SCCA T4 Build thread

[NoHaveMSG]

More then likely they undershot the design requirement a bit. It is a parts bin TOB. Changing grease is not a big deal, I just had to make some changes to a small 1641-2rs that we use and going from a base lithium soap grease to a higher end synthetic had negligible cost difference, and I don’t buy in big manufacture quantities, I’m talking 5-7k a year.

Some of the grease cooking could also be from diff heat breaking down the grease on top of exhaust temps.


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[rice_classic]

So after the runoffs I wondered where my power had went and part of addressing that was to start with the squirt...

This engine has lots of miles so it stands to reason that the injectors may need to be serviced. So I pulled them out and off to the Injector Doctor I went! The Port injectors weren't that bad but the DI injectors were uneven in rates and he said the patterns were very off and said that if this wasn't a D4-S car and was DI Only, that I might have even had a rough idle from what he saw in the spray pattern.

Good thing too!


The downside is that on the GDI Injectors, I didn't realize there 3 seals on rail side of the injector, a concave seal, a rubber seal and "backup" seal. I broke 1 back up seal, and lost another one. So off to the dealership I sent to get new ones.



Now Dr. Injector said the DI Injectors go back into cylinder head "Dry", but the seals on the rail side can be lubed with some oil, but I used a little dialetric grease. So before you go in dry, make sure the holes are clean!


Thank you Harbor Freight!


I was really concerned about installing the direct injectors because they do NOT go back in the holes all that easily. They all went equally difficult but they all took effort. Here's the thing, I found Bosch documentation that says "go in dry", the injector guy said to insert dry and the FRS workshop manual does not say either way but the toyota tacoma manual (same injectors) does mention lube. So I'm stumped. I think the next time I do this, since these use teflon seals, I will probably use a little teflon based dry lube and call it even.

Now the manual says you should get new hard lines that go from the HPFP to the rails and between the rails but I was careful removing them and careful reinstalling them. These same type of lines are used in many other applications where replacement during servicing isn't required so that's the risk I took. I did make sure to lube the ball and seat before connecting their interfaces.


I started her up and she sounds great. Let here come up to temp and all 8 injectors are clicking away as they should and no fuel leaks. I hope this means I did everything right and everything works in race conditions. I hope to get a track day prior to the next event but I'm hopeful that this recaptured a few of those lost ponies.

[Racecomp Engineering]

Hole lot of innuendo in that post, but that's good info. How many miles and approx track/race time on your car?

- Andrew

[solidONE]

And I have never seen Q-Tips shaped like 2 lemons attached to the ends of a stick before this post. Thankful.

[rice_classic]

Originally Posted by Racecomp Engineering

Hole lot of innuendo in that post, but that's good info. How many miles and approx track/race time on your car?

As for mileage - it has 87k on it but about 30, maybe 40 "race hours" since it's been converted. Spark plugs and a leakdown or compression check are in order as well.

Originally Posted by solidONE

And I have never seen Q-Tips shaped like 2 lemons attached to the ends of a stick before this post. Thankful.

I have a 1 year old - those are Q-Tips (cotton swabs) meant for babies as they help limit depth of insertion.

[dsc_pat]

This topic is amazing, thanks for sharing the journey. I red it all.

Been around RRAX on HT since early 2000s and I knew your nickname sounded familiar, so this feelsgood too. Amazing to hear about this story after HC.

What you did with the Bilstein regarding the spring seat is amazing as well.

Cheers and keep us posted,

[NoHaveMSG]

How many sets of tires are you going through and how many events per season?

[rice_classic]

Originally Posted by NoHaveMSG

How many sets of tires are you going through and how many events per season?

2019: I believe I did 12 events between SCCA and ICSCC. I went through 5 sets, 2 of which were purchased and 3 of which were donated by a competitor who was discarding his lightly used takeoffs.

2020: 7 events and 3 sets. I used what still had life from the previous season but then purchases 3 overall saving a fresh set of stickers for the runoffs.

The A7 stickers I ran at the runoffs still have plenty of life and I bought 2 sets so I have (3) going into 2021. Hoping to only need to buy 1 or 2 depending on how much racing I can do this year. If I can find well funded guys that have 1-2 session take offs, I'll try to buy those at a discount vs buying new.

This car is pretty good on tires. The R7s get retired with tread still left on them (cycle out) but the A7s are fast until they cord. The only trade off is temperature. Can't run the A7s on hot days. Because we have milder temperatures in the PacNW for more months out of the year vs the rest of the country - the A7 is a good tire for us for much of the year.

[WheelrDealer]

Glad I found this thread. I am working on a FR-S/86 T4 myself. I am new to road racing and will spend a year or so at my local track (Gingerman Raceway, South Haven, MI) and attending driving school to develop some novice skills before I attempt to attend any events. Your videos demonstrate to me how much I have to learn.
I learned that my beautiful Tomei header is for now wall art. I missed the rule on stock header. Also I bought RaceEng rear 2" mounts and they may not be legal either.
My car started as a hydro-locked flood salvage car from Copart. No water in the interior just sucked water into the intake and bent a rod. I have a second car that is hit all over but perfect 29,000 engine, 6 speed, computer, pedals and assorted spares. Currently I am in the que at the cage fabricator with a March 17th appointment. The good ones are always busy. My plan is to build as much of the car as I can before it goes to the Fab shop.
Your post about tires, struts and 2 part interior paint have been most helpful.
Thanks,

[rice_classic]

Originally Posted by WheelrDealer

Glad I found this thread. I am working on a FR-S/86 T4 myself. I am new to road racing and will spend a year or so at my local track (Gingerman Raceway, South Haven, MI) and attending driving school to develop some novice skills before I attempt to attend any events. Your videos demonstrate to me how much I have to learn.
I learned that my beautiful Tomei header is for now wall art. I missed the rule on stock header. Also I bought RaceEng rear 2" mounts and they may not be legal either.

It's time to start your build thread!

You should be able to sell the Tomei header though. The Raceseng rear 2" top hats are legal as per the GCR spec line for the car. They work alright with the MCS shocks since they are shorter bodies - although I'd do the 1" top hats if I had to do it over again. However if you use bilsteins you'll likely want to run the OEM top hats.

I ordered my MCS shocks from Dynasty out of Florida - if you go this route, give them a call and let them know what you're building - also I recommend getting their custom Spring Perches as well as you'll need those to adapt the Eibach springs.

Your fancy slotted rotors aren't legal either, so you'll want to try an sell those before you put any wear on them. The best rotors I've found are the "High Carbon" Duralast brand from Autozone and the "Ultra 8" brand from Napa (P/N ATM HC31407X). These have the best resistance to cracking I've found and I get several races out of them.

[NoHaveMSG]

Were centric blanks not holding up? I just ordered a full set so I can start pulling the BBK off my car.

[rice_classic]

Originally Posted by NoHaveMSG

Were centric blanks not holding up? I just ordered a full set so I can start pulling the BBK off my car.

They'll be fine and are solid - great quality control, consistency and the cooling vein design is ideal. I wish Centric made the 125 series for our car though as the high carbon content allows them to last a bit a longer under the conditions we put them through.

The other two I mentioned seem to have the same durability as a 125 Centric which is why I landed on them. If Centric starts making the 125 for our cars, they will go into the rotation.

[WheelrDealer]

Originally Posted by rice_classic

It's time to start your build thread!

You should be able to sell the Tomei header though. The Raceseng rear 2" top hats are legal as per the GCR spec line for the car. They work alright with the MCS shocks since they are shorter bodies - although I'd do the 1" top hats if I had to do it over again. However if you use bilsteins you'll likely want to run the OEM top hats.

I ordered my MCS shocks from Dynasty out of Florida - if you go this route, give them a call and let them know what you're building - also I recommend getting their custom Spring Perches as well as you'll need those to adapt the Eibach springs.

Your fancy slotted rotors aren't legal either, so you'll want to try an sell those before you put any wear on them. The best rotors I've found are the "High Carbon" Duralast brand from Autozone and the "Ultra 8" brand from Napa (P/N ATM HC31407X). These have the best resistance to cracking I've found and I get several races out of them.

Thanks, good info.

[rice_classic]

So I've been obsessing. Mainly because it's the off-season, I'm bored, have cabin fever and am trying my best to keep sane.

Before the obsession let me start with an update:

New Part:
I have now installed what is the equivalent of my 4th edition of my exhaust and now I have 3" from the header back. The JDL front/overpipe are beautifully made and fit great. But god almighty was it a trick to install and a damn tight fit.

Restrictor plate - I can share a racing secret since it's now been banned. In T4 our car requires a 55mm Flat Plate Restrictor. What I did was stretch the meaning of "plate" as I found out there was such a thing as 1" aluminum plate. So instead of my restrictor plate being 1/8th" thick, it was 1" thick so the 55mm hole allowed the air to 'smooth out' as it passed through the restrictor. I tested the difference between the 'skinny' and the 'fat' restrictor plates and the difference was 2 WHP. That's a big deal. However it turns out that this type of thing was happening in other Class(es) and the SCCA changed restrictor thickness to no thicker than 1/4". So now my 1" restrictor plate is a fancy paper weight.

New to this year: I have a 'skinny' restrictor, a different exhaust setup, new HKS cold spark plugs and clean injectors. At the Runoffs I was down about 5-ish WHP on Totemo so I'm going back to the Dyno tomorrow in hopes I can find those missing ponies despites the skinny restrictor.

Obsessing
Ride height, roll center, Australia GR86 race cars and air flow.

So I was watching a lot of the TR86 Race Series (now called GR86) which is a support race series for the Aussie V8 super cars. I noticed a couple things about the cars: 1) they run at almost stock ride height, maybe 0.5-1" lower and 2) they only run the front (metal) undertray. I can't find the rules anywhere so I cannot confirm if they run at that height because it's a mandated min ride height or if they do so because it's optimal - generally in spec series, "optimal" get's identified and adopted en masse very quickly.

I figure the lack of the 2nd undertray is probably due to service intervals or air flow. But the ride height is really what stuck with me and I started looking at the suspension geometry.

After looking at roll center information and taking the MASSIVE risk that assuming what I read on the internet is true - I started measuring my ride height where I measure from the top the pinch weld (as is the point of measurement by the SCCA). There was I was about 5" front and 5.25" rear height. After measuring based on how Toyota does it: Center of wheel to top of arch I was at 12" and change, which was about 2.5" or so lower than stock. I didn't realize I was that much lower than OEM.

Stock ride height:
Front wheel arch to wheel center: 375mm or 14.76”
Rear wheel arch to wheel center: 372mm or 14.65”

Supposedly the roll center on these cars goes way below the ground plane after 1" of lowering, because we cannot run roll center correction kits (rules) or change our springs or bars to account for the additional moment of roll, I am possibly operating enough outside of optimal suspension geometry that it may actually have detracted form performance.

Second to this there is evidence on the bottom of my car that maybe being that low ain't the best for it (dents in exhaust etc). I have now raised the car about 1" so it will be interesting to see how she drives with that change. The ancillary benefits I'm looking at are improved cooling, less stress/heat on the CV and better clearance for riding curbs or setting tires off. While raising car does raise the CoG, it also decreases the distance between the roll center and the CoG reducing the total roll so it's possible I can retain the same balance and corning grip while also enjoying the safe ride height. I'm really hoping that's the case because every time I drive over a berm/curb or leave the racing surface my first thought is "Oh for sure, that broke something."

We are all headed down to Thunderhill in a couple weeks for the SCCA Majors event so I'm hoping to come back with some solid real world feedback on my "obsession".