Trav’s Race Build: from B6 to Big Bore BP-Z3

Scoota · Postby **Scoota** » Fri Aug 30, 2019 4:08 pm

Hi Folks.

I’m shopping for a filter to go with my 75mm ITB trumpets. I’ve been warned away from the four individual socks, so this looks like the obvious choice...

https://www.uniflow.com.au/contents/en-us/p5842.html

Any objections or alternative suggestions?

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ManiacLachy · Postby **ManiacLachy** » Fri Aug 30, 2019 4:32 pm

I believe the big issue will be the brake master cylinder interfering with the filter around cyl 4, maybe cly 3. So depth is important. I couldn't tell you what size though sorry.

ManiacLachy · Postby **ManiacLachy** » Fri Aug 30, 2019 4:39 pm

Also, I feel like you're ignoring a lot of experienced advise suggesting you re-consider the ITBs. They're a lot of work for very little gain, most who do it say they wouldn't do it again. I'd go with the stock manifold, at least initially, then if you feel it's needed, add ITBs for that last little bit.

StanTheMan · Postby **StanTheMan** » Fri Aug 30, 2019 5:16 pm

ManiacLachy wrote:A then if you feel you need to go over the edge, for that last little bit. there is always 11

eleven, that's noot the Scotts in a voice activated lift.....which goes nowhere

ITB's go to eleven

Scoota · Postby **Scoota** » Fri Aug 30, 2019 6:42 pm

Hi Folks.

Please don’t get the impression that I’m ignoring your advice. I’m considering your input and making my own decisions. If I diverge from your chosen path, please don’t be offended.

Regarding filter/booster interference... Yep, it’s going to be squeezy, which is why I ordered the 75mm trumpets and not the 100mm jobbies (which would be better from an inlet flow tuning point of view). I’m expecting to have to move my Wilwood brake bias valve to make as much room as possible (custom brake lines required, probably).

Regarding ITB’s versus OEM manifolds... Yep, you’re probably right.... Lotsnof trouble for little gain. I was given an ITB recipe that I liked the look of, which is not stupidly expensive and involves a level of challenge that I am willing to take on. Maybe it’s unnecessary and even unwise, but I’m going for it anyway. And yes, I’m excited about the unique sound that they will produce, and I’m hoping that they yield more power, somewhere. If not, well I can always sell them and do something else. As with any car mod, it probably won’t be the final iteration.

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Magpie · Postby **Magpie** » Fri Aug 30, 2019 7:44 pm

Scoota wrote:Please don’t get the impression that I’m ignoring your advice. I’m considering your input and making my own decisions. If I diverge from your chosen path, please don’t be offended.

Your car your money your decisions

100mm trumpets are possibly still too short, but they will make a massive improvement in mid range over 50mm ones.

As mentioned, you may need to move the clutch master as well. This can be achieved by utilising the brake master and drawing fluid from there to the clutch with a hard line. I did this on mine for a while, it works.

Instead of the filters you are looking at consider something like a Pipercross setup and you can offset the trumpet holes a bit to move the filter towards the front of the car. This was done on mine when it was first built with ITB's.

The 'best' solution if running ITB's is to get rid of the brake booster, however this needs to bone with a bit of thought to pedal ratio and effort required. Mine has a modified pedal and some people are still surprised at how much effort is required to cause brake lock up. They have sat in the car and pushed on the pedal until the brake pressure sensor says about 600psi. What you will get from this is a linear brake pedal, how hard you press is how fast you stop...

Photo of John Pham's setup

John's half size radiator

This was sent to me last year and it is still something I enjoy listening to
https://www.facebook.com/kevinvinall/videos/10157896322373065/

Scoota · Postby **Scoota** » Sat Aug 31, 2019 9:02 pm

Hey Magpie, thanks for the info.

Regarding the foam filter from Pipercross, I’ll check it out. Thanks for the tip.

Regarding your suggestion about using the brake master cylinder to supply the clutch... Very interesting!!! I think I might get in touch with you when I’m ready to look at that particular mod. Would you mind?

Regarding deletion of the brake booster...
I have to admit, it’s not my first preference. A pedal box would be a neat solution, but I’m not ready to dive into that at the moment. I already have enough on the go!

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Magpie · Postby **Magpie** » Sat Aug 31, 2019 11:00 pm

Scoota wrote:Would you mind?

No problems, I have posted it on the forum here, just need to find it.

Due to a crash on the forum some time ago, old posts cannot be searched

Scoota · Postby **Scoota** » Sun Sep 01, 2019 7:14 am

Sweet, thanks Magpie.

Hey, here’s a question for everybody...

Has anybody created a cold air chamber for their ITB’s? I’m not a huge fan of having the intake breathing directly from the hot engine bay.

Suggestions anyone?

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Tim_cyc03 · Postby **Tim_cyc03** » Sun Sep 01, 2019 11:35 am

Scoota wrote:
Has anybody created a cold air chamber for their ITB’s? I’m not a huge fan of having the intake breathing directly from the hot engine bay.

There is a whole thread on that in the ITB part of the forum. 9 pages worth to be precise.

Scoota · Postby **Scoota** » Sun Sep 01, 2019 6:41 pm

Ah, thanks Tim. I’ll check it out.

That’s a perfect example of “You don’t know what you don’t know”, and a perfect illustration of how valuable this forum can be.

Cheers!

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The American · Postby **The American** » Mon Sep 02, 2019 8:26 pm

My 2c:
Your number one challenge will be getting this all assembled, running, tuned and debugged by the end of November. If you want to do that event, just swap the new engine in and run it as stock as you can. There’s eons if tinkering in the rest of the mods (or buckets of cash).

Red_Bullet · Postby **Red_Bullet** » Mon Sep 02, 2019 10:12 pm

The American wrote:My 2c:
Your number one challenge will be getting this all assembled, running, tuned and debugged by the end of November. If you want to do that event, just swap the new engine in and run it as stock as you can. There’s eons if tinkering in the rest of the mods (or buckets of cash).

Yep, an MX-5 should be a long love affair. Can't be rushed.

1600Dave · Postby **1600Dave** » Mon Sep 02, 2019 11:33 pm

The American wrote:My 2c:
Your number one challenge will be getting this all assembled, running, tuned and debugged by the end of November.

And logbooked - I'm sure you're all over it, but if its track only (ie not road reg'd), it will need to be CAMS logbooked for Challenge Bathurst.

Red_Bullet · Postby **Red_Bullet** » Tue Sep 03, 2019 10:39 am

Magpie wrote:
Scoota wrote:Would you mind?
No problems, I have posted it on the forum here, just need to find it.

Due to a crash on the forum some time ago, old posts cannot be searched

Consider using "google advanced search" that finds old threads.

https://www.google.com.au/advanced_search