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View Full Version : I finished my intake.......again



fishcleaner
05-29-2011, 11:05 PM
I'm finally back working on my car. I made an intake awhile ago but it ended up a little too tall so I chopped it 3/4" and hopefully it will fit, I have no way of telling until the motor goes into the car. It's made with 2" aluminum elbows which is the O.D. of the lower half of the 2 piece intake tubes, it worked out nice. The throttle body mount is a for 65mm Edelbrock unit.

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GLHNSLHT2
05-29-2011, 11:57 PM
cool.

boost geek
05-30-2011, 12:19 AM
Looking good! Sure a 65mm tb won't be overkill?

fishcleaner
05-30-2011, 09:43 PM
I'm not sure about anything on this build, its all un-charted territory for me, my logic was V8 HP = V8 throttle body. I will be modifying the throttle cable cam so the tip in will be more gradual.

tkelly27
06-05-2011, 01:23 AM
For some reason people are afraid of big throttle bodies in the dodge community. DSMs come stock with 60mm with no issues. I think the people that had problems in the past with 52mm units weren't doing it right.

Your intake looks really good!

BadAssPerformance
06-05-2011, 09:32 AM
For some reason people are afraid of big throttle bodies in the dodge community. DSMs come stock with 60mm with no issues. I think the people that had problems in the past with 52mm units weren't doing it right.

Your intake looks really good!

Either that or the strong desire in the community to do it with stock parts? I agree, no reason to be afraid of a bigger TB when used properly

You mention DSM's... I remember years the first time I hear stock long block N/A civic was using a 60mm TB... Really? and its almost 6 secionds slower then my (then quick) 13.00 car on a 52mm.... wait a minute, its bigger but just not using it... OK... thats the equation, how much is needed... When i put the 2.4L in the Z I put a 75mm on it.... probably isnt using all of it? But I should be good for not having to upgrade.

+1 Nice work fishcleaner!

cordes
06-05-2011, 06:04 PM
What's the plenum volume on that?

Juggy
06-06-2011, 02:52 AM
nice job!

Ondonti
06-06-2011, 06:11 AM
N/A and turbo TB requirements are nothing alike.

Hondas are running twin 100mm TB's in the top hp n/a cars. They do that because they are still measuring tiny amounts of vacuum when they go smaller.
I believe when the King of the street H series went from a 105mm to twin 90's with an even bigger plenum he gained 40whp. He still measured vacuum so he went twin 100 something. His car weighs 2400 pounds and run's 10's n/a....and he can't hang with the K series guys.



The throttle cam I did for my 58mm is almost too much. It does make throttle modulation very easy at low throttle. It actually feels the same way as lag. I keep expecting more power then what happens at low throttle, then I overcorrect. Still getting used to it. It creats less control at large openings but usually 75% throttle is almost the same as 100% when it comes to airflow. Only difference is how our OEM computers deal with it.

fishcleaner
06-07-2011, 02:17 AM
What's the plenum volume on that?
I'ts a little over 2 liters, not much room to go too much bigger

The throttle cam I did for my 58mm is almost too much. It does make throttle modulation very easy at low throttle. It actually feels the same way as lag. I keep expecting more power then what happens at low throttle, then I overcorrect. Still getting used to it. It creats less control at large openings but usually 75% throttle is almost the same as 100% when it comes to airflow. Only difference is how our OEM computers deal with it.
I found that out the hard way about the throttle cable cam. I installed a TBI on a '73 Cuda and the drive ability went down, drove me nuts trying to diagnose it, then I figured it out and it ran good.

I finally bolted it on for good (I hope)

http://www.crazy4carz.com/gallery2/d/67153-1/intake+back.jpg

RoadWarrior222
06-07-2011, 11:30 AM
I think the TB issue is the specific ones people have tried. For instance the mopar 58mm unmodified, should work fairly well, but it has been observed that when bored out, or "ported" it actually flows less than at stock, some people have modded them without trying them stock, this might have given rise to the myth that 58 and above is not worth the hassle, or doesn't work well. Then another popular "mistake" is ford 5.0 TBs, which don't seal well at the plate when closed, and have funky idle air setups (For tryna control them with what we've got) so those seem to idle like arse and have on/off style "tip-in" which don't make for driveability.

Vigo
06-07-2011, 08:15 PM
V8 HP = V8 throttle body

That simple logic i believe is actually more correct than most of the stuff people spew on that subject. I think the issue with the TM community is that people dont understand that the TB shouldnt (or no reason to) be noticeably bigger or smaller than the flow patch directly in front of or behind it. Because you have a custom plenum, you actually have the option to use/benefit from a bigger TB than most people on this forum.

Vader85
06-09-2011, 09:14 PM
That sure is nice!

Sundance 6g72
01-10-2012, 10:23 PM
Either that or the strong desire in the community to do it with stock parts? I agree, no reason to be afraid of a bigger TB when used properly

You mention DSM's... I remember years the first time I hear stock long block N/A civic was using a 60mm TB... Really? and its almost 6 secionds slower then my (then quick) 13.00 car on a 52mm.... wait a minute, its bigger but just not using it... OK... thats the equation, how much is needed... When i put the 2.4L in the Z I put a 75mm on it.... probably isnt using all of it? But I should be good for not having to upgrade.

+1 Nice work fishcleaner!

remember, that civic is reving alot higher then most other cars... combined with variable cam it can suck in alot of air up in the revs and requires a big exhaust and intake even if its N/A

i like this intake, looks grea. hope it fits

RoadWarrior222
01-11-2012, 08:10 AM
Or yer empirical way of thinking about it, an N/A 4 banger at 10,000 is gonna want about as much air as a V8 at 5,000

But then your problem in a DD, is that a 4banger will run 1500 RPM on a TB that idles a V8 at 750... so I'd be thinking of sleeving the idle passage straight off.

turbovanmanČ
01-11-2012, 01:40 PM
Either that or the strong desire in the community to do it with stock parts? I agree, no reason to be afraid of a bigger TB when used properly

You mention DSM's... I remember years the first time I hear stock long block N/A civic was using a 60mm TB... Really? and its almost 6 secionds slower then my (then quick) 13.00 car on a 52mm.... wait a minute, its bigger but just not using it... OK... thats the equation, how much is needed... When i put the 2.4L in the Z I put a 75mm on it.... probably isnt using all of it? But I should be good for not having to upgrade.

+1 Nice work fishcleaner!

How do you figure out what size to use or how to figure out if you went too big?

Ondonti had a thread up about N/A Honda's, guy was running a 60+ mm and he was getting vacuum at WOT so he went even bigger, it was a 10 sec car, :nod:

BadAssPerformance
01-11-2012, 02:36 PM
remember, that civic is reving alot higher then most other cars... combined with variable cam it can suck in alot of air up in the revs and requires a big exhaust and intake even if its N/A

True...


How do you figure out what size to use or how to figure out if you went too big?

Gotta calculate CFM capability of the engine at RPM and go from there

RoadWarrior222
01-11-2012, 02:40 PM
Ondonti had a thread up about N/A Honda's, guy was running a 60+ mm and he was getting vacuum at WOT so he went even bigger, it was a 10 sec car, :nod:

BTW anyone running any kind of airfilter will measure vacuum at WOT whatever TB they put on it... that's just before you run out and go, "Noes, I have a tenth of an inch of vacuum at WOT on my DD!!!111oneone Needz moar throttle body!!!111oneone"

zin
01-11-2012, 04:35 PM
BTW anyone running any kind of airfilter will measure vacuum at WOT whatever TB they put on it...

Very true, which is why you need to measure pressure differential on either side of the restriction (Throttle Body in this case).

IF there is a significant pressure drop, lessen the restriction (larger TB).

As for the drive-ability, there are a couple of tricks that can be done. The best is a staged TB, typically a smaller blade is used in the flow zone that DD would take place, with the secondary/larger blade coming on somewhere in the 1/2 throttle area and progressing to full open in sync with the primary blade. VWs and Audi have them most commonly, but they've been used on lots of other stuff too, the original ZR-1 had a three bladed TB, the primary was a tiny one, but it did the job...

The other trick, which is much more common (read cheaper!) is to shape the cable pull "cam" in a way that adjusts the way the TB opens to suit the engine/driver. Basically, you can shape the cam "lobe" that the cable rides in to be aggressive (like many imports do to make the engine feel stronger) where you get a lot of throttle for relatively little pedal, or make them slow, to lessen the surge you might get from a larger engine with lots of vacuum, and/or only allow a small amount of throttle to be used in "normal" driving.

Incidentally, this is one of the feature/reasons why most automakers have gone "drive by wire", they can simply program a curve to give the desired feel, and even better, re-program it latter to better suite the public or more likely, correct for EPA mandates.

Mike

PS I've acquired a few of the staged TBs, but have yet to flow them, so I don't know how appropriate they'll be for our applications, but I have a good feeling about them, even if they will likely require a custom intake...

fishcleaner
01-12-2012, 02:09 PM
The other trick, which is much more common (read cheaper!) is to shape the cable pull "cam" in a way that adjusts the way the TB opens to suit the engine/driver. Basically, you can shape the cam "lobe" that the cable rides in to be aggressive (like many imports do to make the engine feel stronger) where you get a lot of throttle for relatively little pedal, or make them slow, to lessen the surge you might get from a larger engine with lots of vacuum, and/or only allow a small amount of throttle to be used in "normal" driving.
That's the road I took, the way I made the throttle cam, I can rotate it to get the right feel. I put a TBI system on a 340 Cuda many years ago and the car wasn't drivable until I figured that out. I'm getting really close to firing this thing up, probably sunday will be the big day, will let you know how it works out.