S14 Race Car Build + Tuning Thread

[Sasha_SG]

Saw buddies project 240 thread and figured we needed more threads like this. There arent many heavy tech threads on SON, ive been on Honda-Tech lately and its just absolutly AMAZING.

Ok so lets start with what the car has so far starting from the beggining of this season (of course everything with pics)

First Mosport Race Fastest Lap: 1.35.457 first time at Mosport
Power: 12psi On HKS GT-RS = 280whp
Aero: Small rear wing, GP sports front bumper
Alignment: Poor front Camber, no real alignment
Weight: 2750lbs Race Weight

Second Mosport Race Fastest Lap: 1.34.536
Power: 280whp
Aero: Nascar style ugly spoiler, GP sports front bumper
Alignment: Poor front Camber, no real alignment
Weight: 2810lbs Race Weight (more fuel + rewards weight from prev races)

Third Mosport Race Fastest Lap: 1.35.305
Power: 270whp - down on power new turbo only @ 10psi
Aero: Nascar spoiler, Ugly Verion Select Front Bumper, Flapping hood
Alignment: Good Front Camber, still no real alignment
Weight: 2980lbs Race Weight (put too much extra weight in the car)

Fourth Mosport Race Fastest Lap: 1.32.707
Power: 270whp - still only at 10psi
Aero: APR GTC-300wing and HUGE splitter on version select aero with taped front bumper
Alignment: Proper alignment with good camber and toe all around
Weight: 2920lbs Race Weight (still too much weight in the car)

Fifth Mosport Race Fastest Lap: 1.31.351 * pushing HARD
Power: 270whp - 10psi AGAIN
Aero: APR GTC-300wing and splitter cut down to 1.5" but added diveplanes to bumper, no longer taped bumper.
Alignment: NEW tie rods - no more slack, car actually TURNS hard.
Weight: 2780lbs Race weight (made a huge diff)

Sixth Mosport Race Fastest Lap: 1.30.937 *pushing HARD
Power: 305whp - 12psi VERY cold day, car was FAST
Aero: APR GTC-300 wing, 1.5" splitter and diveplanes (trimmed smaller for rules)
Alignment: Same as above
Weight: 2810lbs Race Weight

So that should give you all an idea of where improvements were found. The biggest improvements (other than driving improvement over time obviously) were found with DOWNFORCE and WEIGHT.

So naturally for next season im trying to get more DOWNFORCE with less WEIGHT! Throughout the season i removed over 200lbs from the car, but due to mandated weights for the season I had to just add 200lbs of balast to the car (although i was able to move it around to help the car turn). My goal for next season is a 2300lb race weight, with some underbody aerodynamic work hoping to get into the 28s. Maybe a dip into the 27s. On RA-1s.

Some observations:

After adding the splitter and wing I was able to enter corners 1 and 2 of Mosport with no brakes what so ever, and take corner 4 without fully lifting, almost full throttle one time when the tires were in their prime.

After removing the nascar style spoiler and putting on the wing my straightaway speeds were exactly the same, even though my downforce was increased ridiculously. Nascar = terrible!

Downforce is one of the most amazing feelings you will ever experience, esspecially if it is balanced correctly.

My STEADY (like the car is on the limit mid corner) cornering speeds in corner 8 went from 138km/h (speedo - actually higher due to tire size) to over 150km/h throughout the course of the season. This is atributed to all the tuning i had done to the car over the season, proving that every little bit counts, and it all adds up to BIG numbers (as you can see by shaving 5 seconds)

Had I not changed the aerodynamics and kept the weight the same throughout the season, the car would have most likely been able to do a mid 1.32.

More to come boys, including fabrication to improve chassis stiffness, engine problems i had throughout the season and how I will address them, alignment talk and setup, drivetrain setup and gearingi for Mosport, underbody aerodynamics, finding weight to remove, body working, painless wiring install - removing factory wiring, lexan window installation etc.

[s13Junkyard]

good read

thx

[Gonad]

What kind of tires (and wear on them) were you running?

I’m sure they contribute a lot to your improvement through the various stages?

[Theo23]

Have you ever pushed it too far beyond its limits going through a corner on that track and could you tell us about that experience?

Mistakes are the key to knowlege.

Good thread! Will be educational I’m sure!

Theo

[Sasha_SG]

G - Tires in the series are a mandated Toyo RA1. I’ve been told going from RA1’s to slicks yeild between 2-3 seconds a lap.

My tire sizes are

275/35/18R - Front
305/35/18R - Rear

Right now I start to get too much heat into my front tires and when the rears get fully up to temp the car develops a bit of a push, so for next season i’m going to try some things to keep it neutral once the tires are up to temp all around. Before the rears heat up though (and they take a while since they are so big) the car is VERY loose. And being sideways at 200km/h isn’t the most comfortable thing.

Tires used are throw aways from Speed World Challenge guys, at the past Mosport SWC race I picked up 18 tires, 8 rears and 10 fronts. Tire life depends on how much tire is left when they are mounted, but generally a good tire will last me 1.5-2ish weekends for the front, and 2-3 weekends for the rears. However the more I use a tire the slower the car gets - theres a reason the Speed WC guys throw their tires out!

Theo - Heres a track layout from mosport:

The key corners at mosport are 2 and 4. Those are the famous blind apex corners that everyone talks about, 2 is regarded as the scariest most challenging corner in North America, however i think thats a bit overrated, but it is pretty crazy!

One or two times i’ve entered 2 too fast and trail braked, causing a BIGGG slide. Had I not caught the slide, or god forbid had I tank slapped my car would have been damaged bad, if not written off. If you slide off at the top of 2 you’re going on a ride over some slick grass and into a tire barrier. Since you cant see the Apex its a really hard to judge your brake and turn in point, but once you get corner 2 you realize its actually pretty easy. It just takes some time.

Corner 9 is also easy to overdrive, entering from 8 with so much speed, and corner 9 always seems to have a bit less grip than youd think it should have. I’ve slid that corner a few times too.

Basically, when I know im overdriving a corner I trail brake to scrub speed and that results in the car getting really sideways (as it would with just about any car). The car slides and slows itself down and I actually dont end up losing too much time at all.

You can get loose on entry to corner 5 too if you exit 4 too wide and dont get to brake in a straight line, here I got loose on entery, which became a slide over the crest, and I gave her full throttle for the hell of it to try and round 5a and 5b. I almost had enough power to do it

As the season went on these slides were less and less frequent, as I became more consistent, even though I was pushing that much harder. The way I look at driver consistency is as a percentage zone. Lets say I started the season with a 10% inconsistency average. That means if im pushing 9/10ths I might hit a corner 10/10ths (by accident) by misjuding the corner, or I might enter way too slow at only 8/10ths. Basically the 10% inconistency zone means that you can push at 9/10ths of your ability safely, without the chance of messing up huge.

I kept this in mind throughout the season, and by the last 2-3 events I was able to push 10/10ths without any concequence. I was pushing myself at my absolute limit, and thats when the last few tenths came off my times. I would say I am now at around a 2-2.5% inconsistency zone for Mosport, and more for a car or track that I am unfamillier with. As I learn more tracks, improve as a driver, and experience more cars I hope that I can close this inconsitency zone even more, esspecially when experimenting with vehicles ive never driven or learning tracks ive never tried. It’s just a way to put into perspective my consistency, since being fast doesnt matter at all unless you can do it all the time!

Had I pushed 10/10ths my first time out, I would have FOR SURE gotten myself into a situation I couldn’t have saved (by ending in an 11/10 situation) and that would have been plain stupid. Thats the sort of thing where you get banned from the CASC for a year because you are driving DANGEROUSLY and well beyond your means.

A lot of guys starting out with drifting have trouble with this. Since a good drift can really only occur in your top 9.5-10/10, we have guys with a 10-20% inconsitency zone flying off the course half the time, or entering way too slow because they haven’t gotten themselves consistent enough with their car and the track they are on to lay down consistent drifts. We need to figure out a way to help guys get more consistent before they start trying big drifts!

That being said, a consistent drifter will be able to pickup lapping well for the very same reasons.

[Happy240sx]

Love this thread Sasha - keep going.

Please also add in your race recaps how/where you finished in the field

[snowboard_240sx]

man this is awesome

best thread ever!

[Gonad]

Perhaps your tire’s lifespan is due to lack of alignment?

I’m curiuos as to why you haven’t gotten that done?

Also, do you have any in car footage?

But yea, I would definitely love to come out next year to see you run.

[Sasha_SG]

My alignment seemed pretty close and the stock components have very little to no adjustability so I didn’t bother towing my car to the alignment shop then towing it back just to set the front toe. After I installed full rear multi-link I got a good alignment and set everything up as I wanted. Then the alignment dude and I realize how messed up the tie rods are, they are on the verge of falling apart entirely. For the next race I got SPL tie rods with 300ZX inner and a new alignment - MAN did the car ever turn after that. It was incredible. The wheels must have had way too much play before and were just wobbling around like crazy, not biting the road nicely, causing the car to push a lot.

I don’t have any incar footage but heres a small clip of a few different corners, 4 up into 5, coming through 3 and leaving 5

http://www.sequence-garage.com/mosport.wmv (8MB)

I’ll just quickly post how I finished (there are often 2 races per weekend)

Legend:

• Mechanical DNF
  ** Mechanical Causing Car To Be Really Slow And Lose Position
  *** Disqualified
  FL Fastest Lap In Class
  FLO Fastest Lap Overall

Race 1 @ Mosport:
Qualified: 3rd
R1: 4th** (overheating) FL
R2: 3rd** (overheating again - not enough ducting)

Race 2 @ Shannonville:
Qualified: 1st
R1 (1hr): 3rd** (rear brake caliper seal - lost all pedal pressure!)

Race 3 @ Mosport:
Qualified: 1st
R1 (85min): 1st

Race 4 @ Shannonville:
Qualified: DNS
R1 (60min): DNF* Turbo Failure (too much 2step in the past killed HKS!) poor guy

Race 5 @ Mosport:
Qualified: 3rd
R1: 2nd
R2: 2nd

Race 6 @ Mosport:
Qualified: 2nd
R1: Last** (intercooler pipe)
R2: Last** (intercooler pipe again - obviously no welder to make a bigger bead)

Race 7 @ Mosport:
Qualified: 1st OVERALL
R1 (3hr): 2nd DQ’d (passed lapped car under yellow)

Race 8 @ Mosport:
Qualified: 1st OVERALL
R1: 1st
R2: 1st OVERALL FLO

If you think thats bad, apperently I had a very reliable car for most converted street cars or even race cars out on their first year. By the end of the season the car was sorted and very reliable.

Some info on the classing:

GT: Basically unlimited (thats me)
T1: Speed World Challenge Touring spec give or take
T2: Showroom Stock (although there are some fast cars here!)

The T1 guys include the Auto Analyzer SWC Lexus IS300 that I fought with all year, and the K24 Honda sponsored new civic (VERY nice race car). We all had about equal power (the S14 was arguably the slowest GT car on the back straight), but I made up for it with tire and aerodynamics. (T1 guys can run a max of a 235).

If we weren’t DQ’d from the 3hr and I had finished just one more race without a DNF (maybe 2) I would have won the championship!

[DTS]

ive seen the way you drive…

[cvm07]

Good job on the first season. I was there to see you run the 3 hour Race. I was there with a buddy (who is buddies with the guys with the old Sirroco, it was there shake down run that day). Good run for you!!!

Got to be happy with what you did your fist season. Anytime you start racing with little to no help, and you can start the next season without having to rebuild your car because you didn’t destroyed it, sounds good to me!!!

Alignment on a race car can make a bigger difference then most would think, Oh and keeping up with a fully race spec IS300 worth maybe $200,000. Now that’s amazing. That Civic is hella fast too.

Good luck next year,

CVM07

[Happy240sx]

Sasha = your linky is dead to that video

[Theo23]

I have been to Mosport a bunch of times, I would love to drive that track!
That corner 2 is nuts, probably a good place to benifit from unexperienced divers and overtake. Corner 5 is my favorite place to watch, you can see them exiting 3, through to 5 and all the way up the back straight. Of coarse when you stand outside of #3, you can see the carnage in corner 2 all the way to 5a

You are totally right when you talk about driving at a level that is representative of your skills. That is easier done when gripping I think. My reason for this is that, when gripping, there is a definite line between grip and sliding (slight loss of traction when trail braking etc. excluded). When you are drifting, there is not such a defined line between sliding and sliding too much. You can get good at sliding at slower speeds, but to step it up to the next level, sometimes you have to use different techniques that will not work at slower speeds. There is definitely a difference in the learning curves between grip and drift.

I am not saying one is easier than the other, they are both very different from eachother, yet similar in some ways too.

With drift, you don’t usually have to hit the corner at 100% every single time. ie; highest entry speed with the greatest angle while still clipping the apex and then setting it all up for the next corner. You can usually hit it at maybe 80-90% and still be looking really good.
When grip racing, on the other hand, you have to hit that corner at 95-100% every time. That is tough, but you have to keep the consistency as you said.

So, with that said, when are we going to have a SON240 lapping day at Mosport!!!

[cvm07]

I would love to do a lapping day at Mosport!!! BUT, do to insurance costs at that track, It would cost way to much. If it could be done at all!!!

[Theo23]

Yeah I hear ya… sooo the only other option is…

Get me a Bike!

[a_ahmed]

Awesome thread, i just read it all. I wish there was more threads like these on son. :thumbup:

I love your journal/write up.

Your video link is however broken.

[Sasha_SG]

Thanks for the kind words guys, link is fixed.

I named it “mosport.wmv” but then windows movie player threw in another .wmv for no reason so it was actually “mosport.wmv.wmv” silly.

Theo I totally agree, differnt skill sets. Some guys race with 0 car control. They’ve just never needed to learn it.

[a_ahmed]

you should do an in car video Cool clip though.

[ADAM]

good job this season sasha…

good work…

[Sasha_SG]

Thanks Adam, means a lot dude

heres another clip

http://www.sequence-garage.com/mosport2.wmv