D.CACO

We threw the car on the corner-balancer last night. Our goal was 50% cross weight.
How are the rest of these numbers? Any suggestions? Are we on the right track?

Thanks!

00R101

What are you doing with the car? If it's NASCAR then "put some wedge in it, boy"

50% is perfect. Other than shifting weight to the back of the car by moving components like the battery there's not much else you can do. Was the corner weight done with the driver in the car? How much fuel?

descartesfool

You have 52.8% bias on the left side. I assume this is the driver in car or equivalent, and 64.8% front bias. I have never seen it proven that 50-50 wedge is the correct way to go on a car with left side bias. My theory says that you should have a % wedge closer to that of the left side bias, as when you compute load transfer and lateral grip on each of the 4 tires, a car with 50-50 wedge that has a left side bias will not corner equally left and right. If I was you, I would turn up one corner and count the turns and make a table of turns vs crossweight. Then try the car on the track at the various cross weights and see how it goes. All you need to do is move one spring up or down from your base setting. It does not take much to get 20 lbs more on one corner, which means 40 lbs more on one diagonal and 40 lbs less on the other, thus an 80 lb change. At 1180 lbs wedge you currently have, an 80 lb change would make for quite a lot in % terms (7% I think).

Also with a 65% front bias, you would benefit from moving any weight you can to the back to reduce load on front tires. This may or may not be possible, but it should be a target.

D.CACO

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 00R101 &raquo;</TD></TR><TR><TD CLASS="quote">What are you doing with the car? If it's NASCAR then "put some wedge in it, boy"</TD></TR></TABLE>

Whats Nascar? Honda Challenge H1 EK...




<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 00R101 &raquo;</TD></TR><TR><TD CLASS="quote"> Was the corner weight done with the driver in the car? How much fuel?</TD></TR></TABLE>

Driver= Yes. Fuel=same amount of fuel we would start the race with (3/4 Tank)


<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by descartesfool &raquo;</TD></TR><TR><TD CLASS="quote">
Also with a 65% front bias, you would benefit from moving any weight you can to the back to reduce load on front tires. This may or may not be possible, but it should be a target.</TD></TR></TABLE>

The only thing left to lighten on the front is to move the battery to the back...and we decided to keep the front bumper support. All in all, we still have about 100 lbs to meet our weight goal. We still have the rear hatch we need to throw lexan on, but if we start dropping weight in the rear, obviously our front bias increases, and I am not sure if that is a good thing?

Can we get a better than 65%Front to Rear ratio by adjusting the rake in the car? Should we even try? Or is 65% *good enough?

Thanks for the replies.



Modified by D.CACO at 6:45 PM 4/27/2004

Tyson

curious, what did you start out iwth and what did you do to reach where youre at now? please share. thanks.

edit: thanks for the answer. thought it might have taken more than just adjusting ride heights to achieve the 50/50 corner weights.


Modified by Tyson at 4:44 PM 4/27/2004

Outsane

We wrote everything down but from what I remember when we started we where some where in the high 40% range, but all of our alignments were also off.

So we went in did the weight adjustments by adjusting the shock length (Tein N1), and reached about 50.1% and then did the alignment and ended up at 50%.


Tim did a fine job!




Modified by Outsane at 4:35 PM 4/27/2004

DTMotorsports

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 00R101 &raquo;</TD></TR><TR><TD CLASS="quote">What are you doing with the car? If it's NASCAR then "put some wedge in it, boy"</TD></TR></TABLE>

What does "wedge" mean or imply? I have never heard this term.... Is it similar to staggering?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by descartesfool &raquo;</TD></TR><TR><TD CLASS="quote">You have 52.8% bias on the left side. I assume this is the driver in car or equivalent, and 64.8% front bias. I have never seen it proven that 50-50 wedge is the correct way to go on a car with left side bias. My theory says that you should have a % wedge closer to that of the left side bias, as when you compute load transfer and lateral grip on each of the 4 tires, a car with 50-50 wedge that has a left side bias will not corner equally left and right. If I was you, I would turn up one corner and count the turns and make a table of turns vs crossweight. Then try the car on the track at the various cross weights and see how it goes. All you need to do is move one spring up or down from your base setting. It does not take much to get 20 lbs more on one corner, which means 40 lbs more on one diagonal and 40 lbs less on the other, thus an 80 lb change. At 1180 lbs wedge you currently have, an 80 lb change would make for quite a lot in % terms (7% I think).

Also with a 65% front bias, you would benefit from moving any weight you can to the back to reduce load on front tires. This may or may not be possible, but it should be a target.</TD></TR></TABLE>

I think all US hondas or leftside drive import cars will be biased towards the left. If you look at most japanese cars the majority of the mechanical weight is on the left, to counteract the driver being seated on the right side. Now in our case, with the driver to the left, it only makes things worse.

If I remember correctly, 60/40 is about the best a production fwd car can get(front/rear). Ultimately, I would love for our car to have equal weight on all four tyres. But with a fwd, production vehicle I don't think this will ever happen.

I know there is room for improvement and we would love everyone's input!!! We are going to try and shift more weight rearward. Hopefully, I can get it to 60/40. With left and right only being 3% off, I will try and get it closer to a 50/50. Just don't want to go down the road of diminishing returns. When that time can be better spent.

Tyson:

Funny you ask....... last night when we put the car on the scales it was almost 50/50. Then I noticed two of our tires were almost FLAT! LOL Hahahaha... Once we fixed the tire pressures, we were like 73% and 27%.

If you are currently setting up your car, I would be more than happy to give you some advice or suggestions. I can't really say what I did..... it was more of a feeling I had; based upon our setup, measured numbers, and previous experience. It's kind of hard to explain.....

descartesfool

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by D.CACO &raquo;</TD></TR><TR><TD CLASS="quote">

Can we get a better than 65%Front to Rear ratio by adjusting the rake in the car? Should we even try? Or is 65% *good enough?
</TD></TR></TABLE>

Yes, 65 % can be improved upon if you move the battery back, and you should make every effort to reduce static weight on front tires. Take off 50 lbs front and add 50 lbs rear makes a big change to % values.

Here is a pic of Realtime's solution to shifting weight backwards with battery box as far rearwards a it can go (better front/rear bias), and the most opposite to driver as well (better left side bias).



As for rake adjusting, you cannot change the % of left bias or front to rear bias. The only thing you can change is wedge (same meaning as cross-weight). People who set up cars should learn this as it is a common fallacy. Don't forget to inflate your tires to the hot pressure you drive with (even though your tires are cold) since this will affect cross-weight.You are dealing with small changes in height to make large changes in % cross-weight, and tire pressure will make a difference. Just deflate one tire while car is on scales to see the effect. Record change in corner weight for one turn of spring perch and write it down.


Modified by descartesfool at 6:51 AM 4/30/2004

Knestis

Typically the term "wedge" is when the car is carrying more weight on one diagonal (LR+RF or RR+LF) than on the other - typically with weight "jacked onto" the diagonal that includes the front tire that will be on the inside of the most (or most important) corners. If I were at Roebling Road or VIR (both clockwise) I'd want the LR+RF diagonal to be "heavier." I supposed that someone could talk about having "zero wedge" but the word - to my thinking, anyway - sort of presumes that there is some disproportionality in there somewhere.

On a dedicated race car, a couple of percentage points extra static weight on that inside front will translate into a car that is using both front tires more efficiently in the corners that count, when the car is loaded dynamically. If you think that wedge is only for ovals, do the math: ANY track is going to have 360* more turn in on direction than the other - unless you are rallying - or the course wouldn't connect back on itself. Think slot car track, right?

This will vary depending on the kind of car and tires (and diff, and...) but it's arguably most important with cars that (a) are front wheel driver, (b) run on tires that are relatively more likely to be overworked, and (c) carry a large percentage of weight on their front wheels. Hmmm - sound familiar?

"Stagger" refers to the difference in tire diameters from side to side. We used to use wedge AND stagger on the Renault Cup cars, which were REALLY low power and where momentum REALLY mattered. We always felt that keeping the car free'd up in the corners was massively important.

K

EDIT - re: changing F/R bias with rake, you COULD do that. But picture how high the front would have to go to move the center of gravity rearward any significant amount. If you had the car standing vertically on the rear contact patches, you'd have 100% weight bias to the rear. (I know, not really possible but an imagination is useful in these cases.) If the front coilovers were like 11' tall, you could hit any balance between a 60/40 split and this mythical 0/100 split, right?

.RJ

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Knestis &raquo;</TD></TR><TR><TD CLASS="quote">If I were at Roebling Road or VIR (both clockwise) I'd want the LR+RF diagonal to be "heavier."</TD></TR></TABLE>

Have fun with that in south bend

Knestis

RJ's point should be well taken, by the way. At the end of the day, if the watch says it's faster, it is. It may indeed be a disadvantage in corners that go the "wrong" direction but the value added should accrue in the form of a lower overall laptime.

K

Crack Monkey

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by D.CACO &raquo;</TD></TR><TR><TD CLASS="quote">All in all, we still have about 100 lbs to meet our weight goal. We still have the rear hatch we need to throw lexan on, but if we start dropping weight in the rear, obviously our front bias increases, and I am not sure if that is a good thing?</TD></TR></TABLE>

Lighter is (almost) always better. It may skew the F/R bias more to the front, but it's still 10lbs less weight to move around.

Outsane

Just so thats its noted tires were inflated to race pressures

So all in all it seams that our cornerbalancing results are good numbers, but not perfect. Taking the bigger picture we have much more to worry about suspension wise then getting the bias's dead on, like compression, rebound, sway bar adjustments, ect..ect..

agreed?

MattD@Stoptech

j00 f00s had the swaybars disconnected, ri?

DTMotorsports

[QUOTE=Knestis]Typically the term "wedge" is when the car is carrying more weight on one diagonal (LR+RF or RR+LF) than on the other - typically with weight "jacked onto" the diagonal that includes the front tire that will be on the inside of the most (or most important) corners. If I were at Roebling Road or VIR (both clockwise) I'd want the LR+RF diagonal to be "heavier." I supposed that someone could talk about having "zero wedge" but the word - to my thinking, anyway - sort of presumes that there is some disproportionality in there somewhere.

If I understnad you correctly, we would want the wedge to help rotate the car around the turn. So for a right hand corner, our wedge should be dr-pf to help with centrifical forces; as the car makes it way around the turn. Because if the wedge was df-pr, the car would tend to push out when centrifcal forces were applied.

Is this correct? I really wish I could add a drawing to better describe what I am trying to say!

Doctor CorteZ

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">Can we get a better than 65%Front to Rear ratio by adjusting the rake in the car? Should we even try? Or is 65% *good enough?
</TD></TR></TABLE>

unless you put the engine in the back of the car you're going to have the same front to rear distribution , the cross weights are a completely different animal.

and yes , 50% RF - LR and LF - RR is what you want.

also where you using plates between the scales and tires to keep the suspension from binding ?

were your tire pressures equal side to side ?

and as Matt said were your swaybars disconnected ? and if so what happened to the crossweights when they were reconnected ?

also , do you run adjustable swaybars ?

Doctor CorteZ

and lastly , did you measure ride heights at all ? IE : suspension mount points...

thats it.

HapaHaole

Dennis, your fat. loose weight!!!!!

see you at willow!!!

HapaHaole

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by El Pollo Diablo &raquo;</TD></TR><TR><TD CLASS="quote">j00 f00s had the swaybars disconnected, ri?</TD></TR></TABLE>


he can only do that if he has adjustable drop links. if its stock he needs to keep them connected.

Johnny Mac

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by D.CACO &raquo;</TD></TR><TR><TD CLASS="quote">

We threw the car on the corner-balancer last night. Our goal was 50% cross weight.
How are the rest of these numbers? Any suggestions? Are we on the right track?

Thanks! </TD></TR></TABLE>

For Willow, not awesome.

Johnny Mac

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by D.CACO &raquo;</TD></TR><TR><TD CLASS="quote">

Whats Nascar? Honda Challenge H1 EK...






Driver= Yes. Fuel=same amount of fuel we would start the race with (3/4 Tank)


The only thing left to lighten on the front is to move the battery to the back...and we decided to keep the front bumper support. All in all, we still have about 100 lbs to meet our weight goal. We still have the rear hatch we need to throw lexan on, but if we start dropping weight in the rear, obviously our front bias increases, and I am not sure if that is a good thing?

Can we get a better than 65%Front to Rear ratio by adjusting the rake in the car? Should we even try? Or is 65% *good enough?

Thanks for the replies.

Modified by D.CACO at 6:45 PM 4/27/2004</TD></TR></TABLE>

Dennis, another shameless sponsor plug. Your busted.

D.CACO

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Johnny Mac &raquo;</TD></TR><TR><TD CLASS="quote">

Dennis, another shameless sponsor plug. Your busted. </TD></TR></TABLE>

hey now, we have nothing but love for our sponsors!

Anyways, since when did you become the sponsorship police? Last time i checked, I think we (LEE & SAM) SPONSORED YOUR BUSTED-*** CR-X with a front bumper, bumper support, headlight, etc...so you can make it to Willow this weekend.

Where's our sticker on your car, hunh?

Now YOUR busted! Buster!

D.CACO

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by El Pollo Diablo &raquo;</TD></TR><TR><TD CLASS="quote">j00 f00s had the swaybars disconnected, ri?</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SBE &raquo;</TD></TR><TR><TD CLASS="quote">
he can only do that if he has adjustable drop links. if its stock he needs to keep them connected.</TD></TR></TABLE>

us f00s had the sways connected, and they are comptech adjustables (3 level)

B HATCH

My b18c1 Time Trial and Autocross daily driver weighs in at the same as your race car. I think your can need a diet

D.CACO

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B HATCH &raquo;</TD></TR><TR><TD CLASS="quote">My b18c1 Time Trial and Autocross daily driver weighs in at the same as your race car. I think your can need a diet</TD></TR></TABLE>

For sure. Like i said earlier, we have about 100 lbs goal for weight removal. EG's are very lite tho. And, we have a pretty substantial roll cage in the car. Lots of bars.