2812 Koni's. A real common setup we do with the Sport Yellow Koni's is 400# Front and 30mm Rear torsion bars. I consider that about max for that shock setup. I know you're planning on doing the 8611 inserts on the front...I'd have to check the valving specs on that unit...something you've probably already done. Have you decided on a rear unit?
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08-01-2002, 08:36 PM
#18
Race Director
[quote]Originally posted by Jason @ Paragon Products:
<strong>George, the spring rates you use will (as you know) be dependent on:
*Shock valving
*Smoothness of tracks you run (Turn one transition at TWS etc.)
*Driver preference
</strong><hr></blockquote>
True, although I would imagine with a double adjustable damper the valving would be selected for the expected range of spring rates. OK, I know it's not quite that simple, but close enough for a good start, wouldn't you agree?
[quote]Originally posted by Jason @ Paragon Products:
<strong>I don't get wigged out if someone is running something different than I recommend because of these factors.
</strong><hr></blockquote>
I'm with you on this. I try not to get hung up on the specifics of anyone's set-up. If there is a big difference in set-up that is widely used, I'd try to understand why, but I realize that different people can make very different set-ups work.
[quote]Originally posted by Jason @ Paragon Products:
<strong>I run 650# Front and 550# with the 2817/2812 Koni's. A real common setup we do with the Sport Yellow Koni's is 400# Front and 30mm Rear torsion bars. I consider that about max for that shock setup. I know you're planning on doing the 8611 inserts on the front...I'd have to check the valving specs on that unit...something you've probably already done. Have you decided on a rear unit?</strong><hr></blockquote>
I haven't. When I get to the point of locking down my starting point I'll certainly be giving you a call. My budget is falling into place, but I'm also about to become unemployed (my company is out of business and I'm just working on the shut-down). Once I'm working again things will start happening somewhat quickly with my car.
Based upon the Koni Motorsports catalog that can be downloaded from their web site, I'm guessing I'll end up using one of the 8212 shocks. Something tells me that catalog is somewhat incomplete though. I could be wrong I guess.
The rates I've been thinking of starting with are somewhere around what you are running. That would of course necessitate a larger, special order, set of torsion bars. Any idea what sort of time frame I should plan on for special order bars?
<strong>George, the spring rates you use will (as you know) be dependent on:
*Shock valving
*Smoothness of tracks you run (Turn one transition at TWS etc.)
*Driver preference
</strong><hr></blockquote>
True, although I would imagine with a double adjustable damper the valving would be selected for the expected range of spring rates. OK, I know it's not quite that simple, but close enough for a good start, wouldn't you agree?
[quote]Originally posted by Jason @ Paragon Products:
<strong>I don't get wigged out if someone is running something different than I recommend because of these factors.
</strong><hr></blockquote>
I'm with you on this. I try not to get hung up on the specifics of anyone's set-up. If there is a big difference in set-up that is widely used, I'd try to understand why, but I realize that different people can make very different set-ups work.
[quote]Originally posted by Jason @ Paragon Products:
<strong>I run 650# Front and 550# with the 2817/2812 Koni's. A real common setup we do with the Sport Yellow Koni's is 400# Front and 30mm Rear torsion bars. I consider that about max for that shock setup. I know you're planning on doing the 8611 inserts on the front...I'd have to check the valving specs on that unit...something you've probably already done. Have you decided on a rear unit?</strong><hr></blockquote>
I haven't. When I get to the point of locking down my starting point I'll certainly be giving you a call. My budget is falling into place, but I'm also about to become unemployed (my company is out of business and I'm just working on the shut-down). Once I'm working again things will start happening somewhat quickly with my car.
Based upon the Koni Motorsports catalog that can be downloaded from their web site, I'm guessing I'll end up using one of the 8212 shocks. Something tells me that catalog is somewhat incomplete though. I could be wrong I guess.
The rates I've been thinking of starting with are somewhere around what you are running. That would of course necessitate a larger, special order, set of torsion bars. Any idea what sort of time frame I should plan on for special order bars?
08-03-2002, 02:44 AM
#21
Race Director
[quote]Originally posted by Paul Bloomberg:
<strong>Jason,
How does cutting coils off of the front springs (250lbs springs)affect spring rates?</strong><hr></blockquote>
Here's how to calculate it:
============================
k=d^4*G/8D^3N:
k=spring rate
d=wire diameter of spring
G=shear modulus of elasticity (use 11,500,000 for a steel
spring). This is apparently a measure of the ability of a
material to resist deformation under a load.
D=diameter of the spring's coils
N=number of active coils. Active coils are those that are not
in contact with each other.
=============================
That said, don't be a monkey. Get a coilover kit from Jason. At $240 with Koni bumpstops you cannot go wrong.
<strong>Jason,
How does cutting coils off of the front springs (250lbs springs)affect spring rates?</strong><hr></blockquote>
Here's how to calculate it:
============================
k=d^4*G/8D^3N:
k=spring rate
d=wire diameter of spring
G=shear modulus of elasticity (use 11,500,000 for a steel
spring). This is apparently a measure of the ability of a
material to resist deformation under a load.
D=diameter of the spring's coils
N=number of active coils. Active coils are those that are not
in contact with each other.
=============================
That said, don't be a monkey. Get a coilover kit from Jason. At $240 with Koni bumpstops you cannot go wrong.
08-03-2002, 04:52 PM
#22
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Geo,
Don't be a donkey!
That would be nice except, I don't believe adj coil-overs are legal in my spec class, although I have them on my turbo : )
I simply wanted to know does it increase spring rate and if anyone knows what the spring rate of 250lb springs would be with removing 1 or 1.5 of the coil off the top of the spring. Most with camber plates have had to remove at least a coil to get the car down to a stock ride height anyway.
Since my simple mind doesn't work that well and since you know the formula. : ) I am assuming it would be very easy for you to give me the answer!
250lb Weltmiester springs with 1 coil removed=?
with 1.5 coil removed=?
Also how does removing weight from the car affect spring rates? With one weighing 2400 the other weighing 2700 would you want a 450 lbs spring on both or would the 2400lb car require less spring rate??
Thanks,
Paul <img src="graemlins/a_smil17.gif" border="0" alt="[blabla]" /> <img src="graemlins/a_smil17.gif" border="0" alt="[blabla]" /> <img src="graemlins/a_smil17.gif" border="0" alt="[blabla]" />
Don't be a donkey!
That would be nice except, I don't believe adj coil-overs are legal in my spec class, although I have them on my turbo : )
I simply wanted to know does it increase spring rate and if anyone knows what the spring rate of 250lb springs would be with removing 1 or 1.5 of the coil off the top of the spring. Most with camber plates have had to remove at least a coil to get the car down to a stock ride height anyway.
Since my simple mind doesn't work that well and since you know the formula. : ) I am assuming it would be very easy for you to give me the answer!
250lb Weltmiester springs with 1 coil removed=?
with 1.5 coil removed=?
Also how does removing weight from the car affect spring rates? With one weighing 2400 the other weighing 2700 would you want a 450 lbs spring on both or would the 2400lb car require less spring rate??
Thanks,
Paul <img src="graemlins/a_smil17.gif" border="0" alt="[blabla]" /> <img src="graemlins/a_smil17.gif" border="0" alt="[blabla]" /> <img src="graemlins/a_smil17.gif" border="0" alt="[blabla]" />
08-03-2002, 08:37 PM
#23
Race Director
[quote]Originally posted by Paul Bloomberg:
<strong>Geo,
Don't be a donkey!
</strong><hr></blockquote>
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
[quote]Originally posted by Paul Bloomberg:
<strong>That would be nice except, I don't believe adj coil-overs are legal in my spec class
</strong><hr></blockquote>
Ahhh.... Do they allow cutting springs? Maybe a dumb question, but it seems strange they would but not allow coilovers.
[quote]Originally posted by Paul Bloomberg:
<strong>I simply wanted to know does it increase spring rate and if anyone knows what the spring rate of 250lb springs would be with removing 1 or 1.5 of the coil off the top of the spring. Most with camber plates have had to remove at least a coil to get the car down to a stock ride height anyway.
</strong><hr></blockquote>
Doesn't anybody make camber plates for the 944/951 that attach to the top of the strut tower? That should give you an extra inch of lowering/suspension travel.
[quote]Originally posted by Paul Bloomberg:
<strong>Since my simple mind doesn't work that well and since you know the formula. : ) I am assuming it would be very easy for you to give me the answer!
</strong><hr></blockquote>
Actually, if you look at the variables in the equation, you will see that you will need to supply information that I cannot know from where I sit. If you give me the figures for the variables, it's as easy as plugging them in a calculator or a spreadsheet.
[quote]Originally posted by Paul Bloomberg:
<strong>Also how does removing weight from the car affect spring rates? With one weighing 2400 the other weighing 2700 would you want a 450 lbs spring on both or would the 2400lb car require less spring rate??</strong><hr></blockquote>
All other things being equal (including driver preference) except damping rates (want to match them to the springs/track conditions, theoretically you would lower the spring rates for a lighter car. The problem is that all things are seldom equal. But generally, yes, you would lower the spring rates for a lighter car.
<strong>Geo,
Don't be a donkey!
</strong><hr></blockquote>
<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />
[quote]Originally posted by Paul Bloomberg:
<strong>That would be nice except, I don't believe adj coil-overs are legal in my spec class
</strong><hr></blockquote>
Ahhh.... Do they allow cutting springs? Maybe a dumb question, but it seems strange they would but not allow coilovers.
[quote]Originally posted by Paul Bloomberg:
<strong>I simply wanted to know does it increase spring rate and if anyone knows what the spring rate of 250lb springs would be with removing 1 or 1.5 of the coil off the top of the spring. Most with camber plates have had to remove at least a coil to get the car down to a stock ride height anyway.
</strong><hr></blockquote>
Doesn't anybody make camber plates for the 944/951 that attach to the top of the strut tower? That should give you an extra inch of lowering/suspension travel.
[quote]Originally posted by Paul Bloomberg:
<strong>Since my simple mind doesn't work that well and since you know the formula. : ) I am assuming it would be very easy for you to give me the answer!
</strong><hr></blockquote>
Actually, if you look at the variables in the equation, you will see that you will need to supply information that I cannot know from where I sit. If you give me the figures for the variables, it's as easy as plugging them in a calculator or a spreadsheet.
[quote]Originally posted by Paul Bloomberg:
<strong>Also how does removing weight from the car affect spring rates? With one weighing 2400 the other weighing 2700 would you want a 450 lbs spring on both or would the 2400lb car require less spring rate??</strong><hr></blockquote>
All other things being equal (including driver preference) except damping rates (want to match them to the springs/track conditions, theoretically you would lower the spring rates for a lighter car. The problem is that all things are seldom equal. But generally, yes, you would lower the spring rates for a lighter car.
08-04-2002, 11:50 AM
#25
Race Director
[quote]Originally posted by Jason @ Paragon Products:
<strong>I know you're planning on doing the 8611 inserts on the front...I'd have to check the valving specs on that unit...something you've probably already done. </strong><hr></blockquote>
I have the valving specs, but not the motion ratios. I haven't gotten around to that yet.
The 8611 specs are:
143/463 Jounce
243/507 Rebound
I think this will work for the rates I want to run, but won't know for sure until I have the motion ratiios. You wouldn't happen to know them for the early 944 would you?
<strong>I know you're planning on doing the 8611 inserts on the front...I'd have to check the valving specs on that unit...something you've probably already done. </strong><hr></blockquote>
I have the valving specs, but not the motion ratios. I haven't gotten around to that yet.
The 8611 specs are:
143/463 Jounce
243/507 Rebound
I think this will work for the rates I want to run, but won't know for sure until I have the motion ratiios. You wouldn't happen to know them for the early 944 would you?
08-16-2002, 03:50 PM
#26
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You may want to consult with Greg Fordahl (Fordahl Motorsport / Seattle) he runs a 944 in ITS in the OR & NW Region SCCA. He also preps/services a "fleet" of 944 ITS cars.
Greg knows a few things about handling / driving ... he's a past SCCA auto cross National Champion (so is his wife!)
Sorry Skip! ... I'm giving away your secrets!
Greg knows a few things about handling / driving ... he's a past SCCA auto cross National Champion (so is his wife!)
Sorry Skip! ... I'm giving away your secrets!
08-21-2002, 03:48 PM
#27
Rennlist Member
[quote]Originally posted by Geo:
<strong>
I was invited to race with them a while back, but I would rather not race in a spec series. </strong><hr></blockquote>
Geo:
The 944 Cup is not actually a spec series. The short of it is you bring out your SCCA ITS or PCA I or H class 944, and have a blast running in this one class one model series. It is the only "series" you can race the 944 in and reasonably expect to be competitive.
Dave Derecola
<strong>
I was invited to race with them a while back, but I would rather not race in a spec series. </strong><hr></blockquote>
Geo:
The 944 Cup is not actually a spec series. The short of it is you bring out your SCCA ITS or PCA I or H class 944, and have a blast running in this one class one model series. It is the only "series" you can race the 944 in and reasonably expect to be competitive.
Dave Derecola
08-22-2002, 02:14 AM
#28
Race Director
[quote]Originally posted by 944Cup:
<strong>The 944 Cup is not actually a spec series. The short of it is you bring out your SCCA ITS or PCA I or H class 944, and have a blast running in this one class one model series. It is the only "series" you can race the 944 in and reasonably expect to be competitive.</strong><hr></blockquote>
True, it's not a spec series, but I'm not interested in racing in a one make or one model series either. I like diversity. I look forward to the challenge.
FWIW, I think the common thinking here that a 944 cannot be competitive in ITS is wrong. There are people who win with 944s in ITS. Not many, but they exist. Some folks have tried to tell me they are not legal cars, and perhaps that's true, but I kind of doubt it.
To win in IT takes an incredible level of preparation. Most IT cars I've seen are no where near prepared to the limit of the rules. I certainly don't expect to have a car capable of winning my first season or two. But, I think I have a good idea how to maximize my chances. Sadly, the E36 Bimmers are going to be hard for everyone to beat. It'll be fun though. I certainly expect to learn a lot in the process.
<strong>The 944 Cup is not actually a spec series. The short of it is you bring out your SCCA ITS or PCA I or H class 944, and have a blast running in this one class one model series. It is the only "series" you can race the 944 in and reasonably expect to be competitive.</strong><hr></blockquote>
True, it's not a spec series, but I'm not interested in racing in a one make or one model series either. I like diversity. I look forward to the challenge.
FWIW, I think the common thinking here that a 944 cannot be competitive in ITS is wrong. There are people who win with 944s in ITS. Not many, but they exist. Some folks have tried to tell me they are not legal cars, and perhaps that's true, but I kind of doubt it.
To win in IT takes an incredible level of preparation. Most IT cars I've seen are no where near prepared to the limit of the rules. I certainly don't expect to have a car capable of winning my first season or two. But, I think I have a good idea how to maximize my chances. Sadly, the E36 Bimmers are going to be hard for everyone to beat. It'll be fun though. I certainly expect to learn a lot in the process.
08-22-2002, 01:08 PM
#29
Rennlist Member
[quote]Originally posted by Geo:
<strong>
FWIW, I think the common thinking here that a 944 cannot be competitive in ITS is wrong.
</strong><hr></blockquote>
Geo:
If you spend a ton of money, yes a 944 can get competitve in ITS, that's why I qualified my assessment by saying " reasonable expect".
The main point I wanted to clarify for the readers was that the 944 Cup was not a spec series as you had indicated.
Good luck in ITS.
Dave D.
<strong>
FWIW, I think the common thinking here that a 944 cannot be competitive in ITS is wrong.
</strong><hr></blockquote>
Geo:
If you spend a ton of money, yes a 944 can get competitve in ITS, that's why I qualified my assessment by saying " reasonable expect".
The main point I wanted to clarify for the readers was that the 944 Cup was not a spec series as you had indicated.
Good luck in ITS.
Dave D.
08-22-2002, 02:30 PM
#30
Race Director
[quote]Originally posted by 944Cup:
<strong>If you spend a ton of money, yes a 944 can get competitve in ITS, that's why I qualified my assessment by saying " reasonable expect".
</strong><hr></blockquote>
Unfortunately, that is true for any car in IT. You could even build one of the dominant cars, but to run up front, the costs go up dramatically.
To be honest, I expect the same is true in PCA club racing and will be true in the 944 Cup. I have some friends in the SE-R community who didn't like the IT rules and felt the car cannot be competitive in ITS (I disagree) that started the SE-R Cup series - somewhat similar to 944 Cup. The team with the best parts ($$$$) and engineering is still winning. The only thing they don't have is an expensive engine because they have a hp/wt rule. I suspect when I finally build a proper IT engine for my car, it will cost about 1/3 the total cost of the car.
[quote]Originally posted by 944Cup:
<strong>The main point I wanted to clarify for the readers was that the 944 Cup was not a spec series as you had indicated.
</strong><hr></blockquote>
Yeah, that was wrong. I'm sorry about that. You certianly have some more freedom in the 944 Cup series than a spec serires.
[quote]Originally posted by 944Cup:
<strong>Good luck in ITS.</strong><hr></blockquote>
Thanks. The car is ready for the cage as soon as I find work (just got laid off ).
Good luck with the 944 Cup series. It looks like a good series and a great place for folks to get their feet wet in racing. 8v 944s are relatively cheap (if you don't mind a little work) if you buy them with soddy interiors. I look forward to the race reports.
<strong>If you spend a ton of money, yes a 944 can get competitve in ITS, that's why I qualified my assessment by saying " reasonable expect".
</strong><hr></blockquote>
Unfortunately, that is true for any car in IT. You could even build one of the dominant cars, but to run up front, the costs go up dramatically.
To be honest, I expect the same is true in PCA club racing and will be true in the 944 Cup. I have some friends in the SE-R community who didn't like the IT rules and felt the car cannot be competitive in ITS (I disagree) that started the SE-R Cup series - somewhat similar to 944 Cup. The team with the best parts ($$$$) and engineering is still winning. The only thing they don't have is an expensive engine because they have a hp/wt rule. I suspect when I finally build a proper IT engine for my car, it will cost about 1/3 the total cost of the car.
[quote]Originally posted by 944Cup:
<strong>The main point I wanted to clarify for the readers was that the 944 Cup was not a spec series as you had indicated.
</strong><hr></blockquote>
Yeah, that was wrong. I'm sorry about that. You certianly have some more freedom in the 944 Cup series than a spec serires.
[quote]Originally posted by 944Cup:
<strong>Good luck in ITS.</strong><hr></blockquote>
Thanks. The car is ready for the cage as soon as I find work (just got laid off
).Good luck with the 944 Cup series. It looks like a good series and a great place for folks to get their feet wet in racing. 8v 944s are relatively cheap (if you don't mind a little work) if you buy them with soddy interiors. I look forward to the race reports.