mx5cartalk.com

At the dyno today, Scooter is punching out good no's but the injectors are maxed out.

We flowed the blue tops and they are flowing to spec but its not enough and we are running over 14s at the top end.
Now I'm no expert and take advise from suitable persons, will going up to 305cc injectors be too much, and we do have adjustable ECU.

Or should I just go for tan or pink/red top mx5 units.

Thanks
Terry

What computer are you running? Whats its resolution (8x8 fuel table? 16x12?).

Running into the 14s is sooooooo lean youll have no pistons after 5 seconds.

305s will be fine really. Im running 550cc's (rx purple tops) on a really low resolution fuel map and its fine. But I probably am a -lot- more careful and take a -lot- more time than your tuner.

Why not just push rail pressure up for the time being?

I mean, the answer is just get the 305 supras, the 4agze 360???s or the rx7 440s or 550s. All very cheap really.

Dann

Try this
http://www.rceng.com/technical.aspx

Sailor wrote:Try this
http://www.rceng.com/technical.aspx

Thanks for that Sailor!! Just gunna be enough.

Its a shame Slammer couldn't try Scoot now, me sure him would SMILE




Terry

how much injector do you need? What cc now?

Whats your overhead with 305s?

Dann

you have PM Meester tbroooo
.... in which I lied....

I found the sources of valuable info when I was researching this way-back-when.

so you have another PM.

I have a set of Mitsi Galant VR4 injectors at home which you are welcome to play with if you wish. Typically rated at 440cc with base fuel pressure set to 38 psi.

Sounds like the OP from tbro has been answered so I'm hoping that I won't offend anyone by asking a related question to this thread instead of starting another.

I've got a bone-stock SP with a new turbo and a BOV. Whilst I was expecting the fuel consumption to be southwards of what I used to get from my stock NB8A, there are times when I'm shocked to find that I barely make it over 300kms on a full tank when I really push the car and even if I drive it like a granny, it'll be rare find to hit 400kms on a full tank.

At the same time, I've seen other people's cars where they have the same / more power and can manage 500kms when it's not pushed.

So it got me thinking:

1) Does it have to do with how the car's tuned?
2) Would it work out cheaper (and I'll probably get better performance too) if I invest in an ECU and get some tuning done by a pro so that I save more on fuel over the course of 1-2 years?

To give you an example, an mr2 engine with a big blower and some other work I build for a friend was running at 9:1 afr under boost and never leaner than 13:1.

He has since gone MS, but some quick calculations shows that he will pay for it within 5 months of the ecu upgrade, along with better driveability and HEAPS more power.

Dann

So in a round about way, what you're saying Dann is that:

- Yes, by getting a ECU and a better tune, I should be able to achieve better fuel consumption and performance (any draw backs?)
- Yes, it should work out to be cheaper in the long run, but I suspect that if we factor in the cost of getting a non-mates-rate tune, then it'll take more like a year to get the $$$ back.

FYI:

I'm getting around 13L/100km atm if I avg out granny and spirited driving modes and I drive approx. 35000kms/year. I'll need to fuel up 4550L per year at $1.69 for 98Ron = $7689.50 per year.

If I can get 10L/100kms after the tune, it'll only cost $5915.00 per year.

Which means a saving of $1774.50 per year.

How much would an ECU, installation and tuning cost in general?... (NOT mates rates)

Economy can depend on many factors including how you drive your car, tyre pressures, fuel used, and environment. (highway? City use?)

A wideband and a tunable ECU can allow you to run leaner mixtures in cruise which can help with economy but it would depend on what AFR your car is currently running and how good the tuner is. If the fuel economy on an identical car (same model and modifications) has better economy I wouldn't be looking at the ECU first. There is also the potential to make your fuel economy worse.

See if you can borrow a handheld wideband scanner and see what your car is doing now? My neighbour has a wideband you can attach to the tailpipe with a hand display unit.

Tbro I have some Supra 305's sitting in a box - pulled working out of my NA6 and low mileage since they were tested. I've upgraded to 550's.

Thanks Jerrah and Dann.

Sounds like either way, it'll be a good idea to invest in a wideband O2 sensor to be displayed at all times...

The majority of the bigger turbo se/sp's all have aftermarket ecu's.

Youll easily get an aftermarket computer and tune for 1700.

Id suggest you buy a megasquirt from braineack on MT.net, with either the alternator controller circuit, or without it, and install an na8 alternator.
Then you can load on a base map from the MS database from a car with identical or very close mods, drive it to a good tuner and probably have enough for engineering too.

Do you ever come to newcastle? Ill gladly throw my LC1 in and you can see just how good or bad it is.

Also, you will be able to get economy very similar to a standard NB8 assuming theres nothing wrong with your car.

Dann

BadBong wrote:Sounds like the OP from tbro has been answered so I'm hoping that I won't offend anyone by asking a related question to this thread instead of starting another.

I've got a bone-stock SP with a new turbo and a BOV. Whilst I was expecting the fuel consumption to be southwards of what I used to get from my stock NB8A, there are times when I'm shocked to find that I barely make it over 300kms on a full tank when I really push the car and even if I drive it like a granny, it'll be rare find to hit 400kms on a full tank.

At the same time, I've seen other people's cars where they have the same / more power and can manage 500kms when it's not pushed.

So it got me thinking:

1) Does it have to do with how the car's tuned?
2) Would it work out cheaper (and I'll probably get better performance too) if I invest in an ECU and get some tuning done by a pro so that I save more on fuel over the course of 1-2 years?

Badbong try checking the BOV as you may be getting leakage from it..
In the case of my SP it started leaking and using more fuel than my worked LS1...
I replaced the standard bov with a turbo smart bov but i couldn't get enough spring tension on it without replacing the spring.
Took it out and just put a new plastic OEM unit in and surprise surprise the fuel economy improved out of sight as well as lifting performance slighty.
Talking to other SP owners they just treat the plastic BOV as another consumable service item

cheers

t