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Discussion Starter #1
Hey guys,

First off, I have really enjoyed all the info and insight from this sight. I have had my IS (2002 MSM E-shift) for almost 3 years now and am just getting around to starting a build. I have been following the site for about a year and decided it was time to make an account.

When I first bought the car I installed a K&N with heat shield, Megan axle-back, and Megan Y pipe, as I was looking to get some more out of the higher RPMs. I did notice a decent gain even without an A/F ratio tune. Next on my list is BC stage 2 cams, cam gear, a decent header, followed by an SAFC or EMU to bring it all together.

So I have a question and I want all the input I can get. I want to make the intake system ( From the air being sucked in, down to air entering the head) as efficient as possible, while maximizing the high RPMs. I work in a machine shop and want to tackle either one of two issues through some fabrication and machining. Maybe both if I get bored....

Which of the following do you feel would be a better route to pursue (Remember, I work in a machine shop so possibilities are.......extensive.)

1- Temperature: Ambient air, intake temp, throttle body temp, intake manifold temp.

2- Flow and turbulence: Incoming air to filter, filter tube, throttle body, intake manifold.

I understand that the gains from this pursuit will be maybe a few horsepower and improved throttle response at the most. But I enjoy researching and spending time making things. I have a temp gun and will take some "baseline" temps of different areas under the hood immediately after certain driving conditions. I know just from having my hand on the intake tube and throttle body, they get quite toasty. Whatever route I do go I would love to document and review any gains if there is interest.

Glad to be a MY.IS member!
 

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I would say temeprature would make a bigger difference.

but that's pretty cheap/easy to do in a basic way.....just bypass the coolant on the TB, then a section of carbon fiber fabric over the Header & valve covers & wrap the intake manifold with exhaust wrap or get it ceramic coated.

For improving flow you could make a box that seals from the fender to the edge of the radiator.....if you're willing to tune on a piggy back making a custom intake either 3" for better low-mid or SRT's size for maximum top end(3.5" I think?) would be better than the current K&N. Also 80mm TB & port matching everything for absolutly no restriction.


of course all that AFTER a tune might only get you about 10-15whp(If that) but throttle response should be greatly improved and like you said it's always fun to try new methods
 

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Personally I would attempt an ITB setup if I had the resources
 

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1- Temperature: Ambient air, intake temp, throttle body temp, intake manifold temp.

2- Flow and turbulence: Incoming air to filter, filter tube, throttle body, intake manifold.

But I enjoy researching and spending time making things. I have a temp gun and will take some "baseline" temps of different areas under the hood immediately after certain driving conditions.
I will preface this by stating I have a background in mechanical engineering, with knowledge in both thermodynamics and fluid dynamics. I do not know your background, nor am I poo-pooing your idea.

Heat - Air moving through the intake tract only has a short amount of time to pick up the heat from radiant and convection sources. The heat of the intake manifold is NOT going to be the air temperature. Possibly look into phenolic manifold spacers and a header heat shield. I'm willing to bet this is where you'll find the best results (The 'old' Honda crowd with B-series engines frequently found gains using these)
Magic Ninja edit
: broketuner mentioned ceramic coating. I think this stuff is the cats pajamas and could yield some VERY interesting results in conjunction with reducing the amount of heat the header throws up at the manifold, and with a phenolic manifold spacer.

Flow and turbulence - This is where the voodoo magic of various equations gets thrown around. It's well known that the JoeZ intake pipe is one of (if not the) best options for an intake, while re-using the stock airbox.
For what it's worth, there are dyno documented cases of guys with VW's VR6 engine smoothing the inside of their intake manifolds and loosing power afterwards. Less turbulence isn't necessarily a good thing (reference reading for those who are interested in this, or at least the very beginning of this: Laminar flow - Wikipedia, the free encyclopedia )
Of the two options, I think this one is already the most worked over by various companies.

Hrmm, this was a way longer reply than I expected. But I'm stoked that you are willing to try things out. Remember, buttdyno results are no replacement for the real thing, especially when we could be talking about 2-3 hp here.
 

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Discussion Starter #5
Thanks for the responses!

Broketuner- I like the idea of the SRT. Larger diameter with AFR adjustments. Wish I would have just paid a little extra initially and got one. Maybe I will be able to find one for sale here? Smoothing all the connections in the intake system also sounds like a good idea, as well as the coolant bypass in the TB. I have heard a lot of great things about the Mazzuri and if I could find some on here eventually I will fork the money to get one and get them wrapped up good before install. I could fabricate some sort of aluminum header shield for extra heat protection as well.


Willmkent- If I had the tuning know how I would love to do ITBs... maybe someday;)


Tire marx- Thanks for the input, I do not have any engineering background other than being around engineers all day at work;) I am glad you chimed in. That is really interesting to me that some VW owners had lost power from smoothing the manifolds. I understand that this is mostly beneficial with forced induction as air is being forced through at greater speeds and pressures, but I didn't realize it could actually hurt N/A performance. I am picking up a spare intake manifold this week and instead of port and polishing entire thing, I may just smooth any ridges or bumps and make sure all connections match.


Question for everyone- Headed on an Easter trip this weekend, decided to clean the filter, MAF sensor, intake tube, and throttle body. Noticed while doing this that the throttle plate doesn't seem to get very close to opening up all the way even with the throttle position turned all the way to the max? Seemed a little odd to me that it would be in the position under WOT. Normal?

Thanks again.
 

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Thanks for the responses!

Question for everyone- Headed on an Easter trip this weekend, decided to clean the filter, MAF sensor, intake tube, and throttle body. Noticed while doing this that the throttle plate doesn't seem to get very close to opening up all the way even with the throttle position turned all the way to the max? Seemed a little odd to me that it would be in the position under WOT. Normal?

Thanks again.
We have an electronically control TB, at full throttle the plate should only open a 1/3 of the way. Its the magically DBW that people have asked to delete in the Go faster section.
 

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Heat reducing tape helps , 80 mm TB , coolant line to TB delete/ bypass, gasket match port Y runner and intake manifold. Light weight valves ( upgrade all head components )

Headers help higher rpm band

Cams are the best NA mod

Adj cam gear (-3)
 

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Discussion Starter #8
Heat reducing tape helps , 80 mm TB , coolant line to TB delete/ bypass, gasket match port Y runner and intake manifold. Light weight valves ( upgrade all head components )

Headers help higher rpm band

Cams are the best NA mod

Adj cam gear (-3)
I will have to look into the heat reducing tape. I am assuming you are not talking about header wrap here? Im excited about the Dezod header coming out. I hope to pick one of those up!
 

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We have an electronically control TB, at full throttle the plate should only open a 1/3 of the way. Its the magically DBW that people have asked to delete in the Go faster section.
When you say people have asked to delete, you are talking about the post? Is that because it is too sketchy to mess with the DBW?
 

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Correct me if I'm wrong but he probably is talking about deleting the electronicly controlled portion of the throttle. Lexus was trying their hand at drive by wire and they came out with a half wire half cable throttle which is stupid.
 

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When you say people have asked to delete, you are talking about the post? Is that because it is too sketchy to mess with the DBW?
I am talking about threads to delete/bypass DBW. Most people that asked about doing this were on standalones and want better throttle response. Its not sketchy to mess with but for autos it is a major part in controlling shifts i think.
 

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Discussion Starter #12
I am talking about threads to delete/bypass DBW. Most people that asked about doing this were on standalones and want better throttle response. Its not sketchy to mess with but for autos it is a major part in controlling shifts i think.
Yeah I think it is a big part of controlling shifts. I "Ported and Polished" (somewhat) an extra throttle body for my tacoma slightly and the extra amount of air coming through really messed up the RPMs at idle and the RPMS at different shift points.

I think I will just stick with tightening up the cable linkages to get rid of any slack in the wire. Is there anything you can do about pedal feel? It seems like your fighting against a good amount of pressure from a spring or something when applying throttle.
 

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Yeah theres a spring in there. Theres a thread some where on it. I couldn't find it right now but a lot of people put a spacer in it or zip ties which in effect eliminate the spring.
 

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Header wrap keeps heat in - heat tape keeps heat away
 

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Discussion Starter #15
Pulled apart the intake manifold today and there were a couple of things that excited me. I will try to attach some pictures of what I am going to describe and hopefully they work!

In image one, where the Y-shaped portion of the upper intake mates up with the upper six runners in the U shape, you can see that there is a fair amount of material that is a smaller diameter than the gasket itself. Also, where the six runners meet up individually with the lower runners, you can see the gasket marks and the smaller diameter of material that is left inside of the gasket.

In image two, the Y shaped portion of the upper manifold, you can see an incredibly large amount of material inside the gasket line. I used some arrows to point this out for anyone not understanding what I am trying to describe. That will not be nearly the amount the I would be porting, much less.

Image three is just a better picture to show you how crazy dirty the manifold gets from blow by. A clean alone would probably yield a decent throttle response gain and better flow at high RPMs.

I definitely want to do at least a slight port gasket match job and somewhat polish. I dont want to touch the very lower intake manifold just yet in fear of interupting equal head flow. I am looking into ceramic coating entire manifold as well. It would be nice to make a gasket/spacer that will sit between the head and lower manifold and not allow heat to soak the manifold as bad. Any recommended materials for this? This is a spare manifold so I am not screwed if anything goes wrong. Wanting to do some experimenting.

Hope the pictures work! Any thoughts? suggestions?
 

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Since its a spare and you have access to the right tools, definitely go for it. Love to see people trying to do "new" things.

I put new in quotations because I'm not sure it hasn't been done before.
 

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Im sure it has been done by a number of people. Like bezik777 and okcis said, its nothing new. I have not been able to find any evidence of this on the IS300 through the search and thought I'd post and document what I am going to do for anyone who is interested. As well as review any gains or noticable changes.
 
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