CodyBigdog

Not saying the 60-130 time metric isn’t valid, or that is doesn’t illustrate what it can do at the higher speeds, but, I will, for the most part, never be in a position on the street near me (track is different), to safely ever get much above 100 mph, let alone 130. However, 30-70 or 40-80 times are very useful, in highway merging and overtaking situations. Of all the time metrics, these are the speeds I will use more often…in REAL WORLD situations.

The 1/8 mile @103 mph is about as fast as I will occasionally get. The road I had been running times on, was a -more or less - deserted road near our local airport. Nobody uses. 1/8 mi was no swet. 1/4 mi I ran out of room before the road began to slope, and became invalid.

Oh, and the much maligned, or dismissed 0-60 times is still quite relevant to me in my daily driving. Can’t tell you how many times I’m sitting at a red light, in the left most lane, with cars stacked up behind me in both lanes. My wife says, “you’re gonna miss the turn…you need to get over” which is coming up on the right in a few hundred feet, or so. In cases like this, yeah, off the line acceleration, 0-60 times do matter to me.

SBAD

I get you CodyBigdog. Nothing like a scientific mind to put a damper on the emotional feel good party. I completely understand where you are coming from and yes - any tuner should publish actual performance figures of before and after with their tune. Its business 101.

The themes here remind of the vax versus anti-vax debate. I'm waiting for it to get political with someone starting the ad-hominem attacks.

I too am on the sidelines, anticipating some legit performance numbers before dropping down $2.4K.

CodyBigdog

Thank you. What’s funny to me is - I have only been asking for quantifiable results on any number of metrics…0-60mph is just one of those metrics (PS - I did NOT start this thread). This should be a no-brainer to ask for times…either from the manufacturer, or the customers who bought their product. Instead of people saying they agree, I get a bunch of BS why this, or that metric doesn’t matter, etc, etc.

I’m one of those posters who doesn’t believe nor care about half the crap on Rennlist. Unless the poster knows something I don’t, and can prove it, they are wasting their time by trying to convince me their opinions matter to me. They don’t. I first learned to ignore Rennlist opinions when I was building my Porsche, about a year ago. I remember a number of people saying, “don’t waste your money on FAL, you wont need it”. They don’t know me, or where I live….yet, they are so delusional with their own opinions, to think they know what’s best for me. . Turns out, I needed it. I measured on a test 911 without FAL.

Cheers. 👍

Tupper

You are not the only scientific mind on Rennlist.

It’s not wrong to ask, but I think you are focused on a question that doesn’t really require answering.

When we have dyno results showing a major bump in HP and torque, and a couple of us reporting our real life datalogs showing a dramatic increase in boost compared to stock, then one can infer that the car is only going to be faster.

You spend a lot of time on Rennlist arguing with strangers so I doubt your claim that you could care less what people here think.

If you want a scientific analysis that remains unanswered, it was my effort a few months ago to gather up data whether headers and aftermarket exhausts increase power. I got crickets and a few angry responses, but nobody produced anything until I dug around on the Internet and posted real life videos of those exact mods with before/after dyno pulls and how they impact power on this very forum.

But the tunes? We don’t have a lot of dragy times, but we have pretty good proxy’s for them.

CodyBigdog

.

LOL, of course it’s NOT wrong to ask. I won’t assume who, or how many scientific minds are on Rennlist? I have no data. But again, its only your opinion that it’s a question that “doesn’t really require answering”. Nevertheless, you already have the tune, and never bothered to ask..so clearly, it’s of no importance to you. That’s fine for you. But not all of us.



Well, one poster with the tune showed no significant time improvement on two different metrics. But yes, I would agree that it’s just common sense to assume more power/torque translates to quicker times…but how much quicker, and for which metrics…those are the questions? Apparently, not for 0-60?

I argue (discuss) with people that either mis-quote me, present wrong information, or, only present an opinion, rather than facts on the question being asked - how much quicker? Not how much boost, or HP.

Good for you, and i must have missed this thread buried amongst the endless number of opinion threads. What was the title of your thread and i will check it out. Always interested in factual information.

As I mentioned, times may not be of interest to you or other folk…but I’m pretty sure there are people that are interested. As such, I’m most surprised that the companies involved with automotive performance enhancements, don’t post the before and after results. I would, if that was my company. In fact, when I was in the business of selling expensive, high tech gear to DoD, etc…I would always have a glossy spec sheet that I handed out, that showed our results, compared to our competitors. Power point briefing only go so far…but a hard copy showing why my product is better, usually helps clinch the deal.

Oh, and there could be many reasons why the company doesn’t list times, including it’s just not important to them. Or, maybe, just maybe, the time improvements may only apply to a few metrics, and not others…and therefore, not really a strong selling point?

reddsektor

The tuners should try to post 0-60 and 1/4 mile times I agree, but when you're talking about specific real world ranges like 30-70 or 40-80, almost no one on here or any car forum in general is going to care to specifically set those custom intervals up on a dragy and do runs to measure. 60-130 (or 100-200kmh) is a defined metric on there however.


Fwiw, my only 0-60 run post tune was 3.3 (not including 1ft rollout) on un-prepped almost worn pirelli's that spun thru 2nd. When I get my PS4S, I'm sure it'll be slightly better. But maybe not significantly since its still a lot of power for rwd to put down, and thus not a good representation of the tune's potential or power. I will still do it for "science".

I will say this, a local guy I know in DFW got 2.83 with 1ft rollout.

1/4 mile times have been posted in the M-eng thread, ranging in the upper 10's.
-And a quote from that same local person on this: "Stock 1/4 mile went from 11.33 at 124ish mph to 10.74 at 128ish mph (although on that run, the graph shows that I lifted just prior to the end of the 1/4 mile so ET and MPH would be just a fraction better had I not lifted)."

I actually posted these times early on in the M-eng thread when they released their tune, so the data has been there if people read it.

CodyBigdog

I understand, but they are relevant to me, and easy enough to set up on Dragy.

60, 1/8mi and 1/4 mi times are fine.



Did you try getting the tires warm before the pulls? I drive hard at highway speeds for at least 30 minutes before I try a run.

I appreciate you posting your times. Others may not be interested, but I am.

That is closer to what I expected.

I’ll check that out, thx.



Any improvement of > than 0.5 sec is significant, in my book.

I’ve followed some of the m-engineering threads, but not all of them. I will look for the one you mention. Thx

Tupper

@reddsektor are you an S or a base Carrera?

Also, 93 or 91 octane and are you Stage 1 or 2?

Lots of variables at play here.

RoughRider911

This is more along the lines of what I expected. I checked tire pressures and the rears are at 48. I’m going to drop the tires to the comfort level (29/32), drive for 30 min on the highway and try again. Traction has gotten worse with the tune so I think these adjustments will help get the times under the 3 sec mark.

reddsektor

2020 C2S pdk on 93 octane stg2, catless downpipes, PSE, and performance filters.

The person who’s times I was referring to also has the same car but on stg1 (stock cats with FI exhaust and BMS filters).

reddsektor

No problem mate and happy to share!

I had only driven the car for about 5-10 mins locally before trying the run about a couple months ago on a good road. I've kind of given up on the pirellis since their time is coming so hopefully can get PS4S in a few months and really rip some numbers, albeit in the summer heat.

CodyBigdog

Wise choice. That will be my next tire when my PZero wears out.

One of my buddies that tracks every week during the warm months, instructed me how critically important getting your tires properly prepped prior to any runs.

CodyBigdog

Interesting article: https://www.motortrend.com/how-to/ct...on-principles/

If traction is your problem, with the extra HP, Ask two 200lbs buddies to squeeze into the back seats. 👍

Tires Are The Key
It has been said many times before by most authors of racing technology that everything we do related to chassis setup comes down to making the tires work harder. Tires are the ultimate connection between the car and the racing surface. Far more racers have been disqualified for illegal tires than any other infringement. It's because improvement to grip represents the most gain in performance.

The concept of tire performance is always at the forefront when trying to understand ways to improve the overall performance in our race car. It is again at the very top of the list when we discuss traction. Listed here are seven areas of influence that directly affect the amount of traction that a set of dirt or asphalt tires will develop:

Vertical Loading
Increasing the amount of vertical loading (weight) on the tire increases traction, but in a non-linear way. That is to say that as we increase loading on a tire, it will gain traction, but not in exact multiples. If a tire has "X" amount of traction with 400 pounds on it, the traction will be less than double as we apply 800 pounds of loading to it. The amount of traction will be less than 2 times X.

Contact Patch
The size and cross sectional loading of the contact patch helps determine how much traction we will have for a particular tire. An added effect related to the contact patch and traction involves grooving and siping with dirt tires and will be discussed later on.

Reducing the air pressure will usually increase the size of the tire contract patch which would seem to enhance traction, but excessively low or high pressures may reduce the loading on portions of the tire so that the total loading of the tire is reduced and we end up with less available traction for that tire. There is an optimum operating air pressure for each tire that will offer maximum contact patch area and equal loading across the width of the patch.

Camber also affects the size and cross sectional loading of the contact patch. The correct camber angle compensates for the deflection of the tire sidewalls as the lateral force is applied when we turn the car. More or less camber than what would be ideal means that one side of the tire will support more load than the other and this also reduces traction.

CodyBigdog

https://www.motortrend.com/news/how-...reet-wheelies/

Considering that Reid works at Late Model Racecraft, a shop where 1,000-plus horsepower street cars and 6-second drag-radial cars are the norm, we were a bit skeptical about how effectively a street surface could harness such extreme horsepower. Naturally, we had to ask how someone goes about prepping a public street for maximum straightline grip. "Some people just use Dr. Pepper. Pour some down, do a burnout it in, and you're good to go," Reid reports. A bit incredulous, we probe further to see if it's really that easy. "Well, there's more to it than that. PJ1 Track Bite is the best traction compound out there. We do practice launches behind our shop all the time. One of our guys pulled a huge wheelie the other day."

😳

rob.james.arias

2020 C4s, extremely low tread Goodyear Eagle tires. Apr 93 Octane Stage 1. New tires go on this week and I am highly confident I can get this number down further.