GREGGPENN

I'm from the C4 section and am doing an engine build. Of the two intakes I have to use, one is an HSR that's VERY similar to the LS7 powerband. The other is a modified intake (SLP) that's very similar to a superram (which builds even more mid-range torque by trading some high-end power).

Below, you will see a chart of the projected crankshaft torque levels of my two options (with accessories).

Gear-RPMs-MPH---SLP-TQ--HSR-TQ
2nd- 1600 20mph 276ft/lbs 278ft/lbs
2nd- 2200 27mph 333ft/lbs 311ft/lbs
2nd- 2800 35mph 430ft/lbs 382ft/lbs
2nd- 3400 42mph 477ft/lbs 412ft/lbs
2nd- 4000 50mph 487ft/lbs 438ft/lbs
2nd- 4600 57mph 472ft/lbs 457ft/lbs
2nd- 5200 64mph 421ft/lbs 455ft/lbs

3rd- 2200 38mph 333ft/lbs 311ft/lbs
3rd- 2800 48mph 430ft/lbs 382ft/lbs
3rd- 3400 59mph 477ft/lbs 412ft/lbs
3rd- 4000 60mph 487ft/lbs 438ft/lbs
3rd- 4600 79mph 472ft/lbs 457ft/lbs
3rd- 5200 90mph 421ft/lbs 455ft/lbs

First and foremost, you need to know I'm building a street car -- with no intention of racing. Additionally, I'm 52yrs old and fairly set in the way I'll drive the car.

Because the car will have SO much power, I just might short-shift 1st ALOT. Coming out of turns in the city will be done in 2nd gear. Power levels and mph can be seen above (for 2nd gear). On the hwy, I'm more likely to stay in 3rd gear (or higher). It's for these two situations that I'm analyzing the result.

Because the SLPs torque capability would actually exceed an LS7 for a narrow mid-range powerband, I want/need to know if I'd have trouble with traction. Since an LS7's torque levels fall between the two options above, I want to know about hookability -- to make my final choice of intake. (IOW, if this post were one question, I'd ask if you'd want more torque! LOL).

The following question is the main point of this thread!
If you do a rolling start from 25mph in 2nd gear, fully engage the clutch -- then hit the gas, will the tires hold? (Revving and dumping is NOT what I'm asking about). What if you start at 30mph or 35?

For a rolling start in 3rd gear above 45mph, I'm sure it'd hold, so I won't bother to ask about that.

This thread is my attempt to figure out at what torque value traction becomes a significant problem -- especially in 2nd gear. And, I'm not asking how hard it is to break it loose, I'm asking how hard is it to get to hook -- even when you try to hook it.

Get it?

Thanks for your help!

Gregg

Flareside

Unless it's cold out, I don't really have any traction issues with my Z in 2nd at low speed. You have to be careful in 1st of course, but 2nd is fine.

In reality, most of the tire spinning on a Z happens at RPM levels that aren't even on your chart. We are just getting started at 5200... Torque at a low rpm isn't the same as torque across a wide range, especially when it comes to traction. Your car will also be heavier and probably have smaller tires. Basically, apples and oranges.

Oh, and every Z is M6.