SCCA ST165 finally begins

CMS-GT4":1ryu1ebh said:
I been watching the build on Instagram. I can't wait to see how this thing does on the track.
I assume you watched the two RunOffs videos I posted the other day?... But yes, I hope it does much better this coming season! Confidence in my brakes and having them last a whole race should improve my pace in itself let alone some other improvements... HP is still a big concern though!

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MWP

New member
eric thompson":1nnd8fuf said:
They are on, some modifications needed, and will be tested as soon as possible, weathering permitting... Overall geometry seems to have improved... But the real proof will be on track.

I'll lap up any information you are willing to give away :)
The main questions i have concern the steering arm length (will effect bumpsteer & ackerman), lower ball join to hub offset (effects drive shaft length), and strut ear width/bolt-spacing (will effect if gt4 strut will bolt up).

Whats the instagram address?
 
All the attachments will have to be custom... We made lower ball joints offset to increase caster since they had to be made anyways... Looking at the Prius and ST185 ball joint bolt patterns though they look very similar... So you might get away with bolting up the Prius BJ to the 185 LCA.

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MWP

New member
So the lower lower ball joint you have in those photos are the original Prius items?
If i were going to do this (i'll strongly consider it), then i would probably make up a custom LCA too. I also want to dial in a little more caster yet, my current 3.75° isnt quite enough.

Having to make a custom strut leg isnt ideal since i did it not that long ago to fit my newish Koni Racing inserts, but if needs be.

Hmm, i recently decided i was going to leave my 185 in its current state for a few months. This, and a quick look through your build photos has me all inspired again :p
 
received_10211018624851068.jpeg Custom BJ's moves lower pivot forward about 1 inch. Prius BJ wouldn't bolt to my 165 LCA but from memory the 3 bolt pattern looked very similar to a 185... With the knuckle being aluminum all the attachment points are thicker so the tierod end shaft and BJ shaft are a bit longer than our cars with steel uprights...
received_10210933416320908.jpeg
received_10210650565929825.jpeg

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klue

New member
Are you worried about the integrity of the spindle under racing conditions? IE how the heat will affect the strength of the spindle
 
By spindle I assume you mean the aluminum Prius upright/knuckle?? Honestly I am not overthinking that aspect... A couple hundred degrees shouldn't compromise the integrity of aluminum

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CMS-GT4

Active member
eric thompson":2j2og32y said:
CMS-GT4":2j2og32y said:
I been watching the build on Instagram. I can't wait to see how this thing does on the track.
I assume you watched the two RunOffs videos I posted the other day?... But yes, I hope it does much better this coming season! Confidence in my brakes and having them last a whole race should improve my pace in itself let alone some other improvements... HP is still a big concern though!

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I did not. I had been following Seamus. I need to find your profile on there.
 
We had also fitted some Highlander rear knuckles as they were also 26 spline axles but decided to modify the OEM 165 rear knuckles to accept the same Prius hubs.. here's what Seamus built and designed as well... received_10210755681597651.jpegreceived_10211088650801673.jpegreceived_10211088653481740.jpeg

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CMS-GT4

Active member
eric thompson":3fxw9b0g said:
No IG profile for me... Too much T n A rotting my brain :)

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Self control. ;) Only porn I look at on there is car porn. I use it for business though, and people see what you like.

eric thompson":3fxw9b0g said:
I have plenty of build pics and updated components to add to this thread but time is limited. I do have two videos though...

https://www.scca.com/videos/2029784 This is the SCCA live broadcast. If you cant bare to watch the whole thing I get some good coverage at about the 17 & 30 minute marks.

https://www.youtube.com/watch?v=VwTQqKxBzOY This is the in-car video from the same RunOffs championship race.

And unfortunately the front hubs/bearings failed again that weekend, twice! The second time being during the race. I started losing the brake pedal gradually and had to finish the last two laps with the handbrake... but finishing is what counts!

That was a good video. Nice coverage. I don't know how I missed it. Car seems pretty strong considering you have a few things to work out.
 

MWP

New member
eric thompson":2lk5l7ev said:
We had also fitted some Highlander rear knuckles as they were also 26 spline axles but decided to modify the OEM 165 rear knuckles to accept the same Prius hubs.. here's what Seamus built and designed as well..

Well thats different.
If possible, I think i would be more in favour of using the Prius front upright on the rear, make a new LCA and an extra bar to lock out the steering.

Thanks for the continuing info & photos btw. Its GT4 info gold :)
 
55943db162ab9e4734deda7361572185.jpg
 
CMS-GT4":1beaj6su said:
eric thompson":1beaj6su said:
No IG profile for me... Too much T n A rotting my brain :)

Sent from my XT1650 using Tapatalk

Self control. ;) Only porn I look at on there is car porn. I use it for business though, and people see what you like.

eric thompson":1beaj6su said:
I have plenty of build pics and updated components to add to this thread but time is limited. I do have two videos though...

https://www.scca.com/videos/2029784 This is the SCCA live broadcast. If you cant bare to watch the whole thing I get some good coverage at about the 17 & 30 minute marks.

https://www.youtube.com/watch?v=VwTQqKxBzOY This is the in-car video from the same RunOffs championship race.

And unfortunately the front hubs/bearings failed again that weekend, twice! The second time being during the race. I started losing the brake pedal gradually and had to finish the last two laps with the handbrake... but finishing is what counts!

That was a good video. Nice coverage. I don't know how I missed it. Car seems pretty strong considering you have a few things to work out.
Confidence when threshold braking should account for improved laptimes... But if you notice my fastest laptimes was still 2.5 seconds off the fastest guys... Theres a lot more behind the scenes within the class regarding parity and how I personally view certain rules. Everyone thinks the Lotus should be removed mainly because it's a factory built race car, it's flat bottom, real down force generating vehicle that also makes good power, is light, and handles extremely well. Personally I like it! It's very limited beyond how it came from the factory and it's a hanging carrot as far as I'm concerned...
But I think the SCCA needs to wake up and stop limiting areas that would help other vehicles, especially forced induction, catch up...
Plus their balance system is antiquated. Power to weight makes sense but there's more to the equation.
A given vehicle must use the Turbocharger originally equipped on the installed engine or 1 of 3 other approved alternates, Garret GT2554, K04, or VF30... None of which will give any performance advantage over a CT27.
Then there the Turbo inlet restrictors based on weight. My car would get a 37mm but all RWD & AWD vehicles take a -2mm penalty. So I get 35mm... Which raises one of my concerns...
Where in any of these Forced induction restrictions does engine displacement get factored in?? Yes, in the end airflow will be the limiting factor, but common sense tells me(for example) that comparing a 2.0L alltrac with a 35mm and a 2.5L STI at the same weight and 35mm, the engine with 25% more displacement will have a broader more usable powerband and make more power comparatively. And if the TIR is the best single limitation device, then why restrict what Turbocharger is allowed to be installed?? No matter how big it can only pull "X" amount of air through the TIR...
Next is the Hondas, a built H22 or K24 will be, and obviously is, a powerhouse and they weigh between 2500-2700 lbs. A good 300-600lbs less than my alltrac. Making way more WHP.
Insult to injury, the Lotus' also only weigh 2200-2400 lbs making more WHP too...
Trust me when I say I am fighting the balance scales and also trying to squeeze everything I can from our CT setup. Contemplating running an 8cm 64 AR single scroll Turbine housing on a tubular exh manifold and ext WG just to reduce the restrictions on the hotside and give better boost control... I'm sure the difference will be negligible though.
:(
That's my rant for now

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CMS-GT4

Active member
I noticed the announcer say you can use any engine from a manufacture as long as its the same displacement. Can you take a 3rd or 4th gen gte, which has a better VE and bigger turbo and maybe do better with it than the engine you are running? All these scca rules are the same reason the 185 isn't very competitive in most stock classes too unless you are building a full out race car.

EDIT: How much did you car tip the scales? Is there more places to shed some weight, or is it all about expensive composites at this point.
 
I'll pm you the rules.
If memory serves correctly... me in full gear, 15 gallons of fuel and a full cool suit cooler(24 quarts) it was approx 3150 over the scales.
I'm 175 in gear, 6.183 per lbs per gallon of fuel(92.75), and 8lbs per gallon of water(48lbs) rounding up that's 316 lbs... So she's 2834 +/-

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CMS-GT4":1qgvrj5x said:
I noticed the announcer say you can use any engine from a manufacture as long as its the same displacement. Can you take a 3rd or 4th gen gte, which has a better VE and bigger turbo and maybe do better with it than the engine you are running? All these scca rules are the same reason the 185 isn't very competitive in most stock classes too unless you are building a full out race car.

EDIT: How much did you car tip the scales? Is there more places to shed some weight, or is it all about expensive composites at this point.


May switch to a 4th gen 3SGTE later on but since my 185CS motor has minimal hours on it and was quite an investment with the COP, Billet CT27, and custom everything else, I'm going to see how much farther it can go... since the turbo is allowed to be modified for boost/wastegate control, i may switch to a single entry Supra turbine housing and custom tubular manifold to free up the restrictions on the hot side... trying to squeaze anything I can out of it.
Also may opt for better gear ratios for a longer 1st gear and stack the rest closer together when I install the Quaife diff...

No composite body panels allowed except for Hood (which mine is FG) and trunk, which is really light with no glass in it.

Best gear ratios I can find...
 

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