FM4 Friday Night Race - Month of August: Nissan 370Z Tuning Workshop (CLOSED)

[Nunzie]

After I add the upgrades as listed and all the body panels ( front and rear bumpers, side skirts and rear wing) I end up with a 533pi. But that is with stock rims. To drop down to a 532pi, I will need to add a heavier rim. Does this sound correct?

[GRD 4 3L]

I've ended up with 522 in my car but that's using stock tires.  533 is still alright.  +/- couple PI's is not going to make a large difference.

Go ahead and use it.  I'm going to update the 1st post so the max. limit is 535 including the rims.

[Nunzie]

Ran a few laps to get 1:26.4 run with tires at 29/29. Felt ok, but hard to correct if I messed up a line (a do this a lot ).

Tried 32/32 and got 1:26.29. Not much better lap time, but I felt a had more control over the turn-in accuracy and could now correct when I miss a line.

This car has a nice balance point and is easy to control in a four-wheel drift.

[GRD 4 3L]

Yeah, I think when the pressure is low the tire flexes too much leading to wobbly/floaty feel to it.  If the pressure is increased the car feels more responsive BUT more slippery as well.

[Nunzie]

So here is a question:

Is there an optimal tire temp?

If so, does the optimal tire temp change depending on the tire type ( sport vs race) due to the tire compounds?

Is it easier to adjust by watching the color? I assumed dark green was the best.

[GRD 4 3L]

So here is a question:

Is there an optimal tire temp?

If so, does the optimal tire temp change depending on the tire type ( sport vs race) due to the tire compounds?

Is it easier to adjust by watching the color? I assumed dark green was the best.

That's more than a question!

There is an optimal tire temp but I have not tried other tire types.  I am seeing 180~200 as darkest green for the stock tires (street tires).  You can tell me what your green band temperature range is.

Watching the colour is alright but since we are only adjusting pressure (not camber), I used the Tires, Misc. screen which shows average temperature and pressure at the same time.

I think pressure dictates how the tire behaves and temperature increase seems to be not too dependent on the pressure.  I tried about 27psi, 32 psi, and 37 psi and they all seem to get up to the temperature about the same rate and top out at about 190 deg F, occasionally going higher if driven too aggressively.  If driven with minimal wheel spin and lock up, the temp stays about 190F or lower.

If you start locking up the tires or spin the rear wheel, then the temperature climbs very rapidly and may affect the grip until the rubber returns back to about 190 deg F.

I have settled at 35/35 instead of 32/30.  My reasoning (VERY EASY to tune for max grip) is rather silly but accurate and ANYONE can tune tire pressure using this method.  I will reveal the method during our trial session tomorrow.  As proof, I have a new clean lap of 1:23.082, which is 0.106 seconds faster than my previous fast lap.  It had a potential for 1:22.9 but I buggered it up at the last corner onto the straight and I got it on lap #4 (need minimum of 3 laps for tires temps to stabilize).

Another 25 laps completed today . . . that brings total to about 80 trial laps I think . . .

Now I know this track and this car very well.  This feel for the track/car will serve well as the baseline for the next week's upgrade.

[derekthetree]

I did some lapping this afternoon.

1st tried out 32/32, as per some of the suggestions above. The car felt very light on it wheels, I didn't feel confident applying the power after the apex.
I managed to get a 1:25.240.

Then I reverted to my usual tune of 29/29 (I don't do much tyre pressure tuning so this is my stock setup for F through to R1!)
With this setting the car felt a little slower to respond, but I felt so much more confident with the throttle. The seemed much more stable and I could go faster through the faster corners (see below). A few laps and I was down to 1:24.9 with some more 10ths to chase.

Overall with some more time and practice a higher pressure would result in a faster time but I think the faster, crested turns on catalunya (3rd especially) suit my "softer" pressure settings

[GRD 4 3L]

I also felt the same and lingered in the lower 30's and high 20's because I could see the car against the ghost performance.  Lower pressure 'feels' like it has more grip but does it really?

My hypothesis (whether right or wrong), at lower pressure, the tire deflects more therefore the 'soft' feel comes from the tire walls absorbing the momentum of the car until a limit.  When that limit is reached, the traction gently gives way leading to 'grip' feel.  At higher pressure, the 'soft' feel is diminished and the tire gives more suddenly therefore the feel of 'looseness'.

I also thought that high 20's would be best given the feel.  However, after few laps at 35psi the lap times were more consistent, the grip was more consistent, and car reaction was quicker.  In addition to that, braking was easier and corner exits were also smoother.  It is counter intuitive but there is a CLEAR & HARD feedback from FM4 that tells you where the most grip is.  I have only tried it on 370Z so far therefore the method cannot be deemed robust but it clearly is an indicator of good performance.

At the end, it always comes down to personal preference.

A good read but still does NOT explain how to arrive at optimal tire pressures.
http://www.supercheats.com/guides/forza-motorsport-4/advanced-tuning-guide

[GRD 4 3L]

Supernovadave is so fast no matter what track and car!

Thanks D Seeeker & SROTH for showing up! 

Races Completed
370Z - Catalunya National, 10 laps, Supernovadave
370Z - Sunset GP, 12 laps, Supernovadave
111s - Catalunya GP, 5 laps, GRD43L
111s - Mugello, 5 laps, GRD43L
F Class - Road Atlanta Club, 5 laps, D Seeker34

[GRD 4 3L]

I've tried the Sports tires vs. stock tires and there's virtually no difference in my opinion.

Therefore Race Tires will be permitted for use from next event.

I've also tested Race Brakes & Race Differential.  While Race Brakes are much more stable and effective in slowing the car down, it did not affect the lap time noticeably.  Race Differential, however, allows the car to turn in better and exit more cleanly.  It is worth about 0.5s per lap (1:22.6 in Testing mode, and 1:22.9 in Hot Lap).

I'm using 48% front for brakes; 50% was theoretically best but I wanted the rear to help turn in during heavy braking.  More playing around needed.

For Race Differential, 70/10 is my setting.  Did not feel a significant difference in brake settings until it was lowered to zero.  So instead of zero, made it 10 for now.  For acceleration, I really could not feel the difference at either at 0 or 100; would probably have to do many laps to sort it out, if possible.

[derekthetree]

Cheers for the awesome decal GRD.

Here is my paintjob for this series

[GRD 4 3L]

I see that you've got a "Two Face" thing going there . . .

Here's mine in action:


And video, which is more exciting:
[embed=425,349]http://youtu.be/5V9tF_MIkCY[/embed]

The video was taken during a race at Swiss Alps track.  This track is good for evaluating deceleration differential setting because it has so many high speed turns where the rear wants to step out.

[GRD 4 3L]

At Catalunya National track, addition of Racing Brake & Differential did not make a noticeable change.  It improves the braking a bit (feels 'better'?!?) but I had to adjust the differential by testing at Bernese Alps.

I guess we will go through this week as is then look forward to next week's Racing ARBs!

[GRD 4 3L]

Well, it's been a bummer of a race night with my 360 on the verge of a meltdown and all . . .

My 360 has been acting up lately with 2 red ring of death.  It works fine but just cannot do long/hard stints anymore.  It will still play lighter fares such as Netflix, Minecraft, etc. but my son has issues playing COD, I could not play Ferrari Racing Legends, and now Forza on-line.

I don't know when I'll get my 360 replaced but until then, consider myself out of on-line play . . .

[D Seeker34]

Yea that was a drag you losing your connection and having to bail. With an already minimal field we had to call it a night as well. More racers are needed for these competitions not sure why we had a big drop off lately but new blood or the return of old blood is needed.

I'm working on a NASCAR Sprint Cup style race format that I am hoping can be a combination of live and hot lap style competition to make it easier for people to participate that can't make a race night regularly.