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View Full Version : Quad Throttles What Are The Gains??



Beechy
05-11-2011, 02:28 PM
Are Quad Throttle worth buying like r there big power gains??

TODA AU
05-11-2011, 03:41 PM
Are Quad Throttle worth buying like r there big power gains??

If you've already got cams, compression, capacity, etc, then yes...
They are worth it.
But only when used with an airbox.

Gains are (B18C) 35hp @ 5500rpm & 10hp top end.
- Vs Itr manifold & 65mm throttle.
- No change to port shape.

Change the port shape together with clever portwork,
You can see an extra 50hp @ 6000 & 40hp top end.
But if you've got a low budget shitter, don't waste your time.

Bludger
05-11-2011, 03:45 PM
^^

what he said.

u mad?
05-11-2011, 04:29 PM
If you've already got cams, compression, capacity, etc, then yes...
They are worth it.
But only when used with an airbox.

Gains are (B18C) 35hp @ 5500rpm & 10hp top end.
- Vs Itr manifold & 65mm throttle.
- No change to port shape.

Change the port shape together with clever portwork,
You can see an extra 50hp @ 6000 & 40hp top end.
But if you've got a low budget shitter, don't waste your time.

Wow thats a massive increase in midrange!

trism
05-11-2011, 05:12 PM
also good for throttle response.

dougie_504
06-11-2011, 06:30 AM
If you've already got cams, compression, capacity, etc, then yes...
They are worth it.
But only when used with an airbox.

Gains are (B18C) 35hp @ 5500rpm & 10hp top end.
- Vs Itr manifold & 65mm throttle.
- No change to port shape.

Change the port shape together with clever portwork,
You can see an extra 50hp @ 6000 & 40hp top end.
But if you've got a low budget shitter, don't waste your time.


What kind of compression and capacity would you recommend?

Bludger
06-11-2011, 08:48 AM
Capacity should not matter. But will amplify the effectiveness of your modifications.

Compression - as high as you can live with....

pat88c
06-11-2011, 05:13 PM
What kind of compression and capacity would you recommend?

Would have to be anything over 12.5 to 1and higher compression

u mad?
06-11-2011, 05:18 PM
Would have to be anything over 12.5 to 1and higher compression

surely you wouldn't need a comp that high to see the benefits of itb's?

pat88c
06-11-2011, 05:31 PM
Stock B18c type r has about 11.1 to 1

What need to make power cams, compression, fuel and air flow
Most race cars run anything from 12.1 up 15.1 and some of turbo setup i seen running around at the drags run 12.5 to comp plus 20 psi boost

trism
06-11-2011, 07:45 PM
yeah, but doesnt mean you ned massive comp ratio to get any benefit. Just means the higher it is, the more youll get out of it.

Fraser
07-11-2011, 01:09 PM
There are some on ebay,they previously reached $600 plus and have since been relisted so obviously the owner didn't get what he wanted at that price.Can get them new for $900.Too much hassle without a cold air box but better than nothing.K series would be trick though.The thought went through my head as I have a K without an inlet manifold.

GSi_PSi
07-11-2011, 03:06 PM
ITB's provide great midrange hp/torque, ie imo great for tracking the car.
For Overall Peak power a Edlebrock Intake manifold+Cold Air Fed Airbox Combo will come out on top vs ITB's

trism
07-11-2011, 03:30 PM
Heres a quick thing about temps.

When i had my corolla, AE92 with a 20v Blacktop 4AGE, factory quads for those who dont know, i decided to do an experiment.

in the height of summer, mid December, i got myself one of these

http://www.instrumentchoice.com.au/images/productimages/Environment_Meters/IC0116.gif


literally that exact one. its got a temp sensor in it, and one of a 2m long lead, so you can get outside and inside car temps.

What i did, was i took the plenum chamber/airbox off, so it was running open trumpets, pointed at the firewall, and i got the temp sensor, and i mounted it, so it was hanging off the strut brace, right where they drew the air from.

ambient temp was about 35 degrees, the sensor under the bonnet was reading off the scale, maxed it out at like, 70degrees.

so i put the plenum back on, and ran a pipe straight from it down to under the front bar, pointing forwards., with the sensor suspended inside the plenum.

i was seeing temps of 30 degrees. It woulda been showing under ambient because the air rushing past the sensor, so the engine was drawing ambient air. Thats a massive difference, and something i tell people every time i see them with open ITBs.

The best part was the winter test but. Same set up, under bonnet temps were about 50degrees, but the shocking part was with a full intake, drawing fresh air, ambient temp was 12 degrees, the sensor was reading 5degrees!

And at night, i was getting negative temperatures inside the plenum. That is some seriously dense air!

point being, as much as ITBs may have the coolest sound in the world when run open, it always benefits running an airbox with a proper cold air intake.

dougie_504
09-11-2011, 04:22 PM
So basically any CAI, or enclosed intake + air feed, or ITB's + enclosure + air feed = win?

I always thought so myself, but didn't realise the temperature difference would be that massive.


My mechanic doesn't like the idea of the air-feed at the front of the bumper during summer because he thinks that the bitumen of the road absorbs/releases too much heat which is sucked it at the front of the car. As if that's not better than engine-bay temps...

Bludger
09-11-2011, 04:26 PM
http://www.ozhonda.com/forum/showthread.php?91415-Cammed-Motors-Specs-DYNO-Graph-Mandatory&p=2380387&viewfull=1#post2380387

trism
09-11-2011, 04:56 PM
So basically any CAI, or enclosed intake + air feed, or ITB's + enclosure + air feed = win?

I always thought so myself, but didn't realise the temperature difference would be that massive.


My mechanic doesn't like the idea of the air-feed at the front of the bumper during summer because he thinks that the bitumen of the road absorbs/releases too much heat which is sucked it at the front of the car. As if that's not better than engine-bay temps...

Not just enclosing ITBs, but any intake.

If you have one of these "short ram intake" where the pod filter just sits in place of the factory airbox, youre still gonna be seeing temps that high. A proper CAI, that draws proper fresh cold air, from outside the engine bay is gonna make so much difference.

with regards to too much heat off the road, my tests didnt show shit of a result. Remember, when youre driving along, your constantly moving through the air, its not like youve got a kitchen hotplate positioned under the intake lol

dougie_504
12-11-2011, 12:55 PM
He's old-school and just doesn't like pods IMO.

I'm all for relocating into the hole above wheel well at the very least. Ideally I'd like a fab'd aluminium box so bring the filter closer to the TB though and an air-feed from bumper. Enclosed ITB's would be awesome...mmmm

p3akin
14-11-2011, 05:42 PM
sorry to go off topic but, whats the power/torque difference in the 45mm and 50mm throttle valve??

Bludger
14-11-2011, 06:14 PM
sorry to go off topic but, whats the power/torque difference in the 45mm and 50mm throttle valve??
Length of intake runners dictates what rpm range power band comes on.

p3akin
14-11-2011, 06:54 PM
thanks for that

GSi_PSi
14-11-2011, 08:51 PM
1+ bludger never knew that



You must spread some Reputation around before giving it to Bludger again.

TODA AU
15-11-2011, 05:36 AM
What kind of compression and capacity would you recommend?
Compression – 11.5 : 1 +
Capacity – An increase is helpful but not 100% necessary.
Though you will still have useful gains at std capacity, an increase amplify the result.
My personal favourite is 1979cc B18C – 85.00 bore x 87.2mm stroke


sorry to go off topic but, whats the power/torque difference in the 45mm and 50mm throttle valve??
45mm throttles are better suited to engines with 1600cc to 1900cc
50mm throttles are best suited to engines with approx. 2L capacity over
Smaller throttles offer improved airspeed & better response/midrange


Length of intake runners dictates what rpm range power band comes on.
The following factors interact to dictate the power band & it’s characteristics.
Runner length, plenum/airbox volume, port size & shape, compression ratio, camshaft selection,
Exhaust port size & shape, header selection.
When the combination is correct, then the intake length can be altered with predictable results.
The reverse is true of less than ideal combinations.

The other trap many people fall into is over caming the engine.

Bludger
15-11-2011, 06:06 AM
Compression – 11.5 : 1 +
Capacity – An increase is helpful but not 100% necessary.
Though you will still have useful gains at std capacity, an increase amplify the result.
My personal favourite is 1979cc B18C – 85.00 bore x 87.2mm stroke


45mm throttles are better suited to engines with 1600cc to 1900cc
50mm throttles are best suited to engines with approx. 2L capacity over
Smaller throttles offer improved airspeed & better response/midrange


The following factors interact to dictate the power band & it’s characteristics.
Runner length, plenum/airbox volume, port size & shape, compression ratio, camshaft selection,
Exhaust port size & shape, header selection.
When the combination is correct, then the intake length can be altered with predictable results.
The reverse is true of less than ideal combinations.

The other trap many people fall into is over caming the engine.
"I want the biggest"

lol

lookingforboost
15-11-2011, 06:14 PM
what is the stock stroke on a B18c? and i didnt think you could bore out a B18 that far?

u mad?
15-11-2011, 06:25 PM
45mm throttles are better suited to engines with 1600cc to 1900cc
50mm throttles are best suited to engines with approx. 2L capacity over
Smaller throttles offer improved airspeed & better response/midrange
Is this b series specific? Or can this be applied to k series also? So 50mm for a standard k20a?

Bludger
15-11-2011, 06:37 PM
what is the stock stroke on a B18c? and i didnt think you could bore out a B18 that far?
87.2 is the stock stroke.

compared to b20
89mm stroke
84mm bore.

TODA AU
15-11-2011, 08:57 PM
what is the stock stroke on a B18c? and i didnt think you could bore out a B18 that far?
B18C = 87.2mm / B18A~B B20B = 89.0mm

Use a B18 block with 82.0mm bore & 89mm stroke = 1880cc

Another combo that works well is 81.5mm bore with 95mm stroke - 1982cc
B20A crank / H22A rod / Toda piston. - Rod ratio 1.51:1 / C/R 12.4 without machining
Last one I tuned (like that combo) made 164kw @ the wheels @ 8500rpm (8800rpm rev limit)
The throttle size was 52mm (Jenvey) & it would have likey made better mid range torque with 50's


Is this b series specific? Or can this be applied to k series also? So 50mm for a standard k20a?
Can be applied to K's too....
50's are awsome for 2.0L K20A & 2150cc K20A. (Tim's 12PIN is a good example)
Big K's (2.5L+) that rev would need to be larger

mocchi
05-12-2011, 09:59 AM
any recommended books that discuss this area?