eprom chip

[1SlowCA18DET]

can someone make me a eprom chip that will eliminate boost cut that is all i need, also if i do this will i still be able to use my safc?

[Not_a_sr]

no most people who do eproms will not remove the factory fuel cut, it is there for a reason, and if you are hitting it then you need to change up your setup...

im seein 258-260some HP at the wheels and i have yet hit fuel cut. my A/Fs are still pretty safe... also if you get an eprom really not much use for a AFC they are not a good choice for tuning when there is acess to better methods for just as much if not less.

[1SlowCA18DET]

so what your saying im not suppose to run more than 15 psi even if everytihgn else have been upgraded?

[PulsarDet]

The fuel cut is present when the maf is not able to read the cfm, since the stock ca18det maf is good for about 260hp ,if the car make 300 then the fuel cut will act !

[sdtouge]

i thought the stock maf is good for like 230 ish, sohc is better, but thats besides the point.

yea fuel cut is there for a reason. its like completly remving the rev limiter, not a good idea.

[1SlowCA18DET]

o ok i didnt know that it gets it reading from the maf which causes fuel cut, i always thought it was able to read boost and at 15 psi the fuel cut would accour. im such a newb. looks like i need a z32 maf or a rb25det

[Not_a_sr]

i think it reads maf voltage and maybe injector duty cycle, but dont quote me on that.

[sideways danny]

Jez Horshams chips remove fuel cut, infact all the chips on the UK market do. have a look on http://www.h-dev.co.uk

[pulsar gtr]

The stock ca18det will max out at 190whp. If you are running 15psi on the stock turbo you are not only exceeding the maf limits but you are also maximing out your fuel injectors that if they are still stock 370cc.

If you still want o remove the boost cut off, I can do it for you, just shoot me an email to [email protected]

keep the boost less than 14psi as you will be maximing out the turbo limits, T25 Ca will max out at 15-16psi.

Good luck,RafiPULSAR GTR

[sideways danny]

what???? 370s won't max out anywhere near that early. I've seen cars with standard maf and injectors run t28 at 15psi, this gets about 270bhp at the flywheel.

have a look at the site I linked to, those chips hve been used pretty reliably for several years

[pulsar gtr]

A CA MAF will not run run 15psi on a t28unless you are using an safcII or similar devices to fool the ecu( the 15psi T28 turbo on stock injectors and maf are very hard to believe man, I am not doubting you but from experience I find it impossible), and the stock injectors will max out at 16psi on the stock turbo, I ran out at 16psi on my stock injectors and turbo using jwt ecu, mind you that jwt ecus run a bit richer than normal ecus.

PULSAR GTRRafi

[1SlowCA18DET]

where does the sr turbo max out?

how did you get 16psi to hold on your stock turbo?

[float_6969]

A 370cc Injector at 100% duty cycle is only good for about 260hp. I don't see the stock CA MAFS pushing that kinda air through it either, but I don't have a whole lot of experience with it.

Maybe the UKDM MAFS have a higher flow rate?

[tineira]

Motec tech guys say that you need about 5cc of fuel for each HP so 370*4/5=296HP (at the flywheel). This is with standard fuel pressure.

Also the CA AFM (JDM is the same as UKDM) is supposed to max out at about 190HP at the wheels.

[Not_a_sr]

its proven that you can get 260hp at the wheels on stock inj and a KA maf.

i only seem to be running a little too lean around 3-4K while building boost.. i may have to richen up the maps there and/or bump the fuelpressure up a little.

[sideways danny]

technically the standard AFM runs out of definition around 190, however that's not what maxes out the injectors. A map can be written to take into account the TPS signal beyond the AFM range, a lot of OMEX mappers use TPS only.

if you have a look at SXOC you'll see Kev ran 293bhp at the fly on 370s std AFM and fuel pressure raised by 2psi. He runs a very good FMIC and an s14 t28 turbo at 15psi. this was using a horsham stage 2 chip

[float_6969]

I don't understand the appeal of maxing out your stock equipment. I mean, as has been shown, you CAN get 290hp out of the stock injectors, but you've GOT to be running at or near 100% duty cycle. Everything I've ever read/been taught was that you should never exceed 85-90%. The same thing basically applies to the MAFS. Why would you WANT to max it out? What is the appeal?

You should tune your car so that your setup and goals never exceed 90% of the capabilities of you equipment, not just electronics.

[pulsar gtr]

That dude isn't playing safe, he is maxing out every thing, basically he is following this example, take a completely stock ca18det slapping a huge turbo and injectors and getting 600hp out of it, ya, it might work for a couple of runs, but guaranteed it will blow as it isn't built for this kind of hp to begin with.I have a small saying that says "if you want to play, you gotta pay" don't cheapen out on stuff that is critical to your engine life because you decided to take every thing to the max of their limits. Mechanical components as well electronics don't like to be run at max limits, bad things tend to happen.

But I still find it impossible to run 16 psi on T28 on stock injectors, why in hell did Nissan went to 440cc injectors when they used the T28 turbo on the Sr or the RB, Nissan have some serious engineers that none of us get close to their knowledge. and expertise. My two cents of opinion.

PULSAR GTRRafi

[Not_a_sr]

dont worry i have 550s and a z32 maf goin on the car.

we actually put them on last night but somthing in the program we wrote was completely off cause it wouldnt run for ****, acted like it had a bad maf. 10to1 AF at idle and just cut out with any pedal. my computer had been fried before so we threw all the stock stuff back in. It ran on the stock computer and if was good to go, so we put in the chipped ecu and ran it with program for stock inj,stock maf, ran good... so we dont know what we did wrong. mabe injector adjustments are off or somthing, ill prob try the z32 maf with stock injectors just to try and narrow it down.

[pulsar gtr]

Hi Not_a_sr,

What was your K value for the 550cc that you used, also did you illiminate the first 12 values for vqmap when you used the Z32 maf.

Your K value should be around 7A hex.Did you have the z32 maf hooked correctly?

Good luck,

PULSAR GTRRafi

[datsunboy]

why anyone would want to run the CA MAF with any decent power is beyond me too.

besides any electric reasons, look at the tiny hole of the CA18 maf!!!its worth going to a bigger sized maf like the RB20 or better just for the airflow restrictions I reckon.

[c-rad]

All you need to know for fuel injector sizing....

http://www.rceng.com/technical.htm

And I would NEVER run more than 90% duty cycle. I'm all set with a failing injector and dead piston. Especially on some old-*** 370s that have been in there forever.

[float_6969]

Alright smarty pants, what is the Brake Specific Fuel Consumption for our motor?

[pulsar gtr]

I was checking the link above and it mentions 0.60-0.65 for turbo engines, so I plugged in some values and the it came up with some funny numbers.!!!!!

PULSAR GTR

[c-rad]

I was checking the link above and it mentions 0.60-0.65 for turbo engines, so I plugged in some values and the it came up with some funny numbers.!!!!!

PULSAR GTR

Did you remember to change the pressure at the rail? I just used a base pressure of 37psi and added 15psi (max pressure to run on an SRT25) and put 53psi. My numbers came pretty spot on....

300BHP4 injectors0.60 BSFC0.85 (85% duty cycle)53psi

I got the minimum injector as 505cc which looks to be spot on for that duty cycle. Bump it up to 95% duty cycle and you get 451cc which again, is spot on. 450s max out at around 270whp.

[Not_a_sr]

Hi Not_a_sr,

What was your K value for the 550cc that you used, also did you illiminate the first 12 values for vqmap when you used the Z32 maf.

Your K value should be around 7A hex.Did you have the z32 maf hooked correctly?

Good luck,

PULSAR GTRRafi

rafi,

hes using live edit, and he is using the auto selction feature, you click the box for certain MAf, then a box for injector size.

after not running right on the Z32 and 550s he said that he tried to do a CA/Ka maf and 550s and it would still run like crap. im goin to see about a z32 on stock injectors to see if it works. try to narrow down the problem.

but my stock setup chip is running great he thinks the injectors arnt 550s but i looked up part #S and they are... i wont have time to mess with it again till this weekend.

[pulsar gtr]

Hi Not_a_sr,

I haven't had a chance to play with live edit yet, I do have the program but I haven't worked with it.

I am gonna try and write a program for the 550cc injectors and z32 maf and email it to you some time this week or next and If you can give it a try that would be great.

I will keep you posted.

Thanks,

RafiPULSAR GTR

[Not_a_sr]

rafi,

that would be great!! send it to [email protected], just put attn JON CA18det EPROMS.

we will probably be trying it again saturday or sunday. hopefully this time i dont have the fuel leaks like i did last time...