<<<ran the turbo ka-13.077 at 108.17 mph>>

Post by **14.5drift** » Mon Jan 26, 2004 8:42 pm

I thought supra's did fine. Never heard of this http://www.titanmotorsports.com/900160mph.html

Post by **02_silver_wagon** » Mon Jan 26, 2004 8:42 pm

What CR are you pistons? Not to be rude or anything but I am looking at a similar setup and I thought a KA@17psi on a T04E 60 Trim would have more than 310 rwhp and 316 ft/lbs of torque. I am looking at the Precision SC60 60 Trim .63 A/R Stage 3 wheel, turbine side. What do you guys think for full spool by 3500-3800 and 350whp@15psi with 9.0(or a little higher) compression ratio? Its rated at 580hp.

Post by **klattr1** » Mon Jan 26, 2004 8:42 pm

02_silver_wagon wrote:What CR are you pistons? Not to be rude or anything but I am looking at a similar setup and I thought a KA@17psi on a T04E 60 Trim would have more than 310 rwhp and 316 ft/lbs of torque. I am looking at the Precision SC60 60 Trim .63 A/R Stage 3 wheel, turbine side. What do you guys think for full spool by 3500-3800 and 350whp@15psi with 9.0(or a little higher) compression ratio? Its rated at 580hp.

I have 8.5:1 compression. I'm not sure why I'm getting a big difference in numbers compared to most turbo ka people that run past 15 psi with a t04e compressor. My plan of attack is to check compression of each cylinder and then I will go from there. I also have a used turbo but I wouldnt know if turbo's can just stop flowing as much air over time. Anyone know?I'm thinking of going with a bigger turbo this summer. Prolly a Precision SC61.

Post by **02_silver_wagon** » Mon Jan 26, 2004 8:42 pm

I was recommended the SC61, but I don't want the lag it would have. Probably 4000-4200rpm. I'm trying to build a descent autox car. That is why I want the low lag. Speaking of lag what rpm do you hit full boost?

Post by **klattr1** » Mon Jan 26, 2004 8:42 pm

somewhere around 3600 rpm

Post by **JPRempe** » Mon Jan 26, 2004 8:42 pm

Phax wrote:315's?!? I know single turbo Supra guys who aren't even running rear tires that wide. What's the point of going for such a huge contact patch?

The tire contact patch area (or as you describe it, size) does not go up or down when switching to wider or narrower wheels/tires. Wheel contact patch size is determined by a combination of vehicle weight and weight distribution. What it does is change the shape of the patch (while still maintaining the same overall area).

For example (I'm using a 1994 Mazda Miata as the vehicle), a 215/45-16 tire has a contact patch of 19.64 inches squared. A 185/60-14 tire has the exact same area of 19.64 inches squared. Changing width only changes the orientation of the contact patch...NOT IT'S SIZE !

Post by **andrave** » Mon Jan 26, 2004 8:42 pm

I don't understand how that could be, since its obviously a wider area contacting the pavement.

Post by **JPRempe** » Mon Jan 26, 2004 8:42 pm

andrave wrote:I don't understand how that could be, since its obviously a wider area contacting the pavement.

Like I stated, it does not change the overall size, but changes the orientation of the patch on the pavement. On a narrower tire, the contact patch is more square, but on a wider tire, the contact patch is wider and thinner. You will not gain patch size unless you change weight bias/distribution or overall vehicle weight.

EDIT- Here's a quick drawing to give you an idea...

I didn't sit down and draw it perfectly correct, but you get the general idea.

Post by **andrave** » Mon Jan 26, 2004 8:42 pm

I'd think those would be backwards. perhaps this is obvious to others but I'm dumbfounded. Or just dumb. lol

Website · Post by **TurboKA37** » Mon Jan 26, 2004 8:42 pm

thats what i thought at first also but you are looking at it the wrong way. the black part is the contact patch and white part is the rest of the tire and the view is from directly underneath the tire. think of the tires in the picture he made as rolling to either the right or left

Post by **90lkn4swp** » Mon Jan 26, 2004 8:42 pm

Your also comparing 16's to 14's. Wouldnt the 14 already have a smaller contact patch? Also if you used 185/60-16's wouldnt that increase the area?

Post by **90lkn4swp** » Mon Jan 26, 2004 8:42 pm

I just realized i know nothing about tire sizes and it would no longer be 185 if it was a 16 inch tire. Or is it 14 and 16 the inside size of the tire to the wheel, and the 185 and 215 the outer circumfrence? Nevermind i have no idea what im talking about.

Post by **90lkn4swp** » Mon Jan 26, 2004 8:42 pm

**** sorry for the hijack

Post by **Nathan** » Mon Jan 26, 2004 8:42 pm

JPRempe wrote:The tire contact patch area does not go up or down when switching to wider or narrower wheels/tires Changing width only changes the orientation of the contact patch...NOT IT'S SIZE !

Thank you! I've tried to explain it before but finally gave up. It's just a property of something that is inflated that the only way you can change it's contact patch (at a given weight placed upon it) is to lower the air pressure in it.

Post by **Structure240sx** » Mon Jan 26, 2004 8:42 pm

so if i get 225's of the same tire i would jsut as much traction as my 255's?

Post by **JPRempe** » Mon Jan 26, 2004 8:42 pm

Structure240sx wrote:so if i get 225's of the same tire i would jsut as much traction as my 255's?

That depends. With wider tires, you'd have more starting off the line traction (or idle-2000 RPM traction), but it won't last for long becuase the patch isn't very deep. When you'd go into boost you might or probably would break loose. If you had a narrower patch (narrower tire) that was deeper, you'd probably be able to maintain better traction for longer, but wouldn't be able to get off the line as fast.

Post by **Structure240sx** » Mon Jan 26, 2004 8:42 pm

so like always you have to comprimise

<<<ran the turbo ka-13.077 at 108.17 mph>>

hey

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