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-   -   CHEAP ASS turbo kit (https://www.rx7club.com/1st-generation-specific-1979-1985-18/cheap-ass-turbo-kit-302926/)

K-Tune 05-05-04 05:55 PM

CHEAP ASS turbo kit
 
ok...i've had an idea floating around of boosting my car just a tad.

i currently have in my posession a Garrett T3 turbo...minimal shaft play, was rebuilt at some point in its life. I sourced it from a Dodge Daytona Shelby.

i want to get away with spending as little cash as possible, so here's what i'm thinking:

no BOV, no intercooler, open(none) wastegate, radiator hose for piping, modified T2 manifold, carb hat.

hopefully with a wide open wastegate, the turbo will either make very low boost(only looking for around 4lb) or no boost at all :(

hopefully at such a low amount of boost, the nikki will be able to stand up to it. I may however have to increase the grade of my gas to 93 octane.

so any input? will a T3 turbo bolt on to a S4 or S5 mani? am i too cheap? :(

RotaryRyan 05-05-04 06:01 PM

Sounds like your just as cheap as me:D I really know nothing about turbos though. sorry

onepointone 05-05-04 06:01 PM

im interested to know about the turbo bolting up to the t2 manifold.

i have a couple comments though.

a.) if you dont run a wastegate, you will build NO boost. plus, why would you do that when turbos usually come with internal wastegates. you dont need a external unless your pushing some seriously hp, which you probably wont be.

b.) i wouldnt trust your stock nikki. i would opt to atleast buy a modded nikki for boost.

(speaking of which, anyone heard from robert from rotary shack. i e-mailed him and he wont respond to a quote on how much one would be. anyone care to share how much they spent on one?)


when you go turbo, you also have to think of the little shit. you will need to give the car more gas as more air, so theres a new fuel pump and regulator right there. then you have to worry about oil feed/drain lines. theres the lines, fittings, and if you do the oil pan, a new gasket for that.

im sure you could do it on a budget, but alot of stuff adds up quick. REAL quick

FB II 05-05-04 06:05 PM

REAL QUICK!!!!!!!!! i know from experience. i am waiting on my last two pieces in the mail for my complete setup. i have spent easily over a grand. BUT, i did get good stuff and little add ons like the HKS super sequential bov, and a nice ass boost controller, etc...

web777 05-05-04 06:18 PM

You definately need to mod the Nikki. You can't just slap a turbo on a stock carb. It needs a lot more fuel or you'll blow your motor within a mile.

ArrX7ahh 05-05-04 06:19 PM

Pretty much any t3 is going to be too small on the turbine side for a rotary. Be careful...

A KKK turbo from a porsche 930 might work, which has a t3 flange, but is largely a full t4.

onepointone 05-05-04 06:37 PM


Originally posted by ArrX7ahh
Pretty much any t3 is going to be too small on the turbine side for a rotary. Be careful...

A KKK turbo from a porsche 930 might work, which has a t3 flange, but is largely a full t4.

are you serious? i know the t3 atleast looks alot bigger than the turbo 2 turbos. how can it be too small?

cosmicbang 05-05-04 07:39 PM

Elford was T3
 

Originally posted by ArrX7ahh
Pretty much any t3 is going to be too small on the turbine side for a rotary. Be careful...

A KKK turbo from a porsche 930 might work, which has a t3 flange, but is largely a full t4.
The Elford Turbo cars used a T3 for the 12a rotary. And they had more power than the Japanese 12a turbo.

dark mephisto 05-05-04 07:48 PM

i'm interested in how you modded the t2 manifold, cuz that sounds like a good idea, and i've thinking about turboing my ride, but i might be ending up with a supercharger for cheap.

nopistons94 05-05-04 08:24 PM

i also kicked around the idea of a small turbo for my FB, running no more then 4lbs of boost really, but i want to use a small FMIC and a bov and stuff

Manntis 05-05-04 08:50 PM

if you only want 4lbs of boost, consider the $300 supercharger :)

As for the T3, the early Chrysler Daytonas had a vacuum-controlled wastegate for the turbocharger. The vacuum was controlled directly by the logic module through the use of a vacuum solenoid. This gave the ECU direct control over the amount of boost the turbo could generate. With this change, the turbo was spooled-up more smoothly to improve driveability and increase the longevity of the drivetrain. Also, a peak boost timer was added, which increased engine performance by allowing 9psi of boost for up to 10 seconds at WOT (wide-open throttle). When the 10 seconds was up, boost would return to the nominal level of 7psi. When the engine was not at WOT, the boost timer would start racking up seconds again, up to 10. Whatever amount of time was on the clock would be the maximum amount of time that the engine was allowed to run at 9psi.


K-Tune 05-05-04 09:26 PM

i have none of the parts fromt he car other than the turbo itself.

and yes, it was originally internal wastegate but i don't even have THAT.

i could plug the hole for the wastegate and run closed wastegate...but that might be way too much boost. maybe just a restrictive intake/exhaust will control the boost?

as for fuel, i'll probably use a carter fuel pump without an FPR so it will deliver 4-6 psi to the carb, hopefully causing the nikki to run over rich and compensate for the boost.

as for the supercharger, does the $300 include everything needed to run it?

FB II 05-05-04 09:31 PM

you cant let a nikki see more than 3.5 - 4psi of fuel at idle or in any normal condition not under boost. it's not setup for that.

K-Tune 05-05-04 09:42 PM

what's going to happen to it?! i asked around and i heard it was fine to run more psi into a carb that it's designed for. i know it sounds bad..but they said it was fine lol

nopistons94 05-05-04 09:45 PM


Originally posted by Manntis
if you only want 4lbs of boost, consider the $300 supercharger :)


can you expain more on this mantis ??

web777 05-05-04 10:02 PM


Originally posted by FBDrifter
i have none of the parts fromt he car other than the turbo itself.

and yes, it was originally internal wastegate but i don't even have THAT.

i could plug the hole for the wastegate and run closed wastegate...but that might be way too much boost. maybe just a restrictive intake/exhaust will control the boost?

as for fuel, i'll probably use a carter fuel pump without an FPR so it will deliver 4-6 psi to the carb, hopefully causing the nikki to run over rich and compensate for the boost.

as for the supercharger, does the $300 include everything needed to run it?

You absolutely need wastegate. Having a restrictive exh helps but you will still be boosting more than 10 psi's.

You absolutely need an FPR also. Once you reach 6 psi there will be no fuel going into your engine. The pressure from the turbo would be pushing the fuel back in to the pump.

You need an EFI pump, 4-6 psi pump won't due.

There is a lot to this than just slapping a turbo on. The most difficult thing is tuning for the carb for boost. i.e. You need to keep the air fuel ratio around 14.7:1 (14.7 parts of oxygen to 1 part of fuel) With each pound of boost, you need to raises the fuel pressure exponentially. This is an over-simpified expanation but you get the idea.

Sterling 05-05-04 10:14 PM


You need to keep the air fuel ratio around 14.7:1 (14.7 parts of oxygen to 1 part of fuel) With each pound of boost, you need to raises the fuel pressure exponentially. This is an over-simpified expanation but you get the idea.
That's not true.

Manntis 05-05-04 11:01 PM


Originally posted by nopistons94
can you expain more on this mantis ??
https://www.rx7club.com/showthread.p...5&pagenumber=1

jorx81@aol.com 05-05-04 11:19 PM

I've been thinking of using a lebaron or k car turbo(chrysler t3)

It will bolt to s4(but not s5) turbo mani right?

Thanks
Joe

web777 05-05-04 11:24 PM


Originally posted by Sterling
That's not true.
Which part?

Anyways, I didn't mean fuel pressure I meant parts per fuel.

jorx81@aol.com 05-06-04 12:02 AM

a freind said 12 would be closer to correct.

onepointone 05-06-04 06:06 AM

yea, on forced induction i think your looking for more like 12.7:1? something around there, i know 14.7 is too close to lean, and you DONT want to lean out on forced induction.

Sterling 05-06-04 07:54 AM


You need an EFI pump, 4-6 psi pump won't due.
You need a high volume pump, but it doesn't have to be an EFI pump.

You need to keep the air fuel ratio around 14.7:1...
Like has already been stated, you want a richer mixture than that if for no other reason than that it's a rotary.

...(14.7 parts of oxygen to 1 part of fuel)
It's actually parts "air" to parts fuel; Oxygen comprising only about 21% of air. (...-Or is it 18%? Can't remember) But we know what you meant. ;)
It's this one that I was really saying wasn't true:

With each pound of boost, you need to raises the fuel pressure exponentially.
You only need to raise the fuel pressure the same as you have raised the air pressure.
If your Sterling Carb is tuned to run optimally @ 3.5 psi, then you would need the regulator to deliver 3.5 psi at idle, and increase in pressure as the boost increases, simply adding the boost # to the fuel pressure #.
At 4 psi boost, the regulator needs to allow the fuel pump to push through 4 psi + the original 3.5 psi.
You'll need a total of 7.5 psi from the pump. Ensuring a high volume and pressure, you would want a slight overkill pump with a good GPH #, but it doesn't have to be a fulie pump.

web777 05-06-04 12:10 PM

Thanks for explaining better!! I have hard time explaining things like this!! Oh yeah, 12:1 is better on turbo rotaries. I was just trying to explain why we need more fuel when turbocharging.


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