Is a fuel pressure regulator required?

The American · Postby **The American** » Sat Aug 09, 2014 5:21 pm

I'm about to have my NB8C fitted with a Haltech and retuned. I'm going to have the tuner add a flex sensor and tune for e85 at the same time. The tuner has recommended ID1000s and a higher volume e85 compatible pump. I've got the injectors and 416lph pump on the way, but I'm wondering if this extra flow will overwhelm the stock fuel pressure regulator. The tuner has suggested that I upgrade this as well.

1) Is an afpr absolutely required?
2) Will this require removal of the existing fpr, or do they work together?
3) Any recommendations on brand/model?

davekmoore · Postby **davekmoore** » Sat Aug 09, 2014 6:14 pm

Is this a turbo?

Postby **NitroDann** » Sat Aug 09, 2014 6:27 pm

The pump and reg are a waste of money. ID1000 are almost certainly overkill also.

Dann

gslender · Postby **gslender** » Sat Aug 09, 2014 6:34 pm

Too large injectors can be a hassle to tune idle due to the lack of resolution at small opening pw - unless you absolutely have to have injectors that large, go smaller.

Sent from my iPad using Tapatalk HD

sailaholic · Postby **sailaholic** » Sat Aug 09, 2014 6:52 pm

Ids are probably one of the better injectors to go huge with due to all the published data on their behaviour.

Having said all of that unless this is a big built turbo it's way overkill.

Postby **NitroDann** » Sat Aug 09, 2014 6:54 pm

No turbo mx5 I've ever tuned needed an upgraded fuel pump. Ever.

davekmoore · Postby **davekmoore** » Sat Aug 09, 2014 7:31 pm

If you're looking to get 170+rwkw by adding a turbo these items might be worth having. Or you could buy a turnkey turbo solution with 180rwkw and sell your existing motor for similar money overall and way less pain.

The American · Postby **The American** » Sat Aug 09, 2014 8:28 pm

davekmoore wrote:Is this a turbo?

Yes, GT28 AVO kit + built engine by Mx5mania (arias pistons, Carrillo h beam rods, ported head, ARP stud kit, balanced etc.)

The American · Postby **The American** » Sat Aug 09, 2014 8:31 pm

davekmoore wrote:If you're looking to get 170+rwkw by adding a turbo these items might be worth having. Or you could buy a turnkey turbo solution with 180rwkw and sell your existing motor for similar money overall and way less pain.

The car is/was tuned to 185rwkw. From my perspective, I bought this as a turnkey solution, but I've found that the ECU is not supported (this exercise has been prompted by moving to a Haltech).

The American · Postby **The American** » Sat Aug 09, 2014 8:36 pm

NitroDann wrote:No turbo mx5 I've ever tuned needed an upgraded fuel pump. Ever.

Thanks Dan, the current pump is a Walbro 255lph unit, but a question mark on whether it is suitable for use with e85. Perhaps I should leave the pump in the box, and see if the current one is up to the job. Compared to the cost of the ECU and tuning time, the new pump seemed like a no-brainer and was recommended by the tuner.

The American · Postby **The American** » Sat Aug 09, 2014 8:41 pm

gslender wrote:Too large injectors can be a hassle to tune idle due to the lack of resolution at small opening pw - unless you absolutely have to have injectors that large, go smaller

The current injectors are 550cc, and the tuner thought they might run out of headroom for use with e85. I'd seen comments like Sailaholic's which seemed to indicate limited downside to using the larger ID1000s.

davekmoore · Postby **davekmoore** » Sat Aug 09, 2014 8:43 pm

Sounds like an interesting motor. You'll love the extra power and torque under the curve when you go E85 with that turbo unlike my weedy IHI. NitroDann is probably The Man to confirm what's needed fuel delivery wise for E85.

Mine has ID1000s and a Haltech PS1000 and it has not been easy for my tuner to get them to behave in normal driving.

sailaholic · Postby **sailaholic** » Sat Aug 09, 2014 9:14 pm

Pretty sure timk went the id750 or 1000s and had no issues at. Adaptronic play well with ID injectors though.

Seems like your tuner has a lot of issues getting your car running Dave.

Pretty unconvinced on the haltec product at this stage. Seems to be lots of people with weird issues with them and a motec is the same money.

Lokiel · Postby **Lokiel** » Sat Aug 09, 2014 9:33 pm

If you're planning on running e85, ID1000 injectors are a decent choice, otherwise are overkill and ID725s or something smaller is preferable.

gslender · Postby **gslender** » Sat Aug 09, 2014 9:36 pm

You only have to google "idle issue large injectors" and you'll find heaps of forum posts and comments from people having problems.

That doesn't mean it is impossible to get right, its just that you are close to the limits of what is possible - the physics of trying to get a device designed to deliver large amounts of fuel but also deliver very small / precise amounts isn't easy. The key elements is having the deadtimes correct, and ensuring the ecu has support for non-linear injector timing, plus ensuring you use full sequential - and having a good quality injector that has specifications for all those things (deadtimes/non-linear curves etc).

Also, not sure if timk's car is representative of a well mannered street car that idles at 850 and behaves normal at low rpms with cold start correct etc - is it?

G