8 Throttle Body Intake

[Ghazzah]

Thanks for the advice, Guys. Re-reading my Microtech manual for the 10th time in preparation.

Gaz.

 

[BARRY]

when using a map sensor load based fueling map anything over 5% throttle will show 80% as what would normally show if the car was not ITB.

so basically you are almost maxing out your map sensor voltage at only 5% voltage. sure map sensor maping is good for low speed low throttle driving, but anything involving acceleration you will always be over rich or over lean.

with tps mapping your are exact to the dot for an itb setup.

 

[Damien]

Using both and blending them would be the best option but AFAIK only Autronic and Motec can do that.

 

[rivmasta]

All EMS units can use both and blend as well, though at <3% it uses only TPS.

 

[Ghazzah]

Microtech Man tells me to vent the MAP vacuum line to the engine bay and forget it. he states that 'When you move to TPS based mapping you won't believe the difference in response over MAP-based mapping.

Anticipation.....

 

[rivmasta]

Arghhh! block it off! dont vent it! If its NA you'll suck dirty air, if its FI you'll lose boost! Seal it off if you're not going to use it!

*edit* this is the line out of the plenum mind you, not out of the ECU if its got its own vac line. *edit*

 

[BARRY]

lol...

they tell you to vent it because it will now be used as a barometric correction map. AKA altitude correction.

tps mapping is super responsive compared to map sensor setup for racing applications on an ITB car. fuel economy definately is off compared to a manifolded map sensor car, but you cannot compare race to stock. you modify your car to run better and make more power at given costs.

 

[Ghazzah]

Fuel economy has never been a consideration....

I have a 4:1 differential and a poor 5th gear ratio in the 'box, which gives AWESOME acceleration but places the revs at around 3500rpm at 100kmph...

Best economy to date has been around 20mpg (Imperial gallons) on the open road at steady cruise.....worse effort was ... 4mpg at the local track. Yep. 4. Four. Quattro.

;-)

 

[Peewee]

I didn't think it was possible for the 1UZ to use that much fuel.

When I first got my Microtech ECU I drove around for a couple of weeks on the base tune.
She got 9mpg on the road.
I'm sure I could have got that down to 6 on a track, but I dunno about 4.

US Gallons there, so 3.78:1

11mpg @ 4.5:1

 

[Ghazzah]

4mpg. Yep. Achieved. Couldn't believe it myself so rechecked all figures twice. Remember that this is on a tight 3km race circuit with full-throttle around 75% of the lap (and several rather stupid long revlimit-bouncing smokin donuts in the pits. 750m back straight with indicated speed of 200+kmph coming off a sweeping hairpin, not too bad for a wee 4 litre japper, eh? Ended up going backwards down the track several times after overcooking it a bit in the infield...at around 120kmph, so whacked it into 3rd, and nailed it, back tyres smoking, car slowing, still pointed the wrong way, into 2nd, nailed it, smoke, into 1st and full lock, smoky 180 burnout and off we go again. Many a cheer from the pit wall! Yep, 4mpg is doable with this sort of treatment (and broken gearboxes, but that is another story...)

1 Imperial gallon = 4.54 litres.

MPG to Km/L factor of 2.83. Soooooo, I guess that equates to 1.41km/l?

A good swift drive around the local mountains gives between 12-16mpg.

G.

 

[ed_ma61]

finally managed to download some images off my mobile phone. plus the bottom one is an extra i havent posted yet.

manifold is currently half welded together (waiting for jase to get back from holidays!) nellmouths arent that long - about 30-35mm total height...

 

[Ghazzah]

Wicked. Will look awesome when finished, Bro.

My ITBs are just about finished. Working on laser cutting mounting brackets for the Summit fuel rails at present, but apart from that all set to go. The calculations for the throttle linkages were a nightmare, but got it sorted. Difficult to get a linear relationship between banks. Zero-backlash helical couplings used between the throttle shafts. $ but wicked. 3rd mortgage to get everything polished.

http://s62.photobucket.com/albums/h...rent=P101028330.jpg&refPage=&imgAnch=imgAnch7

http://s62.photobucket.com/albums/h...t=EP101028730-1.jpg&refPage=&imgAnch=imgAnch6

http://s62.photobucket.com/albums/h...ent=P101034230.jpg&refPage=&imgAnch=imgAnch18

http://s62.photobucket.com/albums/h...P1010358Open30.jpg&refPage=&imgAnch=imgAnch14

Off topic a bit, but finishing off the ground effects undertray and brake cooling ducts. Undertray, front splitter and rear diffuser work 100%, as the steering gets heavier and the car tracks straight-as above 200kmph now instead of jumping nervously all over the show:

http://s62.photobucket.com/albums/h...rrent=P1010405E.jpg&refPage=&imgAnch=imgAnch9

http://s62.photobucket.com/albums/h...rent=P1010402E.jpg&refPage=&imgAnch=imgAnch10

http://s62.photobucket.com/albums/h...rent=P1010397E.jpg&refPage=&imgAnch=imgAnch12

http://s62.photobucket.com/albums/h...rent=P1010395E.jpg&refPage=&imgAnch=imgAnch13

http://s62.photobucket.com/albums/h...ent=EP101017535.jpg&refPage=&imgAnch=imgAnch5

...and just in case you chaps think that we Kiwis are a bunch of pussies, here is a pic of a typical Christchurch winter's day. Open top motoring in this weather? Go hard or go home! Went out the other day in -3 degrees Cel ambient.....mad.

http://s62.photobucket.com/albums/h...=EP1010256small.jpg&refPage=&imgAnch=imgAnch1

http://s62.photobucket.com/albums/h...=EP1010274small.jpg&refPage=&imgAnch=imgAnch2

Gaz.

 

[Damien]

Gazzah, I got some of those helical couplings for my setup after seeing yours and they're fantastic! Bit pricey but luckily I only needed 2. I was having issues with bind-up between adjoining throttlebodies as the couplings I had clamped them together with no flexibility.

 

[turboteener]

Mind if I ask why you didn't do a simple bell crank in the middle so that both pairs open in the same direction. Like the old school Weber setups.

 

[Ghazzah]

Good question.

1. Didn't think of it.
2. Other people are doing it.
3. Too easy.
4. I think they are a bit ugly.
5. Didn't think of it.

;-)

G.

 

[cribbj]

!@#$% Butterfly Screws

Love the look of powder coated TB's, but I hate disassembling the TB to do it, especially removing those blasted butterfly screws.

Has anyone done it without mangling those screws or the throttle shaft? The screws are brass or other very soft metal, and have been peened so they won't accidentally back out.

The only way I've done it in the past is to drill the suckers out, then replace them with larger screws when I'm done.

Someone have a better way?

 

[Ghazzah]

We simply used a red 2-pak on the bodies, and while we did remove the butterflies, it would be possible to leave your butterflies in place, do some very careful masking, and get the bodies painted and baked in a heat box.

Very difficult/impossible to remove those pesty little butterfly screws and then reuse the OEM throttle shafts.

We drilled out the original shaft screws (lots of care not to munt the soft, soft butterflies), and we had new throttle shafts made up and black anodised, new small machine screws lock-lighted in securely (don't want these little bastards dropping into the engine at 7000rpm...)

I am lucky that the chap helping me is the foreman of a CNC machine shop....it helps!

Lots of work, but a beautiful result.

Stick with it.

Gaz.

 

[cribbj]

I'm really tempted to try leaving the shafts & butterflies in place and do a test run on 1 TB.

I was actually more worried about the shaft seals deforming from the heat, than anything else. If I bugger one up, it's not a complete disaster.

Did your shop do a bead blast for the surface prep, or just chemically clean them?

 

[Ghazzah]

Just a simple chemical clean, not sure what they used, but nothing special and nothing harmful to seals etc.

We didn't use too much heat, I think the spray booth was around its normal 60 degrees or so, your engine bay gets hotte than this.

Do it.

 

[cribbj]

60 C? So you must have painted the TB's?

I mistakenly thought you'd powder coated them! Powder coating needs around triple or quadruple that temperature, correct?