understeer help

[1977and2010]

I have a 2SS M6 with 403 rwhp. I've been autocrossing 6 or 7 times with it now and doing pretty well in my local club. Everybody really seems to like it judging by how many people ask to ride along. My suspension has Pedders bushings (radius rods, diff, and subframe), Pedders 27mm sways front/rear, Pedders SS brakelines, Pfadt trailing arms, and I got a set of rear stock wheels for front so 275/40/20 all around. I just had an alignment and front camber is -1.6, caster 6.4, toe out .02; rear camber is -1.16 and toe .04. Swaybars are set in middle settings front/rear, will definitely go full hard in rear. Tire pressures were 41 psi front and 40 psi rear.
Now the issue is the dam understeer, I guess these mods have helped a little but not a lot. The car has so much power for these smaller courses that it kills me not to be able to use it all. I beat a bunch of nice/expensive cars but I want to go faster.
I've been thinking about coils or coilovers to help with handling but really not too sure that will help. Is my only option another set of wheels and slicks, which will put into a class with mostly racecars.
The video is my first run of the day, it was a 39.6, by the end of the day I knocked it down to a 37.5.
Any suggestions or flaming will be accepted.





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[TCao]

Cool video. Looks like you had fun. You can try a couple of easy things to reduce understeer: 1. adjust the front swaybar to the softest setting and the rear to the stiffest and 2. lower the rear tires pressure. I assume you still have the OEM springs and dampers so I'm a little surprised that caster is not within factory spec of 6.7 to 7.1 degrees. More positive caster (Pfadt recommends 7.5 to 8.5 degrees), more front negative camber and less rear camber would all help decrease understeer.

[Bruce@raymondsperformance]

Looks like you are having a good time with your car.Changing to drop springs or even coil overs will help the handling but you can get some improvement by changing the rear camber more positive to help reduce the under steer and toe the front out more to help the turn in when you are auto crossing this is where I would start. Good luck.

[Avalnch]

Big car, big horse power and small course do not match. You'll never be able to pedal to the metal, ever. Being not as agressive is the key for small courses and our Camaros, but then, where's the fun in that?

[DMSDesign]

You can do a lot of add ons, but in terms of alignment, change the rear camber to -.5, the front toe to .1 toe out each wheel. Add front caster.

This will give you maximum reduction in understeer, without adding additional parts

mike
dms

[Avalnch]

Originally Posted by DMSDesign

You can do a lot of add ons, but in terms of alignment, change the rear camber to -.5, the front toe to .1 toe out each wheel. Add front caster.

This will give you maximum reduction in understeer, without adding additional parts

mike
dms

Won't this amount of toe-out in the front make the car track street roads really agressively?

[1977and2010]

Thanks for the input guys, going to do the swaybar suggestion for sure and will talk to my alignment guy. I'm still interested in lowering coils or coilovers but still don't see this helping the understeer seems more for looks, I don't know. Next mod will have to be driver, being patient and realizing that these cars will never turn as sharp as a lightweight Miata or S2000. Make my turns wider and slower, but showing that kind of restraint is so hard.

[flyby]

Get a pedders complete set up for the track, you will be shocked at the difference.

[axis]

Originally Posted by 1977and2010

Thanks for the input guys, going to do the swaybar suggestion for sure and will talk to my alignment guy. I'm still interested in lowering coils or coilovers but still don't see this helping the understeer seems more for looks, I don't know. Next mod will have to be driver, being patient and realizing that these cars will never turn as sharp as a lightweight Miata or S2000. Make my turns wider and slower, but showing that kind of restraint is so hard.

You will be pleasantly suprised at just how well this car responds to suspension mods. I just installed Pfadt lower springs and it's amazing at how much more predictable the car is now.

[Apex Chase]

Originally Posted by 1977and2010

Thanks for the input guys, going to do the swaybar suggestion for sure and will talk to my alignment guy. I'm still interested in lowering coils or coilovers but still don't see this helping the understeer seems more for looks, I don't know. Next mod will have to be driver, being patient and realizing that these cars will never turn as sharp as a lightweight Miata or S2000. Make my turns wider and slower, but showing that kind of restraint is so hard.

Sway bars and alignment for sure, but don't discount the lowering springs. There are huge benefits that go beyond just curing under steer when it comes to lowering a vehicles center of gravity, particularly when that car weights 4000 lbs. One way I explain it to people is to think back if you ever played football or have ever had any martial arts training. What is the very first thing they teach you? Proper stance and get low, bend you knees, because it is easier and quicker for you to transfer your weight. Same goes for your car.

[Rob@WretchedMS]

Originally Posted by Bruce@Raymonds Performance

Looks like you are having a good time with your car.Changing to drop springs or even coil overs will help the handling but you can get some improvement by changing the rear camber more positive to help reduce the under steer and toe the front out more to help the turn in when you are auto crossing this is where I would start. Good luck.

+1, listen to him, he knows what he's talking about

[RichJ.]

Originally Posted by Bruce@Raymonds Performance

Looks like you are having a good time with your car.Changing to drop springs or even coil overs will help the handling but you can get some improvement by changing the rear camber more positive to help reduce the under steer and toe the front out more to help the turn in when you are auto crossing this is where I would start. Good luck.

Follow Bruce's suggestion and put your front bar on the softest setting.

[1977and2010]

Originally Posted by Apex Chase

Sway bars and alignment for sure, but don't discount the lowering springs. There are huge benefits that go beyond just curing under steer when it comes to lowering a vehicles center of gravity, particularly when that car weights 4000 lbs. One way I explain it to people is to think back if you ever played football or have ever had any martial arts training. What is the very first thing they teach you? Proper stance and get low, bend you knees, because it is easier and quicker for you to transfer your weight. Same goes for your car.

Never thought about it that way, makes sense.


Thanks again everyone for the input.

[DMSDesign]

Originally Posted by Avalnch

Won't this amount of toe-out in the front make the car track street roads really agressively?

the toe out for the front will have 0 negative affect.

mike
dms

[JusticePete]

Bruce, Rich, Rob and Mike know what they are talking about. Well done Pedders Suspension Specialists! Let us know how your next event goes.

[PfadtRacing]

Originally Posted by 1977and2010

I have a 2SS M6 with 403 rwhp. I've been autocrossing 6 or 7 times with it now and doing pretty well in my local club. Everybody really seems to like it judging by how many people ask to ride along. My suspension has Pedders bushings (radius rods, diff, and subframe), Pedders 27mm sways front/rear, Pedders SS brakelines, Pfadt trailing arms, and I got a set of rear stock wheels for front so 275/40/20 all around. I just had an alignment and front camber is -1.6, caster 6.4, toe out .02; rear camber is -1.16 and toe .04. Swaybars are set in middle settings front/rear, will definitely go full hard in rear. Tire pressures were 41 psi front and 40 psi rear.
Now the issue is the dam understeer, I guess these mods have helped a little but not a lot. The car has so much power for these smaller courses that it kills me not to be able to use it all. I beat a bunch of nice/expensive cars but I want to go faster.
I've been thinking about coils or coilovers to help with handling but really not too sure that will help. Is my only option another set of wheels and slicks, which will put into a class with mostly racecars.
The video is my first run of the day, it was a 39.6, by the end of the day I knocked it down to a 37.5.
Any suggestions or flaming will be accepted.





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Josh, Autocrossing always makes for difficult set ups. Above and beyond anything else, the first thing that will effect the over/understeer balance, will be Sway Bars. It took a lot of time for us to engineer the proper balance for racing and street use in all of our sway bar products. This is because front and rear roll resistance work together to effect the overall characteristics of performance handling. The most direct components that can be upgraded to effect this are spring rates and sway bars. Spring rates are great to upgrade, but more adversely effect ride quality, and it is for that reason that sway bars are typically the starting point for getting the balance to the sweet spot you require.

So, with that said, you should investigate tuning with sway bars to solve your balance requirements for autocrossing. It is well documented that any understeer can be solved with the right sway bar upgrades. If you have any doubt, just take a look at what kind of results Erik from Torq is getting with his National autocross efforts! Not only was he one of the victorious cars down at the Camaro5Fest autocross competition, he recently had a momentous 3rd place overall at the national Holley LS Fest in Bowling Green! No other late model car could touch him! He has the balance dialed in pretty well for consistent podium finishes!

Torq Autocross thread

Give us a shout with any specific set up questions. We have been fielding autocross questions all day today and yesterday on the phones, seems to be a popular subject right now! As for us, its off to NASA Nationals this week!

[2010 SS RS]

More HP fixed my understeering issue..try getting around 600 rwph...not kidding I am totally serious here....I had serious understeer at 400 rwhp but the additional 200 allows you to kick the ass out with ease.

[1977and2010]

Give us a shout with any specific set up questions. We have been fielding autocross questions all day today and yesterday on the phones, seems to be a popular subject right now! As for us, its off to NASA Nationals this week!

PM sent

[PfadtRacing]

Josh, thanks for taking the steps toward reducing understeer with Pfadt. Post up with your findings after installing all of your new parts. We will be interested to find out how they have changed the balance of the car, and its overall competitive edge.

[1977and2010]

I'm interested and excited myself. Will post up as soon as I can. Thanks.