How to build ITBs - Page 4 - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

StegaDragon · 12-04-2015, 09:14 PM

Quote:

Originally Posted by celek

Here is one possibility

Sorry thought you were talking about this kind of set up that doesn't use a single plenum for the TBs

SC10N driver

wparsons · 12-05-2015, 09:21 PM

Quote:

Originally Posted by celek

exactly a very large plenum, what else would go in the middle of the engine

It would need to be a HUGE plenum to get short runners to the two heads.

Remember that the boxer engines are much wider than a V engine, and the V engine has the intake ports MUCH closer together (between banks) than a boxer.

Spartarus · 12-05-2015, 09:41 PM

The alternative, rather obviously, is 1 plenum per bank, with a dual MAF setup. Many cars (e39 M5, B7 RS4) have made dual-MAF work.

You could run the intake snorkels over the top of the radiator like stock, or down to the fog light cavities.

celek · 12-07-2015, 09:55 AM

Quote:

Originally Posted by wparsons

It would need to be a HUGE plenum to get short runners to the two heads.

Remember that the boxer engines are much wider than a V engine, and the V engine has the intake ports MUCH closer together (between banks) than a boxer.

Not a problem

celek · 12-07-2015, 09:57 AM

Quote:

Originally Posted by Spartarus

The alternative, rather obviously, is 1 plenum per bank, with a dual MAF setup. Many cars (e39 M5, B7 RS4) have made dual-MAF work.

You could run the intake snorkels over the top of the radiator like stock, or down to the fog light cavities.

now you are on my same thinking path

celek · 12-07-2015, 05:28 PM

It's here. Now to cut it up.

Turdinator · 12-07-2015, 09:17 PM

Quote:

Originally Posted by Spartarus

That's the only practical way to use MAF with ITB.

I have never seen MAP-based speed-density work right with ITB's. You lose all your vacuum above about 40% throttle.

The smoothest running ITB setups (without a plenum) I've seen and worked nearby are all on a high-resolution alpha-N map where the primary inputs for fueling are throttle position and RPM. Significant corrections include ambient temp/pressure, wideband closed-loop at low throttle settings, and very thorough tip-in and overrun corrections.

Getting them to idle is harder than tuning them to run.

There are some ECUs that can run a blended MAP and Alpha-N setup, so that you get the low speed drivability and idle quality of the MAP setup but can still get the high load tunability of the Alpha-N.

solidONE · 12-08-2015, 03:01 PM

Well alright! subbed

celek · 12-11-2015, 09:16 PM

Back from PRI has a good conversation with Borla on how to approach this.

Gear_One_Performance · 12-15-2015, 04:43 PM

Are you planning on using off the shelf throttle bodies and adapting to them or machining your own?

Hyper4mance2k · 12-15-2015, 07:36 PM

/endthread

Killianti · 12-15-2015, 08:04 PM

Quote:

Originally Posted by Hyper4mance2k

/endthread

So throttle! Much wow! Very power!

Hyper4mance2k · 12-15-2015, 08:15 PM

Quote:

Originally Posted by Killianti

So throttle! Much wow! Very power!

Eventually I'm going to put 2 Gene Berg carbs on a F20.
I've been tuning down draft IDA style carbs for over a decade. Nothing builds a relationship with your car than going outside and optimizing it for that day's weather.

edit: or this thing is going to get a 13B bridgeport swap. 300whp NA should do me just fine.

Calum · 12-16-2015, 06:03 PM

Quote:

Originally Posted by celek

Back from PRI has a good conversation with Borla on how to approach this.

I'm surprised by this. Does Borla have a back ground in such things? The only things I've ever seem from them are cheap exhaust parts.

*serious question.

12-05-2015, 09:41 PM	#45
Spartarus ...Just add nauseum Join Date: Jan 2015 Drives: 2003 (AP1) S2000 Location: Miami, FL Posts: 546 Thanks: 310 Thanked 785 Times in 335 Posts Mentioned: 19 Post(s) Tagged: 1 Thread(s)	The alternative, rather obviously, is 1 plenum per bank, with a dual MAF setup. Many cars (e39 M5, B7 RS4) have made dual-MAF work. You could run the intake snorkels over the top of the radiator like stock, or down to the fog light cavities. __________________ There are many ways to displace. -Spartarus

12-08-2015, 03:01 PM	#50
solidONE Senior Member Join Date: Dec 2012 Drives: FR-S Whiteout Location: California Posts: 2,863 Thanks: 1,808 Thanked 791 Times in 611 Posts Mentioned: 42 Post(s) Tagged: 0 Thread(s)	Well alright! subbed __________________ Intent > Content cowardice is the mother of cruelty.

12-15-2015, 07:36 PM	#53
Hyper4mance2k Alexandrino_Auto Join Date: Apr 2014 Drives: series.Blue Location: Greater DMV Posts: 1,014 Thanks: 1,584 Thanked 637 Times in 377 Posts Mentioned: 10 Post(s) Tagged: 3 Thread(s)	/endthread Attached Images

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Beginner STX Build Whiteout FRS Build Thread	Hachi86Roku	Tracking / Autocross / HPDE / Drifting	21	03-31-2020 08:52 PM
[B is for Build] BRZ resurrection build	im_topher	Member's Car Journals	49	03-05-2018 10:41 AM
No build date on passenger side sticker, how to determine build date?	BBYZILA	Scion FR-S / Toyota 86 GT86 General Forum	5	01-20-2015 11:14 PM
Dat sound - ITBs	RWD_only	Engine, Exhaust, Transmission	88	11-18-2014 05:19 PM
20v ITBs	Nafe	NEW ZEALAND	4	05-20-2014 09:03 AM

12-15-2015, 04:43 PM	#52
Gear_One_Performance Senior Member Join Date: Mar 2015 Drives: 2014 BRZ SCCA STU endurance car Location: West Chester, Pennsylvania Posts: 199 Thanks: 2 Thanked 142 Times in 82 Posts Mentioned: 1 Post(s) Tagged: 1 Thread(s)	Are you planning on using off the shelf throttle bodies and adapting to them or machining your own?

User Name		Remember Me?
Password