Eric's BRZ - A motorsports engineers perspective

[jdmblood]

that evo 8...

[eric6]

Originally Posted by Roxy86

I thought C&R was based out of IN?

We are. I am out here lone wolfing it as a West Coast sales rep/sales engineer/design engineer.

Originally Posted by jdmblood

that evo 8...

I miss her too, that car was always fun to drive. Some more of my favorite shots with her.

[eric6]

Put some time in on the computer getting the mocked up splitter ties in. Should turn out pretty nice looking once we produce them.



Windows tinted!!!! (not a good picture)



Finished the exhaust. The whole system weighs 8.4 pounds. I think I'll add some nice tips to it as well.

[Shedd22]

I'm a mechanical engineer also (graduated last year). I've been working on designing/tweaking some parts too. Haven't gotten around to doing much FEA but did some vibration testing. Haven't made a build journal yet since I bought my car two months ago. I'm interested to see what you do..maybe it'll help me in my designs. Good luck!!

[eric6]

Originally Posted by Shedd22

I'm a mechanical engineer also (graduated last year). I've been working on designing/tweaking some parts too. Haven't gotten around to doing much FEA but did some vibration testing. Haven't made a build journal yet since I bought my car two months ago. I'm interested to see what you do..maybe it'll help me in my designs. Good luck!!

Sounds good, have fun with it. That's the reason I do this, I enjoy it.

I took some daytime photos of the exhaust and drove around with it for about 50 miles. It's got a nasty resonance at 2-2.5k RPM, I will be adding a helmholtz tube to stop this. Other than that it sounds pretty good and weighs 30 pounds less than stock!

Likely will be adding some tips to this, thoughts?

[Shedd22]

Originally Posted by eric6

Sounds good, have fun with it. That's the reason I do this, I enjoy it.

I took some daytime photos of the exhaust and drove around with it for about 50 miles. It's got a nasty resonance at 2-2.5k RPM, I will be adding a helmholtz tube to stop this. Other than that it sounds pretty good and weighs 30 pounds less than stock!

Likely will be adding some tips to this, thoughts?

Yes to tips.

[inertia]

Excellent welding skills man!

[frsvr4]

Originally Posted by Shedd22

Haven't gotten around to doing much FEA but did some vibration testing.

Any details on the vibration testing? Frequency, acceleration levels/profiles, duration?

Eric, it looks like you use SolidWorks. Have you used it for vibration analysis beyond simply determining natural frequencies?

I <3 this thread

[gramicci101]

On your MR2, what's the black gear-looking thingy (technical term) between your intercooler and the RacerX manifold? Are there any drawbacks to having an aluminum exhaust? Also, if you need another bike, I'm selling mine.

[eric6]

Originally Posted by Shedd22

Yes to tips.

Yep, it doesn't look finished. At first I liked the Lamborghini kinda look but it needs something there.

Originally Posted by inertia

Excellent welding skills man!

They're far from excellent but thank you .

Originally Posted by AdamVR4

Any details on the vibration testing? Frequency, acceleration levels/profiles, duration?

Eric, it looks like you use SolidWorks. Have you used it for vibration analysis beyond simply determining natural frequencies?

I <3 this thread

I use Solidworks for home stuff, I use ProE and Creo for work. I have not used vibration analysis actually. I typically FEA parts while my friend does most of the CFD stuff. Personally, I like designing nice looking parts, I'm a design guy . My friend/partner is the true genius with CFD and other analysis.

Originally Posted by gramicci101

On your MR2, what's the black gear-looking thingy (technical term) between your intercooler and the RacerX manifold? Are there any drawbacks to having an aluminum exhaust? Also, if you need another bike, I'm selling mine.

That is the throttle cable wheel of a humongous 90mm RMR throttle body. Yes, aluminum does melt at ~1100-1200 degrees and is considerably more susceptible to cracking, corrosion, and possibly melting. If done right, I don't see an issue arising for many years to come. I would be surprised to see an issue with anything under 60k miles, but that is an estimate. Time will tell .

Please let me know what you have and how much... you aren't far from me.

[gramicci101]

Originally Posted by eric6

That is the throttle cable wheel of a humongous 90mm RMR throttle body. Yes, aluminum does melt at ~1100-1200 degrees and is considerably more susceptible to cracking, corrosion, and possibly melting. If done right, I don't see an issue arising for many years to come. I would be surprised to see an issue with anything under 60k miles, but that is an estimate. Time will tell .

Please let me know what you have and how much... you aren't far from me.

Ah, for some reason a throttle cable didn't occur to me.

Ok, so it would need to be steel until the temperature dropped off enough, then switch to aluminum? Are you going to have it anodized to prevent corrosion? Since you have the ability to remake it if it breaks, it should do you very well.

bike

[eric6]

Originally Posted by gramicci101

Ah, for some reason a throttle cable didn't occur to me.

Ok, so it would need to be steel until the temperature dropped off enough, then switch to aluminum? Are you going to have it anodized to prevent corrosion? Since you have the ability to remake it if it breaks, it should do you very well.

bike

Here's a few more photos. I really need to rebuild the whole intake manifold side of things to make it cleaner but no time right now. Been waiting for my engine for 1.5 years .





Correct. On the MR2 I went right after about 24" of downpipe to aluminum. No issues, but the turbo sucks a lot of energy and thus heat out of the engine. With our cars, I think everything from overpipe back could be aluminum. I want to measure temps before I go that far forward. I don't anticipate many issues with this exhaust.

Thanks for bike link.

[gramicci101]

Will you be making a diffuser to cover the hole left by the OEM muffler and prevent any kind of parachuting effect? I read somewhere that the OEM muffler was an active part of the underbody aero on our cars.

Also, that throttle body is enormous! I can see how the original one would be a restriction.

[eric6]

Originally Posted by Shedd22

I'm a mechanical engineer also (graduated last year). I've been working on designing/tweaking some parts too. Haven't gotten around to doing much FEA but did some vibration testing. Haven't made a build journal yet since I bought my car two months ago. I'm interested to see what you do..maybe it'll help me in my designs. Good luck!!

Forgot to say, if I can help make any of your parts come to life, let me know. I recently graduated as well (2013) and we gotta watch out for each other .

Originally Posted by gramicci101

Will you be making a diffuser to cover the hole left by the OEM muffler and prevent any kind of parachuting effect? I read somewhere that the OEM muffler was an active part of the underbody aero on our cars.

Also, that throttle body is enormous! I can see how the original one would be a restriction.

I haven't thought about a diffuser yet but I probably need one. With how large that muffler was, I have no doubt that it helped keep air going out the rear instead of getting lost in the bumper. It's on the very long list, I don't race the car (yet) so I'm not worried about it.

Yes, that throttle body is huge. The one it is sitting next to is 75mm (3" dia.). I "upgraded" because I got tired of rebuilding the 75mm. I don't think that throttle body was built to handle 28psi . Seals on the throttle shaft kept blowing out.