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Hypothetical: Turbo N/A S5 - Cheap, low boost. How to:

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Old 04-07-09, 09:04 AM
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Arrow Hypothetical: Turbo N/A S5 - Cheap, low boost. How to:

Ok Guys,

I had this idea yesterday. I have a few too many rx7s around and was thinking. Now before you get your flamethrowers out just have a listen.

I was thinking of buying a cheap manifold from ebay or a stock manifold, a small turbo in the classifieds and running one on the NA.

Now before you guys go nuts and say the manifolds suck and you get what you pay for, and the NA drivetrain wont handle the power, I would not be looking to make more than a stock s5 turbo, or maybe slightly more, maybe 225 or so. I would like just a little extra scoot since I have the car to do it on.

I am thinking of the bare minimum I would need. I know this **** has probably been covered a few times and I should just search, but I am trying to be a little more specific as to the most cost effective way to do it.

With my goals being minimal and wanting to do everything pretty much bolt on what would I need?

Here is what I am thinking:

A stock s5 manifold and turbo. I would port and mod the manifold/wastegate slightly?
Block off the fifth/sixth ports?
Block off emissions
Get an apex'i n1 exhaust cheap from my friend dan?
Now I should have enough in the stock fuel system to handle the power.
A nicer clutch should also do the job.
Run an oil line to the turbo
I'll have to find a way to run a cheap front mount intercooler.
I need a cheap option for fuel management, modding or swapping to a t2 computer.

Guys my power goals are minimal and I have access to the stuff I need, so let me know. Thanks-
Old 04-07-09, 09:12 AM
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Engine, Not Motor

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If you intend to run the stock TII exhaust manifold, you either need to make a spacer to clear the NA lower intake, or move to the TII intake manifolds.

Your basic plan seems fine. There is a good amount of fab necessary to use an exhaust spacer since it moves the turbo from the stock location.
Old 04-07-09, 09:18 AM
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if you used a spacer for T2 exhaust manifold, you would need to make your own oil and coolant lines. All those fittings get expensive, it would be a couple hundred dollars.

good luck finding a USDM s5 T2 computer on the cheap (N370?)
Old 04-07-09, 09:54 AM
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I did some more reading. See I am not looking to go nuts like Aarons setup. Just some modest power gains. The labor is no problem at all. I do it all myself and more stuff to keep me away from the old lady the better.

So I would need a spacer for the manifold, I would need to run the oil lines, but I didn't really think the oil lines would be that expensive. I can deal with a 100 bucks, but anything over that is sort of pointless.

I want to bargain hunt, build it and document it.

So I will need s5 turbo manifold/turbo-
Spacer
Oil Cooler lines
PFC for the fuel?
I will need some other small things like a boost guage, stuff like that. Bigger injectors. I mean I know this has been covered a few times and I was reading other threads, im not a newb either.

I didnt get much sleep either last night, so that probably lends to my stupid question factor.
Old 04-07-09, 10:00 AM
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I love the lamp!
Old 04-07-09, 10:25 AM
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Ok is the spacer something I can buy or something I would have to make?

I would cut the actuator off and mount it to the engine bay and use the bicycle cable to keep it working so I wouldnt have to notch the frame.

I would also tap the oil from the pressure sender as it leaks and needs to be replaced anyways.

I would also tap a return, though weak, it would work with an AN fitting.
Old 04-07-09, 10:37 AM
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Make. And if you use a S5 turbo, you'll hit your frame rail when you space it.

You'll need to either use a S4 turbo/spacer, come up with a more 'creative' spacer that allows the S5 to fit without hitting the frame rails, or swap to the TII LIM/UIM.

Pretty much the bare minimum would be some kind of ECU, fuel pump, at LEAST 550 injectors all around, clutch, oil feed/returns, and some hackjob intercooler. Everything else is straightforward.
Old 04-07-09, 10:53 AM
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Rotary $ > AMG $

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Why not-

http://www.rx8club.com/showthread.php?t=124336

http://www.rx8club.com/showthread.php?t=97855
Old 04-07-09, 02:12 PM
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Why block off the aux. ports?

They would allow for more torque down low, and then just open them when the turbo starts to spool. Can be done electronically with Summit racing RPM switch. Cheap.

You don't need all that much opened at lower RPM when the turbo isn't spooled at all.
Old 04-07-09, 02:20 PM
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i read that. I would leave the aux ports. My mistake.

Pretty straight forward then. Or I could simply use an s4 turbo manifold with s4 turbo. Probably cheaper to find on the forums. I would also need to fab a downpipe with an 02 sensor bung. Hmm.

Now it is just a matter of pricing it all out. Cool. Thanks guys-
Old 04-07-09, 02:25 PM
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Originally Posted by Rx7TyreBurna
Why block off the aux. ports?

They would allow for more torque down low, and then just open them when the turbo starts to spool. Can be done electronically with Summit racing RPM switch. Cheap.

You don't need all that much opened at lower RPM when the turbo isn't spooled at all.
You typically take the actuators out because they make mounting the turbo even MORE of a nightmare. You either can replace it with servos/relocate them, or move the turbo. And their benefit wasn't worth the effort in my testing.
Old 04-07-09, 02:37 PM
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Ive been giving something like this serious consideration as well. Aside from the mounting issues to work out, would the N/a computer freak out when the map read boost? If so, couldn't you just put a check valve in that line and use a rising rate fuel pressure regulator to add the extra fuel you would need under boost? Would prolly be a good idea to use some kind of piggyback management as well, emanage blue is super cheap and should get the job done. If you had the cash you could even get the greddy pressure sensor and not let your factory ecu see the boost at all.
Old 04-07-09, 02:40 PM
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Originally Posted by SonicRaT
You typically take the actuators out because they make mounting the turbo even MORE of a nightmare. You either can replace it with servos/relocate them, or move the turbo. And their benefit wasn't worth the effort in my testing.
Good point. Forgot about the huge actuators. I agree, they will definently get in the way.
Old 04-07-09, 02:41 PM
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Originally Posted by SGPguy
Ive been giving something like this serious consideration as well. Aside from the mounting issues to work out, would the N/a computer freak out when the map read boost? If so, couldn't you just put a check valve in that line and use a rising rate fuel pressure regulator to add the extra fuel you would need under boost? Would prolly be a good idea to use some kind of piggyback management as well, emanage blue is super cheap and should get the job done. If you had the cash you could even get the greddy pressure sensor and not let your factory ecu see the boost at all.
It doesn't 'freak' out, or do much of anything really. It just never pulls timing back, which can get ugly depending upon the available fuel/EGT/IAT/etc. I was running 10psi on a S4 N/A ecu with just an S-AFC 4x550's and a FD fuel pump. I had a semi-decent FMIC and it was running about 11:1 though.
Old 04-07-09, 03:02 PM
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Originally Posted by SonicRaT
It doesn't 'freak' out, or do much of anything really. It just never pulls timing back, which can get ugly depending upon the available fuel/EGT/IAT/etc. I was running 10psi on a S4 N/A ecu with just an S-AFC 4x550's and a FD fuel pump. I had a semi-decent FMIC and it was running about 11:1 though.
w/a stock turbo? That sounds pretty nice. What did you do ( if anything ) for timing control?
Old 04-08-09, 12:50 AM
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Yeah I don't really see how this is different from Aaron's setup. Unless you're referring to his current setup, his original project consisted of all the parts you are mentioning. The oil and coolant lines are not going to cost you $200, not even half. You will need a 3 foot oil line 1/8" NPTX2 with a swivel fitting on one end that you can get from a hydraulic store for about $40. Remove the stock supply line and tap for 1/8". For the drain and coolant lines you can cut the stock lines off and run hoses/clamps. All stock coolant lines are run this way. The oil drain has no pressure whatsoever but is subjected to manifold heat so buy a braided hose online for about $20 and use clamps.

BTW I have a spacer for sale for $30+shipping.
Old 04-08-09, 04:44 AM
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why not just get a cheap J-Spec motor for about 800 on ebay if you are going to do it cheap and ghetto (run the na electrical?)

i would probably run T2 manifolds at the minimum for the na motor... spacers just seem... kinda ghetto to me...

and it is still the "wrong" way of doing it....

and you need to find a way to run the coolant line and oil drain.... oil feed - just run a T at the oil press sender...

just do a real swap.... or just run true duals... they just look cool and sound cool... or paint every pulley you see and every part to make it look faster like all the NA guys....
Old 04-08-09, 06:54 AM
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those jspecs motors are usually a gamble and have to be rebuilt. the mans on a budget
Old 04-08-09, 07:04 AM
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He can do it cheaply and keep working it up better, +1 for the 6port turbo (My plans once got a m/t)

-1 on the spacer, and japan2la has the thing you'll need so you dont need the spacer right?
Old 04-08-09, 10:19 AM
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Yeah I am trying to do it as cheap as possible, not necessarily because I am broke, but mostly for the sake of doing it and doing a write up of my own on it, and how low I can go. My expectations are not high.

I am definitely not looking for ALOT of power or something I can abuse.

You guys remember that story of guy who traded a paperclip for other stuff until he eventually got a house?

I feel like in a way I am trying something similar, just to build something decent myself, as cheap as possible, but decent.

An example. For my fc that I am ls1 swapping and widebodying I would have spent massive amounts of money if I bought everything at price

I have an ls1 with 28k, mounting kit, widebody kit, carbon fiber adjustable racing seats, 2 18x 9.5 fno1rc's with brand new tires, just need the other two.

For all of the above I paid $2675 for. Ur lucky to get even an LS1 for that much alone, more or less the other ****.

So with that being said, I'm looking more to do a "guys, hey look what I managed to do type deal"

The plumbing sucks thought, but if it HAS to be done then it has to be done.

And I have no interest in buying a jspec motor and not knowing what you get, and then having to rebuild ****.

If I was going to do that then I would do it on this vert I am doing an LS1 swap into.

Lets try to imagine a cheapest total cost here with low expectations.

S-afc= $100 ?
Oil lines= $200
s5 turbo and manifold= $150
Ghettocooler= $125
Injectors=$100

So around 7-800 bucks on the cheapest side of things? And I mean after doing some serious bargain hunting, not just what you would normally pay. Plus you have to pay for all of this little nickle and dime stuff over time, but lets not account for that.
Old 04-08-09, 12:10 PM
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S5 turbo and manifold $200-350 for a decently good one.
Oil lines $100

Other than they you have everything right.
Old 04-08-09, 12:13 PM
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I don't see a mention of a fuel pump, did you already upgrade that?
Old 04-08-09, 01:00 PM
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Is the stock pump near max? I know for low boost, the RX runs normally rich. Maybe just a little extra open times on the injectors won't effect the pump too much. But, I don't have any hard evidence. I have a 225 regulated by an external fpr.
Old 04-08-09, 03:04 PM
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Im not really sure. That is why I am throwing this out there. I mean I wont be running way too much boost or fuel that the stock NA pump couldnt handle but in all honesty I really dont know. I am sure I can scrounge another used cheap pump for not too much.
Old 04-08-09, 03:08 PM
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I'm pretty sure I have read about people using a supra pump?


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