1)Denso or Walbro fuel pump
2)550/1300 super simple but good up to 400whp

 

wouldnt 1300s be a little much for 300whp? any idea what duty cycle they would run?

 

I have a denso pump with 550 / 1300 making ~310 with stock twins and streetport at 10psi

I was playing with my boost controller the other day and peaked about 75% at 12psi 7500 rpm... running a litter richer than it probably should be. Car came with 4x850's but I didn't like the idle richness or driveability...

going larger on the secondaries shouldn't cause you any real problems and gives you room to play in the future...

 

ok awesome... thanks for the info

 

I've seen people push their injectors far beyond what you're reporting. Makes me wonder how rich your tune is.

 

I guess he is probably close to 11:1 I was at 10.5:1 at just under 12psi because I am not tuned there and I was at 75% but I have about 32% more injector flow so his injectors would have been somewhere in the 95+% at the same place just ballparking with rough math...

Twin you don't have a wideband do you?

 

nah i dont but i can check out the dyno graph and look at the a/f ratios they tuned to... whats ideal a/f at wot for these rotaries?

 

Depends on your goals and who you talk to. I will give a general run down but I am sure there are people that will disagree.

Basically you have two things to worry about:
1. Carbon Build up
2. Detonation

You want to go rich enough to prevent detonation but not too rich to avoid excessive carbon build up.

I have heard of people running in the 9 ~10 AFR area but this is waay too rich I believe. Without AI and other detonation control I would stay near 11:1.

You will make more power if you can lean it out a bit. I do't know where LBT is on a rotary but probably somewhere in the 12:1 ~ 13:1 area but the risk iof grenading the engine increases significantly and I would never run here withour A/I and race fuel or something else to protect against detonation. To give you a general rule of thimb idea every A/F richer gives you about an equivalent 5 octane increase in knock prevention, I don't know how true that holds once you start getting far away from stoic however?

Basically the simple anser and what I do in my car is I target 11:1 above 5psi. Above 10psi I hav it a little richer right now becuase I haven't tuned there and just want to be safe in case I get boost spikes or something, but I never deliberatly go below 11:1...

Some people have told me this is too rich and the spark need to be tuned better, but bascially I don't believe them. Spark doesn't matter if you get preignition detonation so I stay at 11:1 and sleep well at night .

jsut a disclaimer every engine and every tuner if different so do what you will to your own car, I take no responsibility

 

according to the dyno graph the afr stay around 11.5:1 then slowly taper to 10:1 by 6500rpm

 

http://www.turblown.net/store/index.php?productID=262

http://www.turblown.net/store/index.php?productID=63

( Will need two of the above fuel injectors, top feed fuel rail, fittings hose, and aeromotive a1000-6 fuel pressure regulator, and of course re-tune).

 

Those are the stock sizes. I'm somewhat skeptical of the torque number though. I wanna say I made around 300 at HP.

Assuming the engine is healthy, 340 is very possible with $3k in parts. Loose the emissions, say with a deserter, water injection and an aggressive tune you might do it.

If 340 isn't enough, you aren't going to be happy with 360 either, just saying. I've been where you are, just finished going single this week. Going to around 340 is a huge leap. Also that's wear weak parts start to fail. Doing everything right with all the gotcha's can send costs through the roof too.

Get use to it, while you research your next step thoroughly.

 

i think im just gonna upgrade the fuel pump and get 1300cc secondaries and a mid pipe then go get it tuned at kdr performance and call it a day until i have money to rebuild the motor and get a port...

just another quick question... whats the tube coming from the cat? is that for egr or something? what are you guys doing with that when running without a cat?

 

It's from the air pump. When i went to a strait pipe i left mine just sitting there, unattached to anything. Its impossible to remove because it snakes up and over the tranny. I finally blocked off emmisions and that tube is still there......it will be until i drop my tranny

 

haha ok sounds good

 

and how do YOU know that officer Jim? Would this possibly involve a certain FD owner with a car mothballed in Florida?

go to an exhaust shop, have them cut and clamp the end that is metal, then weld it shut.

 

Def upgrade fuel and ignition. And if still not satisfied, go single turbo and have fun.

 

No need at all to do the ignition with his setup unless something is wrong.

 

Fuel, Ignition, AI, Tune.

Then next step is pricey $5k+

IMO

 

Yes. those are stock. i was running 550/and what i believe was 1300. i was at around 9x% injector duty.. once i swapped to 1600 secondaries i was able to put it to 360

Mods id suggest...


-just getting new secondaries. 1600cc secondary injectors will be more then enough to reach your goals.
-Denso "supra" fuel pump
-FPR if you want to splurge
-add the fuel pump relay
-delete the fuel pump resistor (the coil pack looking thing UNDER the brake booster. just cut the coil out and loop the wires

dont listen to everyone about changing ignition. you'll be fine. if its working fine then DONT change it. IFFF there is a problem, switch to the T2 leading coil. cheapest solution and the t2 coils are hella better than the fd's

 

take it back to KDR and ask for advise. The forum will give you many opinions but only ur tuner can tell you how he feels your car will do with his tune..

 

First need to understand what the AFR's are at full load and the duty cycle you are seeing. If your AFR's are below 10.5 you may have a little room to add air if the system can add air. In order to ascertain if the system can add air need to look at the waste gate duty cycle. Regardless, with the setup you have I don't think you can get an order of magnitude change in output. Might also want to take a look at the knock frequency at full load; this is also an indication of how much margin you may have.

I would tend to stay on the fuel rich and low knock areas to preserve the engine; especially with operating in the upper ranges of the equipment you have. You are at a point with this setup that you need to throw a lot of money at it to get to the next level and stay reliable.

You do need to consider a stronger ignition at boost levels above 16 PSI. I have first hand experience and my combination is very similar to yours. This thread will take you through it: https://www.rx7club.com/power-fc-forum-47/high-load-stumble-909607/

 

You've got some room in your tune. 10:1 is rich, even for a turbo rotary.

 

awesome thanks for all the info guys

 

kdr is over 5 hours from me but ill make the drive once i upgrade the fuel system... looking at the receipt from the previous owner when the car dynoed at 304whp it only says a $75 charge... so that was just for the 3 dyno runs and not a tune and i dont see any receipts for a tune... it made lower power at 10psi and then they made a pass at 12psi and it made 304whp... so looks like this thing is running without a tune which sketches me out a bit... the af ratio graph does look pretty eratic i would figure the tuner should be able to get the af ratios pretty consistent across the entire rpm range... any idea how much kdr usually charges for a tune?

 

KDR aka Speed1 charges $300 for a dyno tune starting sept 1st. I'm taking my rx to them.