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Old 08-01-2013, 10:57 AM   #61
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what kind of knock sensor would you recommend?
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Old 08-01-2013, 11:18 AM   #62
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i want a turbo ive got itbs stuff.
This changes everything. If you want turbo + pump gas + reliability you want 8.6:1. You will also get the benefit of making more power with that than a higher comp.

So are you going turbo or staying NA?
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Old 08-01-2013, 11:44 AM   #63
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Little motors are far more knock resistant to big motors.
Yep, smaller bore makes it easier to control the flame front.

Look at sport bikes that run 13:1 on 91 with speed density systems, or the Coyote engine mustang's for instance that can run perfectly fine on 87 with 11:1 compression. There is only an 8hp difference between 87 and 91 according to Ford.

If E85 was more readily available in my area, when I build an N/A 1.8 next year, I'd be looking at 13:1+
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Old 08-01-2013, 12:19 PM   #64
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I have 12:1 pistons in my car. At first I ran a blend of race and pump gas. After I got used to tuning it a while I took it down to pump gas.
What cams are you running?
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Old 08-01-2013, 12:44 PM   #65
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Quote:
Originally Posted by Full_Tilt_Boogie
What cams are you running?
Let me whip out my cam card for you.

valve lift is .370"/.370"
advertised duration is 237*/237*
duration @ .050 is 214*/214*
lobe center is 111*/111*

It is not a whole lot bigger than a 99 or later vvt cam.
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Old 08-01-2013, 01:10 PM   #66
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Hmmm
Sounds like a good grind. All around a little hotter than VVT cams.
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Old 08-01-2013, 02:10 PM   #67
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Originally Posted by miata2fast View Post

I have 12:1 pistons in my car. At first I ran a blend of race and pump gas. After I got used to tuning it a while I took it down to pump gas. Never had a problem with det, and I visually inspected the pistons numerous times. Little motors are far more knock resistant than big motors. Take the advice from someone who has done it.
You have reverse flow cooling with an electric water pump. And your larger cam knocks the mechanical compression down a little. Not exactly the same...
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Old 08-01-2013, 03:34 PM   #68
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You have reverse flow cooling with an electric water pump. And your larger cam knocks the mechanical compression down a little. Not exactly the same...
Steve, you have to consider that I ran the motor like that for years without the water pump. The pump was on there for one hard night at the dragstrip, and maybe a five hundred miles on the road. I made a few hundred passes at the drag strip before the pump. The cam is just a tad bigger than stock, and it is a full point higher in compression than the 11:1 I recommended. So I still stand by my logic that 11:1 is childs play.
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Old 08-02-2013, 04:35 AM   #69
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Default ITB's, my .02

ITB's, I like 'em. Coming from the motorcycle industry where everything fast has them, they're fairly simple and straightforward.

So instead of forced induction, ITB's are used with a higher compression ratio, bigger cams and rpm's to make power. As such, an aftermarket ECU only makes sense. Also, put me in the camp who thinks that 10.5:1 compression on premium gas is no problem at all.

There's something inherently "right" about an inline 4 iron block with ITB's. it's like the better version of carbs. Make mine with a top mount shower/fogger.
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Old 08-03-2013, 01:07 AM   #70
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Default ITB refresh

Here are some before and after pictures of a Black top ITB rebuild with Techno Toy Tuning intake manifold.
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Old 08-03-2013, 01:48 AM   #71
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Here are some before and after pictures of a Black top ITB rebuild with Techno Toy Tuning intake manifold.
How well does your techno tuning mani fit? Mine is pretty tight on the studs.
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Old 08-03-2013, 02:28 AM   #72
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How well does your techno tuning mani fit? Mine is pretty tight on the studs.
Right now my ITB setup is jewelry...it sits on the shelf looking good. I've heard that about the TT manifold. If I had a complaint, it would be that the stuff is not exactly feather weight; It needs a few more passes under the mill. I understand that extra CNC time means more expense, but this stuff hangs off the engine far enough that I'd like to minimize the weight.
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