The Princess and the Pea...

[Blooze]

You've heard the story right?  The about the overly sensitive chick who could feel a pea through a dozen or so mattresses?  Yeah, that one.  Well I got to wonderin' if I was, or could be like that, with Forza - with the parts, with the tuning.  Such that the slightest little change was obvious to me - could I feel it?

This more or less all stems from a Factory Spec Event that I was running to improve my Career Time yesterday.  I was driving the stock NSX-R, and it occurred to me that the car really did handle well, and if allowed to tune it, what would I tune?  What would I change to make it better?   And if it handled this well with stock parts, what would the race type parts improve?  Would they improve it?

The more I mulled the this and the that the more I found that I really had no idea what a lot of those parts did.  Mostly, I would just blow through there, hit the right trigger so the selection would bounce to the far right and buy what was there without even looking.

And there is the other phenomenon that has been going on lately.  I am getting better with RWD cars - Finally.  It's only taken 3 years.  The balance of the car that I prefer has been moving toward the rear quite a bit, such that a 42% mid engined car is no problem.  In fact, I prefer it.

Lately I have been questioning my default "Tune It Lots Immediately" attitude.  I determined to examine the whole upgrade/tune scenario as closely as possible.  No part was going on my car without my knowing exactly what it brought to the table and what could be expected of it.

The Car:
The car I selected for the test was the Do-Luck NSX, cuz...

• I got lots of them, five to be exact.  Bimmer was cleaning out his garage one day and I "Luck"ed out. 
• I wanted to run in B - I'll discuss that in a bit.  The Do-Luck is about middle of the pack in B PI points starting out at 604.
• It is a Tuner - meaning it runs half way decent "as is".  I am planning on driving many miles with the car in stock or near stock trim and I would perfer not to tustling with the damned thing constantly.
• Also, because it is relatively stable in "stock" condition, the things I am wanting to test will less likely be masked by problem characteristics.
• And finally, I like the way it looks - including the paint job.

The Tracks:
I wanted a fixed regimine to test under.  I found that the B Class Professional Series event fit the bill.

• It has all three QR tracks in it at 7 or more laps.  The Infield Short race is also a ranking track.  Four out of five is not bad.
• I will be building my bank account as I do this - more than 150,000 CR for each pass through the series.
• With the AI set to easy, I can clear traffic before the first turn on all of the races which gives me at least 5 clean laps before I start having to deal with lapped traffic.
• There is a forced end and record keeping with a race.  In free run I sometimes run and run and run, thinking "This time..."
• Because the Event is a series, and because the race time is one of the measuring devices, there are no throw away laps.  Gotta stay up and on for the whole race.
• Miles Driven is not calculated in free run.  I want to get an idea of how many miles I invested in this test so running in an event solves that problem quite easily.  All I got to do is check the car's History when I'm done.

So, with the car in "Factory Spec" trim (I bought some Work Equip 03 rims for it )  I set my baseline.  The car QR's out at 202.7, it's total time for the five races is 2651.111.  Doing some arithmetic with the QR showed that the car would rank 487 (today) on the Overall B Class leaderboard.


Note: If you assemble a Numero Uno QR, you can calculate the percentage your QR is against the Number One QR.  Using this number, you can prognosticate fairly accurately times on all tracks and rollups on the leaderboards.  The Do-luck's QR was 90.3% of the top spot QR.  The times that I generated with the goal spreadsheet were within a tenth across the board.


Once I had set the base values, I went in to Free Run and set them again using 5 lap runs.  I was about 2 tenths faster on each track in Free Run, I think due to my being a bit more "comfortable" in there as opposed to in a race.  For my part, I figured that the race lap times would be close enough.

Okay, so there it is.  Ready for the first Pea...

$

[Fit4aking]

Looks like a lot of work there Blooze.  I remember when I started the TVR testing I ran them stock, then platformed, then with a specific class build non aero, then the same class with aero.  And those were before I even started to tune the cars.  It was overwhelming.  I hope to break it up by car model when I go back to it.  I look forward to your detailed accounts of each "pea".  I hope you find something, and I'm sure you will.

[Blooze]

And the first pea is...

The Race Flywheel

The text concerning the part speaks of increased throttle response and accelleration.  Smaller in diameter, lighter in weight, it allows the engine to rev up quicker.

Here is a link to one of the better articles I found on the subject today.
http://www.stockcarracing.com/techarticles/scrp_0610_reducing_moi/index.html

What I expected...
...was an engine that revved up quicker.  I expected faster accelleration through the power band.  I didn't know what to expect concerning engine braking - would the reduced MOI make engine braking less affective?

Buying the part cost me two PI points and shaved 11 pounds from the curb weight off the car.  It increased the accelleration calcs to the point that it's stat was bumped from 4.6 to 4.7.  In the benchmark, 0 to 60 was improved by .066, and 0 to 100 was improved .084.  In that the ET estimate, which was improved by the weight savings, only dropped .017, it appears that the change to the benchmark values is based on more than just the trimmed 11 pounds.  The drop in weight did garner a .01 drop in Gs @ 120 however.

What I got...
It wasn't a seat of the pants mind boggler, but there was a noticeable improvement.  I got clear of the traffic off the starting line faster, and I bumped into the rev limiter quite a bit in that first race, specially on the 2 to 3 change coming out of the double apex on Sebring Short.

• QR dropped from 202.700 to 202.144.  That's half a second for 2 PI Points.
• The total Race time dropped 20.193 seconds.

All in all, I am pretty well pleased with the part.  It acted like I expected, and the performance increase was fairly high considering the nominal cost.  Also, I will consider quite heavily the next time I get in a PI crunch and am looking for someplace to shave a point - the flywheel may not be the best option in that case.

The Next Pea...  The Race Clutch.

$

[DirtDriver]

Wow! I like this one, Blooze! Great concept.

DD

[gs shyner]

The race clutch and tranny, based on their stats, always seems like a no brainer, must have addition.
We're always shifting and if reduces shifting time as much as they post that's gotta be good for a couple o tenths to a second PER LAP.
Oh, I think I remember an example.  I believe I was running the C-Class? Nissan GT-R in the Professional series and when I upgraded the tranny and clutch, shifts became damn near instantaneous. More so than any other car I remembered.

I'm gonna be MOST interested in AERO.   To Aero or not and when / what class does it benefit.
Seems like, (based on race cars) that Aero is a necessity, but when does it "kick in".  
My gut tells me that Flowy Tracks will benefit from Aero but that Speed and Twisty's might do better without.

Currently I'm QR all D class sans aero and all cars I ran previously up to and including B class were without aero as well.
After I get some QR's beneath my belt, I'll try the Aero thing and run laps with Default/Lowest/Highest Aero values for comparison.

Any D/C/B class requests for a slowpoke?  

[bimmerlovere39]

Blooze - I may do something like this, too.  I'd probably use an E46 M3.

Are you going to take off the Flywheel before you put on the clutch?

[TheJohnNewton]

Two thoughts: 1) This is a pretty interesting read and 2) I'm glad you're doing it not me

[Blooze]

I haven't created an itenerary yet.  However, I do have a couple day list built up...

Flywheel	X
Clutch
Differential
Entire Drive Train

When it comes to the differential, I will be dealing with the 2 way vs. the 1.5 vs. no upgrade at all, more than all the baggage that comes with differential discussions.

As for Aero, I don't consider that a "Pea" and therefore will not be discussing that in this thread.

$

[Blooze]

Looks like a lot of work there Blooze.  I remember when I started the TVR testing I ran them stock, then platformed, then with a specific class build non aero, then the same class with aero.  And those were before I even started to tune the cars.  It was overwhelming.  I hope to break it up by car model when I go back to it.  I look forward to your detailed accounts of each "pea".  I hope you find something, and I'm sure you will.

I know what you mean - if you plot or plan even a little a monumental task seems to grow out the middle of it... 

I don't know that I am looking for a "something" so much as a clearer understanding of how the parts work with the car and each other.

$

[Blooze]

Wow! I like this one, Blooze! Great concept.

DD

LOL - grab a part and a wrench and jump in!

$

[Blooze]

Two thoughts: 1) This is a pretty interesting read and 2) I'm glad you're doing it not me

Glad you liked it.

My plan is to work a part a day - after that, I head to my recording studio and work on a song for my CD.

$

[Blooze]

So we spent a good part of the evening pulling the engine, removing the new flywheel and bolting our new Exedy triple plate racing clutch on.  Willis was a little bent about putting the old flywheel back on and made more than a few unkind comments concerning my OCD tendencies, not to mention my mother's heredity and the number of parents I had that were married to each other.  He gets like that sometimes.  Usually I toss him a bottle of Midol tablets that I bought as a joke once, and he takes the hint and shuts up.

The actual function of the clutch assembly has little to do with the game.  However, in the game, the Race clutch is good for .17 off the shift time and a 6 lb weight reduction.  Almost 2 tenths - no shift is required to get to 60 mph, but 2 shifts are needed to get to 100.  I sort of expected the 0-100 time to improve by .34 seconds plus the affect the 6 pounds would have on the MOI and curb weight of the car.

But I only got a .168 improvement in the 0-100, a little more than half the improvement I got with the 11 pound clutch.  The Estimated ET only improved .074 so once again, I gave consideration to the idea that they were factoring something besides weight when they calculated the accelleration time.

When I got to the track and ran then thing - the change became more significant.  This makes me wonder if they consider shift time in their benchmark calculations.

What I expected...
...was a push.  The improved shift time making up for the loss in accelleration due to the higher MOI.

What I got...
...was a subtantial increase in performance (see the table).  I guess the shift time improvement more than trumped the performance hit of the extra 5 pounds.

Configuration	PI	Quick Rank	Race Series
Baseline (Rims)	610	202.700	2651.111
DriveShaft Only	612	202.144	2630.918
Clutch Only	611	200.939	2618.245

***

This is interesting.  I find myself getting excited about the next step.  The upgrade is much more real.  "I put a new clutch in my rig last week and ya oughta see 'er run now."

From a RL perspective, it wouldn't happen like that, or not very often.  Most everybody would buy the clutch/flywheel as a unit and have them balanced together.  If for no other reason, you wouldn't want to have pull the engine twice.  Just once and git 'er done.  With that in mind, my next run will be with the Flywheel, Clutch, and Driveline bolted on.  We'll call it the MOI run...

Also, I was thinking that the Wheel Nut improving might be getting ready to rear its grizzled head so after the MOI run, I plan to pull all the parts and reset the baseline.  Don't tell Willis...

And ole Eph, he's been gatherin' all the stickers up from the parts boxes.   I think he is gonna stay late one of these nights and stick 'em on the car.  The Exedy people were out at the track last week handin' out checks - we might as well try to cash in on some of it.

So far I've driven 211 miles and made 490,000 Cr on this project.

$

[bimmerlovere39]

490,000 for learning - not bad, not bad at all!

Looks good, Blooze.  I'm following this.

[Blooze]

Got a project for ya Bimmer, if you want it - or for anybody that wants to do it for that matter.

I am curious to see if these parts inflict a particular change on the times or if it is just a factor of the weight saved.  So...

Get yourself the B car of your choice and then...

• Run the B Class Pro Series for a Baseline.  The car should be stone stock, or the tires adjusted.  Note, if you set the tires, leave 'em that way for the balance of the test.
• Now add the Flywheel, Clutch, and Driveline.  Take note of the weight savings.  Run the series again.
• Next, remove the parts, and go find the rim set that comes the closest to the same weight as the three parts.  And run the series again.

Hopefully we will be able to prove that 22 lbs worth of parts is better than 22 lbs of wheels.

$

[bimmerlovere39]

I think I can do that!