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what is your plan for balancing the rear with the 3" splitter? I thought you were already running 0* AOA? I could be wrong about that. Is there a point hit for a 4" splitter or is it just entirely illegal?
what is your plan for balancing the rear with the 3" splitter? I thought you were already running 0* AOA? I could be wrong about that. Is there a point hit for a 4" splitter or is it just entirely illegal?
I'm really curious to see how GLTC goes over the next couple of seasons. It'd be cool if it expands to multiple tracks and maybe becomes THE catch-all w2w series.
Engine is in.
Engine is through its first oil change, needs a second swap for the Amsoil dominator race oil, then a thorough tune with our external/optical rpm pickup.
Still debating the pro/con of a splitter. It costs me .5 penalty in P:W, roughly 75lbs in current 139whp config.
A minor improvement in radiator ducting has been made, and a cool comparison photo was taken of a Supermiata S2/ST5/ST6 airdam undertray laid under a Supermiata S1/ST5/ST4 4” splitter. The birch plywood tray is from Renderos Racing. I bought one of his kits Incase I decide to delete my splitter for the P:W bump, or for Gridlife GLTC use.
New engine is in. Its been to the dyno a couple times. It is shy of our power goals. We're all kind of stumped. A few other engines with very similar builds have landed in the 160-165 range, this one should have too. But our best run so far has been 151.44, SAE Dynojet, smoothing 5 for NASA ST rules.
I've double checked cam timing, swapped to amsoil dominator race oil, fresh clean air filter, new muffler(Racing Beat's new Power Pulse Race Muffler, look for it on Supermiata.com) and just generally gone through the car looking for any and every little problem. It makes 151whp on corn.
So, without the 151-158 Average, I can't ballast up to 2400lbs. That means I can't run 9" wheels or 225 R7s. So, I'll stick with my light weight 2250lb build, with splitter and 205s on 8" wheels.
The car is capable of being sub 2215lbs with me in, so I need to add about 40lbs of ballast to keep from going under 2250 if I run it out of gas.
With no ballast added, and no fuel, my 1999 miata weighed 1999lbs on the hub stands, kinda cool.
NASA SoCal. 3 in ST5 Saturday, 1 in ST5 Sunday. So I TT'd only.
11 in TT5 Saturday turned into 8 Sunday.
Basically, right off the trailer onto the track. Session 1 Sat morning is warmup/practice, times don’t count. I ran it on 225 RC1.
Session 2 was timed, and good conditions. I swapped to some fresh R7s and ran a new PR. 1:58.75.
Peep that new Racing Beat Race muffler:
Team TAPG (Toyota Arizona Proving Ground) threw in their hotshoe, and a set of stickers and nudged me out in session 3. So I had to go back out in session 4.
I went through my data and found several places for improvement for session 4. One of the best drives in recent memory, and I was able to drop some time, but I was not able to outpace the terrible conditions. 80* ambient, windy, 105* surface. If I had been a bit more familiar with the car, or had a test day...
We put 3 seconds on the field. J Allan in P3 won a PTC championship alongside me(in PTE) in 2016 and is no slouch.
Day Two:
Session one, best conditions, now counts for competition. I went ham. Again, THIS session was some of my best driving in memory. Data review from the day before, tire data from the day before, fantastic conditions, no breeze, cool air, no clouds. So good.
Buttonwillow was good. 1st/2nd, 3 new Hoosiers and a track record. I am still reliving the memories of the 1:58 laps in my own car.
Shortly afterwards, we took the car back to the dyno for a checkup and things didn't go well. The car sputtered weird and died pulling in onto the dyno and wouldn't re-fire. I pulled the engine out and had Keegan tear it down as we could not identify anything wrong externally(timing/ignition/etc)
Turns out I had some debris in my oil cooler from the previous engine that killed the bottom end, and as our theory goes, probably accounts for the missing 15whp. Mike was able to save the rods and cams, but it needed new bearings and a fresh donor block.
That engine is on its way back to the fellas at 949/SPM to get broken in and tuned before heading over to me for the run-up to NASA Championships.
Since then, a lot of life things happened. My wife received an offer for a promotion that brought us back to Columbus, OH. Ed May came on board to fill my seat and he got a couple whirlwind weeks of training in March before I left to move east in late April.
We did some fun Land Cruisering even with the trailer behind us. Lake Havasu, AZ BLM camping, Nat'l Forest rd camping at the south rim of Grand Canyon, then a bunch of boring highway across Texas and up to Ohio.
Lots of "life" happening lately, not much racing or anything with my own cars. Some cool stuff I can share soon, but also a lot of ****.
Earlier this month my engine arrived from the builder. I did quite a number on it with the oil cooler debris so the repair/rebuild actually cost me a new core engine. The timing of the k24z3 swap hurts, bad. I have semi-joked about this, but I really hope this is the last BP engine I ever invest in.
Oh well, its in.
Keegan told me not to reuse the orange valvecover without new baffle plate covers. The dude obliges.
I ponied up for a multiple-hour professional tune and it runs so smooth now. It doesn't make any more peak power, but drivability, idle and part throttle transitions are butter now.
I'll likely get compliance tested on Saturday, so I am hoping that burning off whats left of this 3-4 month old e85 and another hour or two of run time shows up for another 3-4%, but I doubt it.
The scaling on the printout makes it look peaky, its not. It makes 152.33 peak and 148.75(149) NASA Average. My previous two engines had 5 and 9whp drops from peak to average. This one is really healthy and sounds/feels as good as the fully forged "zero point" engine I ran in 2016 and that went on in Bullet to TSE goodness.
Being realistic about what this engine is, I am not sure if 160+ was a valid goal. I look around for real life examples of similar builds and they all have Tomei cams, coatings, more compression, or ITBs to make more.
It is "just" a refreshed .5mm oversized BP5A with a little hand porting and +1mm valves. A mod list sometimes makes it sound more wild than it is.
Mazdacomp cast 84mm pistons 10.5:1 (OEM JDM service part)
OEM MSM/JDM BP5A intake cam
OEM EUDM intake manifold with light throat porting to match the S2 TB.
+1 Supertech valves
e85
The rods, studs, throttlebody and crank damper are reliability stuff, not power.
Anyways, it makes enough power to justify running at 2400lbs so I can fit up to 257mm tires in NASA ST/TT. Woot.
That means 225 R7 on 9 or 9.5" wheels. I've been running these not-very-attractive 9.5" Konig Freeforms since they, for some reason, found justification for the half size and they feel awesome on the TT6 car.
I didn't think it would be such a big change, but the way the car drives at 2200 vs 2400 is wildly different. I much prefer the lighter car as a Driver.
Also, the stupid frickin OEM subframe Kswap won't leave me alone. This BP4W, back on pump 93, would be an 'ideal' 6 engine, and we have an ST6 NB1 that could use it...
That would free Button up to receive a K24z3 this winter...
If I end up keeping the BP, then i'll probably knock the peak down a bit and pull the weight back out of it. The 2200lb car was way more fun last year.
01-13-2019, 06:30 PM
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