Fuel for 350whp
 

I'm new to the Rx8 as a whole, but not Rx7's. After reading endless pages on the Rx8 fuel system, I am unsure if it's a safe bet to go for 350whp without doing a return style fuel system. But, I do not want to do so in this car.

So, who here is making 350whp on the returnless fuel system? What pump are you using? Did you melt the pop off valve on the stock assembly?

I am going to use blue 480cc ("claimed") injectors in all 6 locations. At the correct fuel pressure of 58psi, what are the actual flow numbers of the blue injectors? I only seem to find flow rates for the yellows.

If you are making this kind of power on a similar set up, besides a pump and injectors, what other fuel upgrades did you do, if any?

you are gonna have a hard time getting 350hp from a renny unless you want it live a very short life

I do not believe this to be true. But thank you for your concern.

Please keep this on topic. My question is referring to the fuel system. Mainly, if the returnless system can handle the abuse of this power with injectors, a proper fuel pump, and melting the pop off valve in the pump assembly.

I understand the risks of my chosen goal. I also understand what the renesis is and is not capable of. While I do not claim to be an Rx8 specialist, I do feel like somewhat of a rotary specialist.

I do not claim to know it all nor am I an expert. This is why I am asking a question. Thank you for your concerns.

Now, I am sure 6 of the "480cc" Blue injectors will handle the goal HP, but I am unsure if the direct swap dw200, dw300, or similar pumps will do the job in a factory style returnless system. I want to stay away from converting to a return style unless there is no other way to supply this amount of fuel safely.

The math to determine flow rates for rotary HP is all out there.

For example, a quick search on google: site:rx8club.com brake specific fuel consumption

Turns up this thread: https://www.rx8club.com/series-i-tec...y-math-106294/



I agree with the others though. Your RX-7 experience that you are leaning on is going to lead you to make decisions that will result in a lot of wasted money and damaged hardware. I recommend that you set aside your peripheral port 13b knowledge and start researching fresh. A lot of very very critical differences that "rx-7 rotary experts" trip on time and time again.

I understand that you are making the mistakes a "legacy" rotary owner usually do when they buy an 8. Read around and discover how many rotary experts have failed with this car because they tried to use the established tricks of the trade.

Sure your good man,
The stock system is good to 350 whp. So no upgrades are needed.


If you really want to throw the dw200 in and melt the cap and your good.

Then drive around easy for a while and the ecu will even trim out the injectors on its own. You don't even need to tune it.

Just don't run below 1/4 tank because the extra flow if the dw200 will wash out the venturi.

I think we can count the number of people who have pulled over 330 on our hands. (with proof)

OK . This is really a rather good question that I would like an answer to as well . Being someone who has pulled 350whp on a renesis (just yesterday) . I'm not happy with my current fuel pump strategy.
The Walbro255 (with melted popoff) that I have just doesn't cut it .
I even ran out of fuel in a straight line yesterday with about 1/8 tank - something that has never happened before yesterday so i suspect the walbro is on its way out - but the Walbro never really solved any of the original issues I was expecting it to either.

So was thinking :

DW300 in a S2 cradle assembly ........ anyone tried that ?

Don't put blues into P1

Better to go : yellow/blue/blue

That will give you enough for 350whp

600hp on ethanol in a piston engine maybe ....

Was advised by my engine builder who does lots of high hp FDs to go with the DW300 vs the 200.
Can you link the conversation re the venturi ?

I'm at work so I can't spend a lot of time searching, but the problem with using the larger lph fuel pump was it was too much for fuel for the cruising causing overheating and premature pump failure. That's the gist of what I got from the thread about fuel pump fixes. Run a search. It's one of the larger threads. Maybe that's not exactly what was being said but that's what I got from it

Was talking to my guy about that very issue -- he has some fuel coolers he wants me to try ................

I am mistaken, it is the DW300. I was remembering wrong. I'll go correct that first post. I am pretty sure the DW200 was close. I was on the edge of buying the 200, but got a steal on the DW300 so I went with it.

The DW200 is rated at 225LPH at 60PSI
the DW300 is 305LPH at 60PSI.

Here's the link on the upgraded 300 pump.
http://www.deatschwerks.com/news/press-releases/


I can't find the conversation about the venturi, but I think it was in the fuel pump failure modes thread.

I would strongly recommend the Aeromotive pump over Douchewerkz

Can you elaborate please?

3 years and over 25k miles on my Aeromotive 340.
I'm at 320-360rwhp depending on what boost setting I'm on.


.

Firecan is that the stock flow and pump assyembly with just an upgraded pump

you're running return setup right firecran

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been hearing of several recent short term failures (gasoline fuel) :dunno:

I was just doing name play though, but am unsure if it's a good option or not for the RX8

Correct

Yes, still stock return with a 340

I know you already answered it. But I just want to be extra clear with my question.

You are using the stock s1 fuel pump assembly with the aeromotive 340 pump and no other modifications besides injectors?

I assume you melted down the pop off valve?

What is the corrected flow for the blues at 58psi, if you do know it? I am only able to find corrected flow rates for the yellows.

I don't have the exact figures handy , but from the oem fueling scale (which is accurate) they flow 25% more than the yellows .
yellows scaled at - 476
Blues are at - 600

The reason blues in P1 is a bad idea is that they are quite a coarse spray pattern ............ not what you want for idle and cruise.

Why not buy a pair of ID725 injectors and run them in P1 with 4 yellow :dunno: