TomsRX7

Need some help here: when should you upgrade the fuel pressure regulator? I've been searching for the answer on this but I'm getting conflicting info.

Here are my mods:
XS Eng T04E single turbo
Street ported engine
M2 Perf stock mount intercooler
Pettit stainless midpipe
Racing Beat muffler
PFC computer
stock fuel rail
stock 550cc primary injectors
upgraded secondaries to 1300cc (RC Engineering)
Nippondenso High-Flow fuel pump
B&M Newvolts Ignition Amp
RedHot plug wires
HKS spark plugs

Being that it is mainly a street car, I want to keep the boost around 15psi, which I'm thinking should get me about 380hp to the wheels. One person told me since I have the stock fuel rail, I will be fine without the fuel pressure regulator. I'm also leaning toward his opinion that it's much easier to tune the car with a CONSTANT fuel pressure (i.e. the stock FPR) instead of the complicating it with the rising rate.

opinions/personal experiences greatly appreciated
-Tom

fd3st04

i had a similar setup as your, and so far i have no problem with the stock fuel pressure regulator. Once i upgarded my secondary to 1600cc i will changed run an after market FPR since the rail requried to run the 1600cc injectors has a place to mount the regulator.

nocab72

You are fine with the stock rail, stock fpr and those 1300cc's. Just like fd3st04 said, if you move to 1600cc's you'll have to do a SX or aeromotive fpr then.

BTW, the stock fpr is 1:1 just like the standard SX one is, so there are no complications with the rising rate > 1:1 even when you goto the SX FPR and 1600cc's.

There are RRFPR's (> 1:1) but I don't know anyone using them in FD's since the powerfc/haltech, etc have maps which provide the ability of adding fuel in ways other than just jacking the pressure up (like most of the turbo honda guys have to)

k

TomsRX7

Nice, thanks for the answer NOCAB72. I didn't know the stock one was 1:1 too. Because I'm having my engine built right now, I haven't run the car with my single turbo yet. Do you think with my mods I will be running fine or do you think I might be close to maxing out my injectors? I plan on running 15lbs and I do NOT want to run 95% duty cycle; I'd like to stay around 80-85% duty cycle. And lastly, which brand FPR do you like better, the SX or the other brankd? Thanks.

nocab72

SX and Aeromotive seem to be nearly identical and are the only two brands I would trust in my fuel system.

According to MaxCoopers fuel calculator you should be good to 425rwhp with the 550/1300cc injector setup.

http://www.maxcooper.com/rx7/how-to/...tem/calcs.html

I have however seen stock twin cars putting down about 380rwhp and coming close to maxing their 550/1300cc setup...eh Badog?

K

BTW: You silver FD looks awesome...Silver is the *best* FD color, IMHO.

Badog

Gotta love those silver cars!

Agreed, Nocab! I have seen +90% INJ duty on 550/1300 with stock twins running 15psi and 10AFR @ 20C. That is PIGGY rich. I am sure that with more conservative fuel correction factors I would be barely at 73%, let alone 80%. But in the engine popping cold weather, I like a little buffer while I play with "other" things on the car.

I'd mimic Nocab's setup for proven performance. I will, when I go single.

TomsRX7

Thanks a lot NOCAB72. That's funny that you referred me to Max Cooper's site; he lives 5 minutes from me but I didn't want to bother him. I ask that poor guy sooo many questions. Anyhow, his fuel calculator is very nice as it takes more factors in to consideration, better than the RX7.com site. I played with it and I'm coming up with 371rwhp (.62 bsfc, 40 psi, 550cc's and 1300cc's, at 80%). I was just curious how you came up with 425rwhp.

NOCAB72 and BADOG, you both have nice cars too.

Thanks for the input guys. The first day or so I wasn't getting any replies and I was starting to think my question was beyond everones knowledge; I thought the "really smart" guys were too busy to read my post. Anyhow, thanks again.

-Tom

Badog

Tom,

You're welcome and thanks back.

The things that Max's site does not take into consideration is air temperature, humidity, and elevation. Ask Max to include at what base values he is assuming. It would have been nice to extend his tool to figure out how to change my temperature correction factors, rather than the labor intensive way I went about it.

Tony K.