Turbo + ITB's on a miata.
04-18-2010, 07:45 PM
#22
i didnt intend for this to turn into a argument/debate/fight.....
i just wanted it to be a friendly discussion on theoretical pros and cons of doing this. im not telling anybody they should do this or that it is gonna make uber amounts of power gains, this thread was more of a what if.......
i just wanted it to be a friendly discussion on theoretical pros and cons of doing this. im not telling anybody they should do this or that it is gonna make uber amounts of power gains, this thread was more of a what if.......
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04-18-2010, 07:45 PM
#23
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i was thinking what ever size comes on the 4AGE 20v that motor is a 1.6 so it should be okay for the 1.8. alot of people that have done the ITB's on a miata get them off Liter bikes.
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04-18-2010, 07:49 PM
#24
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i can probly get away with choping the flange off a old intake manifold, source the ITBs and make a plenum. it seems simple enough right now...
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04-18-2010, 07:56 PM
#25
i know its not happening right now, i just want it to be ovoided. im gonna do some more research on ITB's and see how cheap i can source parts out for this.
i can probly get away with choping the flange off a old intake manifold, source the ITBs and make a plenum. it seems simple enough right now...
i can probly get away with choping the flange off a old intake manifold, source the ITBs and make a plenum. it seems simple enough right now...
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04-18-2010, 08:01 PM
#27
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thats why i said RIGHT NOW.... lol
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04-18-2010, 11:53 PM
#28
1) Sav has access to parts and services at bigger discounts than the typical enthusiast afaik
2) Your average joe can't cut/weld/fabricate so that 400 price tag would be more like 600. most itb setups I've seen are being sold for 1000 or so.
3) Everyone here has a "guilty until proven innocent" attitude. At least most of us. Sure we're skeptical of new ideas because its much better/easier to use a tried/true method and not **** up our cars.
But hey, when someone shows us proof/results we're more than happy to become believers. At least I am
2) Your average joe can't cut/weld/fabricate so that 400 price tag would be more like 600. most itb setups I've seen are being sold for 1000 or so.
3) Everyone here has a "guilty until proven innocent" attitude. At least most of us. Sure we're skeptical of new ideas because its much better/easier to use a tried/true method and not **** up our cars.
But hey, when someone shows us proof/results we're more than happy to become believers. At least I am
2) Welding I'll agree with, but anyone who can fab up their own DIY turbo setup should have the skills to make the pieces I'm talking about. You then take them to your favorite welder and have him stick then together. Basically you've got to make an aluminum plate with 4 holes in it the shape/size of the ports (plus the thickness of your runner tubes), four short tubes for the couplers from plate to TB, a plenum box, and some misc spacers between the TB's (early GSXR TB's come in paired barrels but they unbolt into separate units). None of it is rocket science and anyone who can run a drill, a file, and a pair of snips could make it with some patience.
3) I know and it's sort of funny because they all also complain about how M.netters won't listen to new ideas... then they do the same thing here.
In my opinion the "idea" of IRTB's and turbos is well enough proven, look at any turbo era inline-4 F1 engine. They pretty much all used IRTB's (mostly slide valve) and made upwards of 1200hp out of 1.5 liters. From my viewpoint it's a question of whether there's enough benefit to be had to make it worthwhile for our level of power. If I were to guess I'd be inclined to say you might notice a difference at about the same point as it becomes useful to ditch the stock intake.
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04-19-2010, 06:00 AM
#31
Like most things having to do with passage of air going into an engine, it depends.
This is stolen from someone who quoted it, on what throttle for horsepower, may or may not be right, seems to make sense to me though:
"...this guide is from A Graham Bell's Forced Induction Performance Tuning:
50mm: 250
56mm: 310
62mm: 390
70mm: 500
75mm :600"
You'd just divide the area of your intended goal by four and choose a width that gives you that opening area. i know you probably know better, but i should remind anyone reading that you'll need to use Area = pie * Radius squared, rather than a linear progression.
Honestly, most any bike throttle body will be good enough, for instance in GSXR's, the 600cc has 38mm, the 1000cc 42mm and the 1300cc 46mm. Believe this is due to keeping air intake velocity down while the bike is under high rev, but don't quote me on this.
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04-19-2010, 08:24 AM
#32
That depends on discplacement and rpm. That is one of the advantages of an IRTB or carb with replaceable chokes. Cast intakes do not have that advantage, so it is impossible to control the speed of intake charge entering the cylinder head with a fixed intake. I currently have 40mm chokes. Forced induction cars use different chokes, but I do not know how to calculate for it.
I would like to add that it depends on what one is doing with the car. I never see IRTBs on the highest horsepower drag cars, but I see them on road race cars. I think, that it has to do with the throttle response advantage IRTBs have, which is not really necessary on drag cars.
I would like to add that it depends on what one is doing with the car. I never see IRTBs on the highest horsepower drag cars, but I see them on road race cars. I think, that it has to do with the throttle response advantage IRTBs have, which is not really necessary on drag cars.
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04-19-2010, 02:42 PM
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You're very welcome.
Like most things having to do with passage of air going into an engine, it depends.
This is stolen from someone who quoted it, on what throttle for horsepower, may or may not be right, seems to make sense to me though:
"...this guide is from A Graham Bell's Forced Induction Performance Tuning:
50mm: 250
56mm: 310
62mm: 390
70mm: 500
75mm :600"
You'd just divide the area of your intended goal by four and choose a width that gives you that opening area. i know you probably know better, but i should remind anyone reading that you'll need to use Area = pie * Radius squared, rather than a linear progression.
Honestly, most any bike throttle body will be good enough, for instance in GSXR's, the 600cc has 38mm, the 1000cc 42mm and the 1300cc 46mm. Believe this is due to keeping air intake velocity down while the bike is under high rev, but don't quote me on this.
Like most things having to do with passage of air going into an engine, it depends.
This is stolen from someone who quoted it, on what throttle for horsepower, may or may not be right, seems to make sense to me though:
"...this guide is from A Graham Bell's Forced Induction Performance Tuning:
50mm: 250
56mm: 310
62mm: 390
70mm: 500
75mm :600"
You'd just divide the area of your intended goal by four and choose a width that gives you that opening area. i know you probably know better, but i should remind anyone reading that you'll need to use Area = pie * Radius squared, rather than a linear progression.
Honestly, most any bike throttle body will be good enough, for instance in GSXR's, the 600cc has 38mm, the 1000cc 42mm and the 1300cc 46mm. Believe this is due to keeping air intake velocity down while the bike is under high rev, but don't quote me on this.
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