GoodfellaFD3S

iTrader: (213)

This is assuming that you're not all running 1600/1680s.

I'm thinking about making the swap soon.....I've had no issues with my RC Eng. 1300s, but have heard rumors of horror stories and sure as **** don't want any fuel injector issues when I'm tuning for 17psi on my BNR stage 2s.

Comments, opinions, ridicule all welcome .

SPEED_NYC

iTrader: (3)

a friend of mine in Tampa had a real nightmare dealing with RC for a set of 1300's. he had to send them back 3 times before they got it right. for some reason they wouldn't pulse properly, they just stayed open.

his forum name is JBUER or something like that, i'll tell him to post his experience here

nocab72

We've had problems with them sticking open and dumping fuel like crazy... If I were you I'd just go 1600 w/a new rail and FPR.

Of course now saying that, I just got a set of 550's that I had RC bore out to 850's for a nice fit in my primaries.

k

singleturbofd

i deal with RC all the time with injectors, i have no issue at all with all the 1300cc theybored it out for myself and my customers.'

Marcel Burkett

None at all

artguy

my 1300s drip fuel when the car is shut off and they have less than 3k on them....at least this is my judgement on why my oil smells like friggen race gas. I change my oil every 3-500 miles right now.

for the power you are shooting for the 1300s will be topped out anyhow...

you got no choice but to go with the 1600s and the rail.

otherwise you are grounded to about 400 or so Id guess...and god knows you are not one to be grounded.

might as well do it right the first time.


jason

TomsRX7

ARTGUY,
I recently got the XS Engineering T04E kit and I'm expecting to get about 380rwhp at 14-15psi. I have the Nippondenso high flow pump and RX Eng 1300cc sencondaries, stock primaries (as well as a slew of other mods that can be reviewed if you click on my website link below). I've gotten mixed opinions on whether my fuel mods are sufficient- some say yes, others say no. And different "fuel calculators" have also given me different answers. Can I get your opinon on this? Thanks buddy.

PS- you live in Laguna? I work in Newport.

-Tom

Mr rx-7 tt

iTrader: (5)

Topped out at 380 rwhp..? I have seen 400 rwhp on STOCK injectors..(T-78) Call Peter Farrell or call Jeff at Rotary power..they also have seen these numbers on the stock injectors..as a matter of fact Peter Farrell used to dyno 485/500 rwhp with stock (2) 550's and (2) 1200's..
Some of you guys offer advise but don't know what you are talking about.

Mr rx-7 tt

iTrader: (5)

Rich,
You have more injector then you will ever need for those BNR's. Before you waste your money on those (turbos) do a forum search...

nocab72

Personally I would prefer to run with a 20% cushion, than on the ragged edge (like that to be done in your examples above) and my advise typically follows that as well.

There are LOTS of ways to do things cheaper, I prefer the ways that cost a little more, but keep my car on the road.

k

vosko

iTrader: (4)

i would rather have more fuel than just barely enough.... i am running 550's bored out to 750's no problems yet

Brad

I think they do know what they are talking about. You on the other hand...

Let's take a look at a little dyno sheet I have. This is a large streetported T04S running 108 octane.

461 rwhp T04S

That was with 850cc in the primary and 1600cc RP rail on the secondary. Oh, and a BIG *** bosche pump and SX RRFPR.

Now let's take a look at the AFR and fuel pressure chart from that run...

AFR Chart

The primaries were at about 93% duty, and the secondaries were at 88%. Base fuel pressure was at 38.5 psi. You can see fuel pressure dropping off at about 19 psi.

There wasn't enough fuel to safely support 461 rwhp.

Final tune was a safe 419 rwhp. Injector duty was still pretty high though, but I can't recall exactly what, it was too high for my liking.

Also, go to http://www.maxcooper.com/rx7/how-to/...tem/calcs.html I think this is a fairly good calculator and gives a good estimate of what your fuel system can support. I put in a BSFC of .60, fuel pressure of 40 psi, 550cc x 1200cc and injector duty of 85% (He says this is the controllable limit).

This will support 383 rwhp, according to the calculator. Who doesn't know what they are talking about (don't get mad ) ?

I know PFS is a fairly reputable shop (errr, to some anyway)...but I won't believe for ONE SECOND that ANYONE made 485-500 rwhp on 550cc X 1200cc. Show me the chart and I will shove my foot in my mouth, on camera so all of you can see

Mr rx-7 tt

iTrader: (5)

Nocab 72,
I agree with you 100 per cent. I wouldn't suggest running 400 rwhp on stock injectors but I have seen it done. I also agree that it is better to be safe than sorry. My point was twins (Bnr) will have more than enough injector with 550s and 1300's.

Mr rx-7 tt

iTrader: (5)

I know exactly what I am talking about. I have been doing this for 20 years. I hear the same info that the stock injectors can't handle 360/370 rwhp yet I have been setting cars up this way and have never had a failure. The caluculator on Max's site says the stock injectors are good for only 305 rwhp at 85 percent duty..

The calculators are a decent base line and Max points that out. (Some of us use calculators and some of us have experience.)
If you want to believe that you will run out of fuel at 460 rwhp with 2X850's and 2x1600's then go ahead.
But don't tell that to everybody else who has seen well over 500 rwhp with that set up. I advise you call some reputable tuner shops that have experience with tuning RX-7's.


BTW: You need to look at the knowledge base, education and record of Peter Farrell....He, Ray and Russell know what they are doing.

TYSON

Gotboostd7, where are the units for fuel pressure on that chart? The scale for fuel pressure must be very large, because as boost was rising, the fuel pressure line was barely moving. With a rising rate fuel pressure regulator wouldn't the slope be much steeper? Like if you had it set at 3:1, the fuel pressure would rise three times faster than the boost. Also, if your fuel pressure is dropping under high boost and high duty cycles, doesn't that mean you don't have a strong enough fuel pump to provide high pressure when the injectors are open?

I'm afraid I don't follow your logic, especially when I know others with the same injectors as you WITHOUT a rising rate regulator able to put out 540 rwhp.

Brad

The regulator was set to 1:1.

The units for fuel pressure aren't shown because the program used only allows two units to be displayed, and they chose boost and AFR. And yes, the scale is not the same as the boost line. Imagine the beginning of the fuel pressure curve as base pressure, and the peak is at peak boost.

Now that I look at it more closely again, I remember we didn't loose fuel pressure. We had trouble controlling boost. I'm pretty sure this run was done off the wastegate spring. You can see that the boost pressure decrease is parallel to the fuel pressure decrease. Sorry for the confusion.

At any rate. I do know the injector duty was high. Above 85% for primary and secondary.

You can call Ralph at Excessive if you want. He tuned the damn car. He can tell you the fuel wasn't there to support 460 rwhp. These were brand new 1600cc and freshly cleaned and flow matched 850cc injectors.

You said you've seen 540 rwhp with the same injector setup as the graph I provided. There is a big difference between 850cc x 1600cc and 550cc x1200cc. Again, Max's calculator says BSFC of .60, 40 psi base pressure, and 850cc x 1600cc will support 530+ rwhp @ 85% duty. I'm not challenging your claim at all.

What I want to see is a graph of 485-500 rwhp on a 550cc x 1200cc setup, as someone claimed.

Brad

Well, I apologize for coming off a little harsh. I know Farrell and what not have been doing this longer than I've been alive.

But I KNOW what I saw!! Yes, I was standing right next to the car with 850cc x 1600cc when it put down 461 rwhp! Yes, I SAW the datalog! There is no "believing"...the datalog isnt the freaking bible! It doesn't require faith. Numbers don't lie. 1=1

Okay, okay, okay. Let me back up and re-state my thoughts. What ever power claims you have for any given injector setup MAY be possible. What I am talking about is STREETABLE setups. I am talking about what is safe. What people actually run on the road.

If you can look me straight in the face and say someone is making 485-500 rwhp on 550ccx1200cc at a SAFE AFR, and SAFE injector duty, then I will never post on this board again. Ever.

setzep

You know Brad... he never posted what fuel pressure he was running. Who knows maybe he was running 100psi.

Get ready to shove your foot in your mouth on camera for every body to see

Mr rx-7 tt

iTrader: (5)

I agree with you that safe is ALWAYS better and I don't think you came off as "harsh"..

Brad

You are right Cam...but, how many street driven (again, that's what I'm talking about here, and assumed that's what everyone else was talking about) RX-7's have a fuel system has enough flow @ 100 psi to make 500 rwhp?

setzep

I was just stirring the pot I know, not many fuel injectors like 100psi let alone fuel pumps.

TomsRX7

As for fuel and the FD, I know I don't have quite the experience as some of the other guys in this thread, but here is my opinion:

for Peter Farrel and some of the other guys who are supposedly squeezing 500hp out of the stock injectors: you know they are running them at 100% duty cycle. At that level, you lose the controlability of the injector. Also, I'm sure they raised the fuel pressure a lot, which is not good for the injectors. So is it possible? probably. But is it a reliable setup, especially for the street? No.

I would rather run at 70% duty cycle and a lower pressure. Anything mechanical always runs better in it's "sweet zone".

And one last important think I want to point out: PFS advertises a single turbo kit on their site good for 500hp at 15psi. You'll notice a pretty little red star next to it. And what that star means is flywheel horsepower, not wheel HP. That right there makes me lose respect for them. The standard everyone qoutes is RWHP while they qoute flywheel??? And that's probably the reason they CLAIM to have gotten 500hp with stock injectors. Translate that to wheel HP and now you're down to 425HP. So with the fuel pressure through the roof and running 100% duty cyle, MAYBE they did. Damn those PFS guys are great marketers!!!

Just my $.02

-Tom

GoodfellaFD3S

iTrader: (213)

Do you know something negative about the BNRs that I haven't heard about?

Rich