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RX-7 2nd Gen Specific (1986-92) RX-7 1986-92 Discussion including performance modifications and technical support sections.

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Old 03-15-2010, 02:13 PM   #1
sen2two
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Default Stock top mount, beefed up...

I have been wanting to do this for a few years now. And i finally dove into it. I tryed 6 different intercooler set-ups on my last FC to find out what worked best. But that had a much larger turbo. I belive with the stock turbo, the stock intercooler is best. But needs some help to be optimal. Thats when i added the water/meth, wich is great. But the design of the stock intercooler bothered me some. the entry is great, but the exit is horrible. And the TB elbow is even worse. so i did this....

(welds are kinda sloppy, i was having a hard time stablizing the arc. Found out after my TIG torch had some major problems. time to upgrade!)













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Old 03-15-2010, 02:14 PM   #2
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few more...







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Old 03-15-2010, 02:14 PM   #3
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finished product...










I did some "testing"... The intercooler made a HUGE difference. Throttle responce was VERY noticable. boost climbed much quicker. The entire powerband felt far better. I will be hitting a dyno at the end of this month to see what she makes. Im hoping for 240-250.
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93 Touring: TRADED - 91 Coupe: TRADED - 90 GTU: RHD - 88 10AE: SOLD - 87 Base: SOLD - 86 Base: SOLD - 1985 GSLSE - 85 Gsl: SOLD - 80 Gs: TRADED - 1972 Rx2
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Old 03-15-2010, 04:55 PM   #4
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Originally Posted by sen2two View Post
finished product...










I did some "testing"... The intercooler made a HUGE difference. Throttle responce was VERY noticable. boost climbed much quicker. The entire powerband felt far better. I will be hitting a dyno at the end of this month to see what she makes. Im hoping for 240-250.
Any pics of the stock setup?

If I ever get my cfd program up and running (OpenFOAM) I may be able to actually give you flow numbers/what not for your modification.
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Old 03-15-2010, 05:06 PM   #5
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not exactly sure what you mean?
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Old 03-15-2010, 07:13 PM   #6
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not exactly sure what you mean?
Before and after shots.
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Old 03-15-2010, 09:40 PM   #7
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Originally Posted by 88turboii View Post
very cool. i think most people underestimate the tmic, location isnt really that bad for under 350whp. at speed, you get plenty of air flow

Hell if you can weld like that, why not just build a completely custom IC? If you look at the stock IC, a lot of the scoop opening is wasted.. the opening is 12" tall, yet the IC is only 9".

If youve seen the ARC tmic up close, it uses all 12" of the opening (12" x 12" core i believe) and the tubes are positioned horizontal instead of vertical. end tanks are on the sides. that way the air doesnt have to take two extra 90 degree turns like the stock IC. im sure you can find a 12x12 core and fab something up? they would sell like hot cakes too
I thought about it. But i wanted to keep it stock appearing. At first i was only going to add a larger outlet on th top mount. But then i go a little carried away. I want to use all factory parts, just modified a bit for more power...

Quote:
Originally Posted by vex View Post
Before and after shots.
it was just a stock TII set-up... so any stock TII pic will do. but heres a few of the stock intercooler with some meth injection ...





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Old 03-15-2010, 06:39 PM   #8
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very cool. i think most people underestimate the tmic, location isnt really that bad for under 350whp. at speed, you get plenty of air flow

Hell if you can weld like that, why not just build a completely custom IC? If you look at the stock IC, a lot of the scoop opening is wasted.. the opening is 12" tall, yet the IC is only 9".

If youve seen the ARC tmic up close, it uses all 12" of the opening (12" x 12" core i believe) and the tubes are positioned horizontal instead of vertical. end tanks are on the sides. that way the air doesnt have to take two extra 90 degree turns like the stock IC. im sure you can find a 12x12 core and fab something up? they would sell like hot cakes too
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Old 03-16-2010, 12:59 AM   #9
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Wow... You actually changed the flow pattern a lot by doing that simple modification (just by inspection). You no longer have turbulent flow right at the entrance into the throttle body which is why you feel more power.

Having that sudden bend is better than stock as it reduces turbulence from the flow hitting a dead end wall before continuing down the hole. If you wanted even more power (though I doubt you'll need to do it) you could have the flow angle more slowly into the throttle body. This will help with the turbulence being reduced--you could also rough up the internal structure of the tubes that lead to the throttle body to disturb the laminar flow. This will help maintain airflow velocity.
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Old 03-16-2010, 10:01 PM   #10
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That's the neatest intercooler modification for the stock TMIC I've seen in a while. I'd much rather see something like this done instead of all the work needed for an FM or VMIC.
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Old 03-16-2010, 10:23 PM   #11
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Originally Posted by firzen View Post
That's the neatest intercooler modification for the stock TMIC I've seen in a while. I'd much rather see something like this done instead of all the work needed for an FM or VMIC.
Neat to see? Yes.
Practical? I don't think so.

Not many people can weld cast aluminum.
Unless the OP is going to offer this mod to others, I don't see the benefits versus a well-engineered FMIC set-up.
I believe you can get an FMIC kit with a Made-in-China IC core for like $500 off of eBay?

I doubt this contraption will outdo an FMIC kit.


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Old 03-17-2010, 02:47 AM   #12
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Well, it's not like he's welding cast "iron" now is he? Cast aluminum isn't that bad if you've got a TIG welder, just set up the wave balance to "clean" the cast out a little bit as you're welding, and use good rod.

Honestly, if you've got a bit of time and some extra aluminium laying around, this would cost like $15 tops in rod/gas/electricity bill. (not including the metal pricing)
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Old 03-17-2010, 05:03 AM   #13
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Last time I checked, a good, name-brand, entry-level TIG was going for a minimum $2,000...
Wow, wish I had that kinda equipment just sitting around.
If I had a TIG like that sitting around, there's a lot of other stuff I would be working on rather than something like this.
...but that's just me.


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Old 03-17-2010, 09:01 AM   #14
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Originally Posted by RETed View Post
Last time I checked, a good, name-brand, entry-level TIG was going for a minimum $2,000...
Wow, wish I had that kinda equipment just sitting around.
If I had a TIG like that sitting around, there's a lot of other stuff I would be working on rather than something like this.
...but that's just me.


-Ted
Miller diversion 165 can be had for 1200-1500 depending on accessories (I'm foaming at the mouth for a Dynasity 200DX though)

Though I'm with you Ted. Most people can't/don't weld cast aluminum due to unknowns in thickness, metal type, and other problems associated with cast aluminum. It can be done, but prep is a pain if the aluminum is not fantastic.

I also think a top mount is an justifiable AIT cooling method for low to medium power levels (stock-300). For more power another setup can be used to better cool the charge; v-mount, front mount, h-mount, etc, etc, etc.

Last edited by vex; 03-17-2010 at 09:05 AM..
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Old 03-17-2010, 08:16 PM   #15
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Quote:
Originally Posted by RETed View Post
Neat to see? Yes.
Practical? I don't think so.

Not many people can weld cast aluminum.
Unless the OP is going to offer this mod to others, I don't see the benefits versus a well-engineered FMIC set-up.
I believe you can get an FMIC kit with a Made-in-China IC core for like $500 off of eBay?

I doubt this contraption will outdo an FMIC kit.


-Ted
As far as welding is concerned. Welding cast isnt much different to other aluminums. Just clean it up with a file and brush it clean with a stainless steel brush.

And no i havnt had it on a dyno. But I have used three different style intercooler set-ups on the stock turbo before this one (making this number 4). And from my own personal experience (my own set-ups and others), this is much better than a front mount. Most front mount "Ebay" intercoolers are poorly designed and hurt flow more than anything. look inside one and compare it to a well designed core and you'll see what i mean. Plus the widely used 2.5" piping hurts power more than it helps. 2.5" is MUCH to large for the stock turbo. again, most people also use a super large intercooler, further hurting the set-up. Now a correctly built V-mount will be better than what i did of course, but i dont see ANY front mount being better than a modified/aftermarket top-mount for the stock turbo.

Remember, one 90* bend is equal to 5' of pipe. Now add up length of pipe and all the bends, and the big core up front wich your air has to force its way through. what does that equal? a turbo that has to work twice as hard to make give the same amount of pressure. and a motor that has to wait twice as long to recieve it...

**also, if anyone was interested in me doing this to your top mount, PM me... thatnks for the idea.




Quote:
Originally Posted by RETed View Post
Last time I checked, a good, name-brand, entry-level TIG was going for a minimum $2,000...
Wow, wish I had that kinda equipment just sitting around.
If I had a TIG like that sitting around, there's a lot of other stuff I would be working on rather than something like this.
...but that's just me.


-Ted
I bought my complete set up for 1000. and at the time, there were atleast 3-4 other equal deals on craigslist. But i did A LOT of searching to find my deal, and i was patient onm finding the right one. If you want something, the deal is out there, you just have to find it.

and just to be clear, im not trying to battle it out with you. but you seem to have a little hater-ade in a lot of your posts. here and other places. never really see anything you like besides what you do... not open to new ideas???

myself personally... im tired of the same old, "just put a TII in it", "put a front mount", "get a GT35", ect. ect. ect.... FC's need a breath of new life. Everyone has the same set-up and the same 400 hp goal. ok i'll stop... im ranting a little here.
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