Turning issue

TYTILIDIE

TYTILIDIE

METH HEAD
I am in no real way interested in doing autocross anytime soon but, I noticed that when I turn at a high speed that my Ty seems to want to go straight. Example. About a month ago, I was goofing off by my house and there is an on ramp to a bridge where as you are merging, the road goes up hill at a pretty decent incline and turns to the right. It was the middle of the night and I was out to beat the truck up. So as I stab the throttle as I see no one is coming, I hot about 60-65 in this long turn and it seemed to me that the truck wasn't turning, felt kind of like it was sliding actually. So I let off the gas and all was well.

What (other than I shouldn't be driving like this on a public road) does this mean? Is the Ty just too heavy for this type of driving? My wife's Ty has a stock suspension and hers bites the road, in fact, it feels like it will roll before it slides. I have coil overs, tube arms, beltechs in the rear with KYB Monomax shocks.
 
BMFB

BMFB

Not to scale
Re: Turning issue

its just to heavy with to much power going onto to little a footprint. your asking those front tires to carry you through sharp turn at 70 and to put down alot of power trying to accel. The tires only have so much grip. I notice it on the autox track as well, you kinda have to enter a corner with enough speed to make it through and accel lightly through it otherwise it will plow. If you gank it you can get some oversteer, but its a short wheelbase, and it can come around fast.

Also its normal, your trucks fine, if you wanted to improve it you could try to stiffen the front up so that the weight is distributed more evenly across both tires up front. Shocks really wont help, you only real solutions are coil overs, or just dropping the front to point of sitting on the bumb stops (not really a good idea, but I autox'ed like that once and it was a noticable improvment over stock regarding handling) the reason I say shocks wont help is that they can't carry the weight of your truck. you need there to be more force applied to your lower control arm vs your frame so that it wont dip as much and it will stay flatter, shocks will only help how fast this can happen.
 
BoostedSUV

BoostedSUV

Active member
Re: Turning issue

I lost a rim to that scenario. I turned, the truck didn't.. Lol that was on stock suspension and stock wheels and tires.
 
TYTILIDIE

TYTILIDIE

METH HEAD
Re: Turning issue

Hmm. This makes me wonder, why waste money on coil overs? Yeah I am more used to the rear wheel drive feel. I haven't tried to go fast in turns since I owned my Corvettes. Now that I have dumped all this money and time in to my TY for suspension, I thought I'd give it a whirl and see what it could do. Not much I guess.
 
BMFB

BMFB

Not to scale
Re: Turning issue

you don't think so? just because you can't just floor it around every corner and have it just magically make it doesn't mean you've wasted your money. Go take a 450 hp vette (Im guessing thats about how much power you make, its about where I am) and with no traction control just floor it around an onramp corner and see which way you end up pointing. you just gotta be smooth with it. I can take my ty around a track just about as fast as anything else out there this isn't a gutted purpose built race car, and I do it on ancient technology with full leather seats, and I really don't have anything all that fancy, and I am still a novice driver.
 
TYTILIDIE

TYTILIDIE

METH HEAD
Re: Turning issue

BMFB said:
you don't think so? just because you can't just floor it around every corner and have it just magically make it doesn't mean you've wasted your money. Go take a 450 hp vette (Im guessing thats about how much power you make, its about where I am) and with no traction control just floor it around an onramp corner and see which way you end up pointing. you just gotta be smooth with it. I can take my ty around a track just about as fast as anything else out there this isn't a gutted purpose built race car, and I do it on ancient technology with full leather seats, and I really don't have anything all that fancy, and I am still a novice driver.
Click to expand...

Believe it or not, the Typhoon is not the only vehicle I have ever driven or owned. I have driven several newer Vettes including the C5 Z06's and trust me when I tell you this, you CAN turn in those ****ing things. Generally they will get sideways before they just go straight. I also know how to drive. I can feel something isn't right here. It could be the characteristics of the truck itself and just plain is what it is but seems it should do a little better than what it does.

I really shouldn't say I have wasted the money because I do like how it makes the truck launch and the overall ride feel so I can take that back. Just not happy with the turning performance. Thought about auto crossing it someday for shits and giggles but so far my experience makes me want to stick to something else for that event.
 
SikVSix

SikVSix

New member
Re: Turning issue

From what little rc dirt oval I raced, if I wanted more turning I needed softer front springs or stiffer rears. Guessing the coilovers have a higher spring rate than the stock torsion bars so you're gonna have less traction in front. Need to balance it out with stiffer rears or something if you want your high speed turning back.
And I'm def not an autocrosser or any kind of chassis expert so I might be wrong, just my thoughts.
 
DJ B

DJ B

New member
Re: Turning issue

I did the same, practically stock, with a Porsche 911 GT3 in front of me. These things are also AWD.
I made the turn as easily as the 911, but on the exit he floored it, and I let him go past 120 mph.
There was a mutual understanding. :)
 
K

Kenny99

New member
Re: Turning issue

TYTILIDIE said:
I am in no real way interested in doing autocross anytime soon but, I noticed that when I turn at a high speed that my Ty seems to want to go straight. Example. About a month ago, I was goofing off by my house and there is an on ramp to a bridge where as you are merging, the road goes up hill at a pretty decent incline and turns to the right. It was the middle of the night and I was out to beat the truck up. So as I stab the throttle as I see no one is coming, I hot about 60-65 in this long turn and it seemed to me that the truck wasn't turning, felt kind of like it was sliding actually. So I let off the gas and all was well.

What (other than I shouldn't be driving like this on a public road) does this mean? Is the Ty just too heavy for this type of driving? My wife's Ty has a stock suspension and hers bites the road, in fact, it feels like it will roll before it slides. I have coil overs, tube arms, beltechs in the rear with KYB Monomax shocks.
Click to expand...
The biggest issue is the amount of front bias from the viscous coupled TC. It's just too much and rears it's ugly head more when you are on the throttle. Sharing forward traction with lateral loading just overcomes the traction coefficient of the tires. While there are more issues that need to be dealt with, this is one that will never completely go away until the TC is dealt with.

I am working on some AWD stuff right now that we are finding performs extremely well with a 95/5- 98/2% split with 95-98% to the rear with the ability to lock the TC 100% instantly. There also needs to be an adjustment in allowable wheel slip. GM usually uses a default number of 6% wheel slip before the front is seeing full coupling lock in. This corresponds to a tires maximum traction coefficient during inclement weather. This doesn't really allow enough rear slip for power on oversteer. The rear slippage needs to be upward of 15%. That is about the max coefficient of traction for a street tire to optimize forward bite, at the same time is enough slip to induce throttle on rear steering. The difference between a viscous coupling and a clutch apply TC is stunning. The same goes for a biasing differential which looks like may become a reality for these trucks. The torque bias diff will outperform either an open or LSD on the twisty stuff.

The fix is way doable if you are into the S-series as much as I am (fanatic):tup:
 
T

TY162

New member
Re: Turning issue

Kenny99 said:
The biggest issue is the amount of front bias from the viscous coupled TC. It's just too much and rears it's ugly head more when you are on the throttle. Sharing forward traction with lateral loading just overcomes the traction coefficient of the tires. While there are more issues that need to be dealt with, this is one that will never completely go away until the TC is dealt with.

I am working on some AWD stuff right now that we are finding performs extremely well with a 95/5- 98/2% split with 95-98% to the rear with the ability to lock the TC 100% instantly. There also needs to be an adjustment in allowable wheel slip. GM usually uses a default number of 6% wheel slip before the front is seeing full coupling lock in. This corresponds to a tires maximum traction coefficient during inclement weather. This doesn't really allow enough rear slip for power on oversteer. The rear slippage needs to be upward of 15%. That is about the max coefficient of traction for a street tire to optimize forward bite, at the same time is enough slip to induce throttle on rear steering. The difference between a viscous coupling and a clutch apply TC is stunning. The same goes for a biasing differential which looks like may become a reality for these trucks. The torque bias diff will outperform either an open or LSD on the twisty stuff.

The fix is way doable if you are into the S-series as much as I am (fanatic):tup:
Click to expand...

Would a wider tire(more traction) on the rear exaggerate this problem some what? ie (r)315(f)275 ?
 
QuinnSY

QuinnSY

Donating Member
Re: Turning issue

What tire size and brand is on each TY?
I used to have Eagle F1s on my Syclone Which handled incredible and had a bulletproof side wall, but was a rough ride. Then I switched to Continential Extreme Contacts DW and they are more comfortable, but every fast corner felt like I was leaning and not safe. I really hate the tires and am going to switch back.
 
TYTILIDIE

TYTILIDIE

METH HEAD
Re: Turning issue

My TY has Sumitomo HTRZII 245/45/17-Front 285/35/18-rear
Wifes Ty has Sumitomo HTRZ 245/45/17-Front 315/35/17-rear
 
K

Kenny99

New member
Re: Turning issue

TY162 said:
Would a wider tire(more traction) on the rear exaggerate this problem some what? ie (r)315(f)275 ?
Click to expand...
It will exaggerate the situation for sure. When you aren't getting the 12+ percent wheel slip because of tire size, you aren't using the full potential of the tire. Anything more than the ideal size is unnecessary mass. That statement is from a pure racing theory standpoint. In the real world there are pros/cons to each and no small part is the look.

Quinnster said:
What tire size and brand is on each TY?
I used to have Eagle F1s on my Syclone Which handled incredible and had a bulletproof side wall, but was a rough ride. Then I switched to Continential Extreme Contacts DW and they are more comfortable, but every fast corner felt like I was leaning and not safe. I really hate the tires and am going to switch back.
Click to expand...
I prefer the extreme contacts because of ride quality and they might be a better handling tire, but they do feel sluggish. Taking my toe settings to 0 brought the agility back.

TYTILIDIE said:
My TY has Sumitomo HTRZII 245/45/17-Front 285/35/18-rear
Wifes Ty has Sumitomo HTRZ 245/45/17-Front 315/35/17-rear
Click to expand...
They do look cool.

Here is what we are dealing with: The first reaction is to use suspension tuning techniques to loosen the chassis. While this can make the truck feel more predictable and fun, what we are doing is killing rear grip to make up for poor front grip. Now neither end will have optimum grip and it will become a sliding skate.

Treating the overkill front bias needs to be treated as the design flaw it is instead of manipulating the rear to behave equally as bad. The first thing to do is look at the alignment. Move to "0" negative camber and counter tire roll with more positive caster. The reason for this is more negative camber creates more 'dragging of the inside tire. We need that traction so finding the right balance to keep the inside tire flatter with the ground is key. Many of us already have too much caster as well. A 50 series tire with taller sidewall requires far more caster/neg camber than a 35 series tire to keep the tread flat with the ground. Many will notice too much caster as an uncertain feeling on turn-in. This is because too much caster has a "de-wedging" effect on the chassis where it unloads the outside front wheel
 
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