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Discussion Starter · #1 ·









 

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intake porting

sometimes intake porting / polishing takes away from the atominization of the air/gas mixture.. do not know the truths behind this but have had bad experience with not getting a very performance out of ported intake chambers. I know enlarging the frst inch or so will help, but polishing the whole intake i beleive is a no, no>>> does anyone else have any comments on this....i am by no means an expert on this subject...
 

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Did you look at the pictures? He did a gasket match it looks like and then blended that into the intake an inch or so. And they are not polished they are still rough, but that doesnt matter anyway because the injector squirts directly at the valve. It looks like a good job to me!!!
 

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Yea, the polishing vs atomization thing holds light in some instances, say... throttlebody injection, or carb'd setup. But wes is right, our fuel doesn't even travel through the intake system, it is literally right there.

--BillyM

Nice job by the way. Looks very... fast.
 

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porting

yeah, i did not look that close...looks great . i plan on doing the same type of deal with mine...just posted to see what others thought on this subject..
 

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Thats the intake manifold hes polished, its the actual intake ports themselves that you want to leave a somewhat rough finish on. Looks good Will, I did the same thing with my old 82. Did you get a mop with a really look shank to get deep into the runners or just port and polish where you could reach?
 

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Discussion Starter · #7 ·
I just got to where I could reach with the dremmel. Correct I just used the gasket as a template. I started this project with the overbored TB as my inspiration...

will
 

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dyno

has anyone did a dyne before and after a job like this?? or have any technical info on to what this kind of work actually does for performance in the case of the 5mge??
 

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Discussion Starter · #9 ·
Well I'm not expection much from any indivudual mod but over all the breathing mods togather. RC intake pipe, K&N filter, removed sand trap, airbox rotated 90 deg and cold air piped in, 62mm RC bored throtle body, 62 mm bored intake plenum, Bored and matched intake plemun runners, Bored and matched lower intake runners, Ported and polished head w/ valve job.

Items I've also planed; port and polish airflow meter, cat back exhaust, hi flow cat. ceramic coating of the intake pleunm and lower intake maybe other stuff too.

I figure after all the breathing mods It should make a noticable differance
 

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throttle body

i'm curious also about the throttle body mod, and if it too is worth it?? what is the surface area of the 6 intake ports compared to that of the throttle body?? you would think that if the area of the intake ports are larger than that of the throttle body, then any thing up to that surface area would help on the throttle body..
 

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porting AFM

supra_toy said:
Items I've also planed; port and polish airflow meter, cat back exhaust, hi flow cat. ceramic coating of the intake pleunm and lower intake maybe other stuff too.

I figure after all the breathing mods It should make a noticable differance
I've done a port and polish on a couple of airflow meters. I haven't tried one in a car yet, but my gut feeling is that it should be worthwhile.
The places to work on are very obvious when you look inside the AFM. There are some restrictions on the inlet and outlet sides that can be removed. You can also knife-edge the inlet and outlet to reduce turbulent losses. I have some pics that I'll post on my website soon, but it may be hard to see what's been done in the pics.

If you calculate the cross sectional area of a wide-open AFM, it is almost exactly the same (within 1%) as the cross sectional area of a stock throttle body (TB). So, if you enlarge the TB, the AFM becomes the bottleneck. Removing the restrictions in the inlet and outlet of the AFM will increase the cross-sectional area by about 7%. Just by coincidence, the Chimp's bored TB is about 7% larger than stock!!! 8) So, I would expect a ported AFM to yield approximately the same HP increase as the Chimp's bored TB.

Here are some pics of the AFM porting in-progress. I'll be adding a write-up with these pics to my website soon.













Hope those pics help to clarify things a bit.
 

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It will be very intersting to see how our cars compare Will, our list of mods is very similar. I think the biggest hp NA 5/6mge stats so far are about to change.
 

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Discussion Starter · #13 ·
hay Dean is that 7% you mentioned from the change from 58mm to 62mm? (im to lazy to do the math right now) I figured that the runners are not so much the restriction they are roughtly 38mm round and since their is 6 of them their surface area is greater than one 62mm circle. so that leaves the TB and the AF meter the prime restrictions.

62mm is the magic number for now... :)
 

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The 7% is the change in area you get by boring out the TB.
Stock is 60 mm diameter, which gives 2827 mm2 area.
Chimpy is 62 mm dia, which gives 3019 mm2 area.

The area of the runners is huge in comparison. The TB and AFM are the big restrictions in the intake path. Port matching the runners at each gasket is always a good idea though. It will help the airflow by reducing turbulent losses.
 

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well, when someone makes a larger plenum and uses a ford 70mm tb and gets the split second to work they will be in buisness.
william
 

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only 1.5 runners are flowing at any time, ie only flows when the intake
valve is open. anyway, removal of any restriction gives some added
airflo. looks so nice i think i'm gonna buy myself a dremel tool.

if u have all those intake breathing mods, (especially with cold air on 6mg)
u mite need bigger injectors. another breathing mod is to wrap the afm
in fibreglass insulation if u have cold air. there's a little gain since aluminum afm conducts heat into airstream and reduces flo a little. i did
it and as i just said i got a small gain.
 

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Discussion Starter · #18 ·
Dean are you being a wise-ass? I would think any small gains from just wraping the afm would be unmeasurable (not to flame). Do I plan on putting some sort of thermal barrier on the afm? you bet.


By the way Dean you have way to many nice supras :drool:

will
 

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As i remember there's a feelable difference. It's simple to try and only takes 3 easily accesible screwa and a few minutes to wrap afm with 1" foil backed fibredlass and tie wraps. U must have cold air in and NOT from under driver side fender either since engine/fender wall heats incoming
air a bit. iirc, it works best on cold day.
 

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supra_toy said:
Dean are you being a wise-ass? I would think any small gains from just wraping the afm would be unmeasurable (not to flame). Do I plan on putting some sort of thermal barrier on the afm? you bet.


By the way Dean you have way to many nice supras :drool:

will
No, I'm not trying to be a wise-ass. Seriously.
But how can you "feel" such a small difference? I'd honestly only expect maybe a one HP gain from insulating the AFM. How can you feel that? :?

I vaguely remember Stan talking about his testing methods a couple of years ago on the Yahoo list. Something to do with driving in 5th gear on a flat road (or was it an incline?), and seeing how low an RPM he can be at when he hits the gas and not feel like he is "lugging" the engine.
I've tried this myself, and didn't feel any difference with my p&p'd AFM. I expected to gain a few HP, but didn't "feel" any difference.
Stan, can you help me out here buddy?

What I'm really looking for is some reliable/repeatable test method that can help me determine if a mod really makes a difference. Something other than dyno time or the quarter mile track. I've tried stopwatches for 0-60, but that isn't reliable due to launches being inconsistent. Maybe using a stopwatch to measure time to get from 30 MPH to 60 MPH in 5th gear on flat road would be better?
Maybe I should put this in a new thread and see what responses I get.
 
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