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View Full Version : car pulls to the right after swap



Lagos
12-22-2004, 01:45 PM
every since i have finished my swap, ive had this small issue. when im on the expressway at high speeds the car will slightly want to pull to the right as soon as i give it some gas/boost in 5th gear. ive had an alignment done, so that shouldnt be the issue. is this normal TQ steer from doing the swap?

galcrazi
12-22-2004, 02:14 PM
u shouldnt be experiencing that much tq pull with your current mods, ESPECIALLY on the highway. there are a couple of things.... a sticky caliper, uneven worn tires, tire balancing issues. trial and error is ur best bet to fix this

Lagos
12-22-2004, 02:30 PM
i have one new axel and one original one...you think this may have something to do with it?

Mister2T
12-22-2004, 02:50 PM
I dont think so, or at least it shouldnt have anything to do with it, i'll tell you what just give me the car, sign the title over to me, then when i figure it out ill let you know so the next swap you do you will know :)

spoolin_gt
12-22-2004, 06:40 PM
make sure your tires are balanced...make sure that your tires are installed properly in the right direction...

galcrazi
12-22-2004, 08:33 PM
ya axel idea is def out... not possible

Trance4c
12-22-2004, 10:34 PM
you need to get an alighnment done after any major work like that. You say you have had one done.. well, I don't think it was done right. You need to go back.

If the car is going to pull anywhere, it should be to the left which is the shorter axel.. not to the right when talking about torque steer. So its not axels, or torque steer.. its a crappy alighnment. hate to say it.

Lagos
12-23-2004, 02:27 AM
this is how the car was right after the swap...
http://www.gunstig.org/6gc/images/alignmentbefore.JPG


and this is how it should be now after the alignment...
http://www.gunstig.org/6gc/images/alignmentafter.JPG

Dr.Auto
12-23-2004, 04:50 AM
Get that thing re-alligned! Everything looks good except for the front caster. Caster pulls to the most negative side, in this case to the right according to your pics. The guy that did the allighnment was probibly trying to comensate for road crown by giving a .2-.5 deggree split between the two sides. But he went the wrong way. So that will pull right. Also I would want just a little more toe in for the front, I would shoot for .08-.010 degrees toe in. It just stablizes it a little more without it getting squirmy at higher speeds. Besides being that little amount of toe it could be toeing out under accel but is unlikely unless you have worn suspension components or old rubber bushings allowing the control arms or strut mounts to flex more so than normal.

The rear camber should be closer together. As it is it will pull to the left also but it's on the rear wheels so you will see the opposite with rear wheel steering which will make the car actually go right. However camber isn't a allignment angle that will really induce anything noticable untill over .5 degree split. And even less of an effect on the rear than on the front. I would just want to get them closer together to make cornering traction more simular from left to right. The rear camber is considered non-ajustable according to allignment shops. You can adjust it, but if you want them to they usally charge you more. The reason being is you have to replace the strut bolts usally to obtain enough movement in the knuckle to strut mount to properly adjust. It can be very time consuming in many cases and is not included in a normal allignment.

http://www2.freepichosting.com/Images/421587155/6.jpg

Do not rule out torque steer caused by axles. The left axle is shorter and will not flex as much as the right side. That will induce a pull to the right untill the right hand axle "unwinds" from torque loads then it will pull left. Just the opposite of the Honda boys because Toyota engines are installed on the correct side of the car (passenger). And Hondas for the most part are backwards being installed on the wrong side (drivers). So that puts the longer axle on the other side of the car and causes it to torque steer differently.

Also another question I would be more interested in is have you gone to wider tires and/or rims since your swap? Because the wider the tire/rim combo the more aggressively it will pull in ruts.

Hooligan
12-23-2004, 05:08 AM
Dr. Auto is right...torque steer will always be in the direction of the longer shaft (given that both shafts are equal in diameter).

theta (angle of twist) depents on the torque, length, polar moment of inertia, and stiffness of the material (theta = (T*L/J*G). Length is the only thing that changes, so the degree of twist is larger (numerator).

Lagos
12-23-2004, 05:21 AM
the tires are 205-40-17s .... ive been thinking of going to 225-45-17s in the future, but so far the tires are the same ones i had before the swap.

DR.Auto, can u give me the exact settings you would recomend for camber, caster and toe for each wheel?

this is only something that i notice in 5th gear at speeds of 60+mph.

TRDmkII
12-24-2004, 03:24 AM
one thing i've noticed a lot recently with cars and customer complaints is that on the freeway the car will go with ruts in the road...could it be that...have you tried all different lanes, and other roads...does it always happen in the same spot. Those angles aren't out enough to cause a pull imo...

Dr.Auto
12-24-2004, 05:36 AM
One thing to consider when doing allignments is that yes you have specs, but you can still put it in spec and not have it correct. Now whoever did the allignment on that does have it in spec. In fact in comparison to what it was he did a good job. But most guys compensate for road crown by purposely making the car pull slightly to the left so that when you are driving on the "common" road it will go straight. Most guys accomplish this by spliting the caster .2-.5 degrees with the lesser caster value being on the left and making the car pull that dirrection. I will not try to explain why this happens because it involves geometry that I don't feel like going into right now.

Specs are as follows:

Front camber = -.8 degrees +/- .8
Front caster = 2.1 degrees +/- .8
total front toe = 0.00 degrees +/- .20

Rear camber = -1.2 degrees +/- .8
Total rear toe = .35 degrees +/- .20

So you can clearely see that the tech did his job. It is in spec. But if most guys put in a .2-.5 degree split in caster to compensate for road crown and it is enough to make it go straight on crowned roads, then don't you think that if he split it the wrong dirrection that it would pull right even greater on crowned roads? It may, and probibly will go straight on a flat surface, but probibly amplifies when on crowned roads. Allighnments are almost like art.

If your cruising down the road at 60MPH+ then I highly doubt you are experiancing torque steer. You'd have to have some crazy HP to get torque steer at that speed.



TRDmkII one thing i've noticed a lot recently with cars and customer complaints is that on the freeway the car will go with ruts in the road...could it be that...have you tried all different lanes, and other roads...does it always happen in the same spot. Those angles aren't out enough to cause a pull imo...

I have also noticed this. Alsot of it is having a "sport" tire. Sidewall rigidity I belive is to blame for that. It usually goes away (but not totally) with economy tires. Some of it is also the type of suspension the car has.

Lagos
12-24-2004, 04:10 PM
the reason why i was thinking it must be some type of TQ steer, is because the car will not do this while just cruising at 65+ ... the pull to the right will happen when i give it gas and the boost comes on.

so basically, i could be going 80mph, and the car dosnt pull at all. then i give it some gas, and it will pull to the right for a second or two.

Dr.Auto
12-24-2004, 09:24 PM
I know this is difficult but try to find a road with no road crown and try it again. You will probibly not experiance it. I ithink most people would almost consider that normal operation. Does it pull hard? Like I said before it could be a combination of things all reacting at once. Between that split with your caster, "sport" tires, possible torque steer, and the fact that you have rubber suspension bushings allowing suspension component flex could all work together and produce this result. You might not ever be able to completely get rid of it. At least not without seriousely effecting comfort of some kind in some other way. Like herd rubber bushings, or economy tires. Re-allighning the car so it doesn't pull right on accel......may not go straight the rest of the time ect ect.... You might have to just get used to it. But one thing to consider is adjusting that caster will require some work and you will be charged more to get it changed. If it was my own car I have my own methods of adjustment that I would perform, but I would also have a certain goal in mind for the car. I would also be converting to hard rubber bushings and allot of other stuff. So if you can just get used to it it would be the cheapest. And as I stated earlier, allignments are an art, and yes yours is in spec and the tires will not abnormally wear. However that sp[lit in caster will pull to the right and is considered non-adjustable. But if it were fixed I think you condition would be less significant. I must admit that if I were doing the allignment for a custimer and it turned out as is right now I would call it good and note something about the caster bacause I'm not getting paid to fix it. And most custimers don't want to pay the extra money to do so. My car on the other hand....especially my auto-x car I want exact! That is the key to making the car more stable at higher speeds. And having the allignment right on when racing is very important.