DIY Fuel injection thread.

[NickJ]

7 hours ago, yoeddynz said:

I shall be chatting to you at Hanmer then ...

Sadly I've had another trip arise on the same weekend that will have me at the opposite end of the island, but PM me if you need some bits, can drop a few goodies in an envelope.

[ajg193]

I'll take whatever bits you have.

[yoeddynz]

2 hours ago, NickJ said:

Sadly I've had another trip arise on the same weekend that will have me at the opposite end of the island, but PM me if you need some bits, can drop a few goodies in an envelope.

OK cool !!!

[kws]

Ok, so quick update. Latest firmware on the Speeduino has a cranking enrichment table now, so depending on coolant temp it will alter the enrichment during cranking. The Rover starts much easier with lots of fuel when cold, and bugger all when warm.

I did move the crank sensor to about 0.55mm from the trigger wheel and its cleaned the cranking signal up a little. I still have some weird spikes in the trigger log for the first rotation of the engine which i think is confusing things. Its like the first 6-7 lines are all over the place and then they calm down.

[BlownCorona]

i cant find a straight answer anywhere. 

do i need a boost referenced fuel pressure regulator when adding a supercharger to a previously NA EFI engine, if i have a programmable ECU

setup is 

18RGEU

sc12 supercharger running somewhere between 5-10psi

upgraded to 450cc injectors 

megasquirt 1 ECU

 

[downtrail]

You will want to raise the fuel pressure with boost as there is a positive pressure now being applied to the fuel injectors outlet. The extra fuel pressure is to over come the pressure difference across the injector. 

 

So to make speed density tuning work well and be predictable. Yes you should have a boost refrenced fuel regulator.

[BlownCorona]

sweet thats the clear answer i wanted. thanks again!

 

[BlownCorona]

any sugestions on a good quality regulator? the market is flooded with chinese shit and i dont want to take any chances on my fuel system. 

 

[scooters]

Have a look at "volumetric efficiency tuning"  It is by far the most easy way to wrap your head around how a controller "thinks" and

how it gives the engine what it needs. VE is not new any more but it was never around back in the day. learning tuning and not using 

VE is just a awful prospect. 

[scooters]

Just now, Fliboi said:

any sugestions on a good quality regulator? the market is flooded with chinese shit and i dont want to take any chances on my fuel system. 

 

Turbo smart make great reg's that have been tested and documented. Don't get a shitty sard because the chance of you getting a real one and not a copy is slim. 

ps ali express has lots of shit regs if you want to go that way. 

[BlownCorona]

2 minutes ago, scooters said:

Have a look at "volumetric efficiency tuning"  It is by far the most easy way to wrap your head around how a controller "thinks" and

how it gives the engine what it needs. VE is not new any more but it was never around back in the day. learning tuning and not using 

VE is just a awful prospect. 

VE tuning is certainly what ill be using (and i think they only option megasquirt has) i have not yet started reading up on how to do it, all my tuning experience has been with carbs, but im very close to finishing the hardware setup! 

Edit - i certainly dont want to get a shit reg! the fuel system integrity is really going to be what makes or breaks (literally) this engine

[scooters]

Just now, Fliboi said:

VE tuning is certainly what ill be using (and i think they only option megasquirt has) i have not yet started reading up on how to do it, all my tuning experience has been with carbs, but im very close to finishing the hardware setup! 

Oh your megasquirt... your gravy then. So much back up from some real clever blokes. I think they have a auto tune feature now. Once it goes let it do it's thing and spend the next 5 years driving around with a lap top smoothing out the lumps and bumps.

[ajg193]

On 5/08/2017 at 08:03, yoeddynz said:

I shall be chatting to you at Hanmer then ...

 

On 5/08/2017 at 15:31, NickJ said:

Sadly I've had another trip arise on the same weekend that will have me at the opposite end of the island, but PM me if you need some bits, can drop a few goodies in an envelope.

 

I've ended up being a corporate shill and have gone the microsquirt route. If you two sort out what you want I can be the courier up to Hanmeet.

[kws]

What's an MS cost these days?

[ajg193]

Three arms and four kidneys. Gonna be more once customs holds it hostage.  

 

Was like 370 usd plus shipping. Also bought other bits so cost heaps

[flyingbrick]

https://www.aliexpress.com/item/Motorcycle-Universal-4-Carb-Carburetor-carburetter-Synchronizer-Set-kit-New/2038648083.html?spm=2114.search0104.3.34.wiP95P&ws_ab_test=searchweb0_0,searchweb201602_4_10152_10065_10151_10068_5400015_10307_10137_10060_10155_10154_10333_10334_10056_10335_10055_10054_5370015_10059_10332_100031_10099_5380015_10103_10102_5410015_5430015_10052_10053_10107_10050_10142_10051_10326_10084_10083_10080_10082_10081_5390015_10110_10175_10111_10112_10113_10114_10037_10312_10313_10314_10315_10078_10079_10077_10073_5420015-10332_10333_10102normal#cfs,searchweb201603_20,ppcSwitch_7&btsid=71289876-445f-4302-982f-1fb9b59b1209&algo_expid=c1ca2e46-ea63-44fc-b342-93061df5e95f-4&algo_pvid=c1ca2e46-ea63-44fc-b342-93061df5e95f

[Roman]

Since working down south at HPA I thought I'd start from scratch with a new tune file, my old one had lots of odds and ends in it from various experiements / adding and removing sensors etc. 

Looking at everything with a fresh set of eyes really showed how much a few things were garbage but I just assumed it was right when I didnt know much at the time or whatever.

Like looking properly into how the cold start functions work it's now much better, starts without foot on the gas and doesnt zing the revs up when you start it. 

As well as that I'd never really played around with accell enrichment before, now it feels a lot nicer at high rpm when you give the throttle a stab.

And I'll be ditching the staged injection as in my case it doesnt really add enough/anything to justify the added complexity to the fuel system, and the throttle response is worse when you're using it. I think to make it work as nicely as a single injector setup you really need a good wall wetting compensation model and two completely seperate tables for it for each injector.  Whereas the Link only has a single table for accel enrichment settings, and an initial enrichment setting when secondary injectors come on. Which makes it impossible to account accurately for situations where you've got say 20% secondaries vs 90%.

I think staged injection works well when your entire intake is hot, as it evaporates the fuel a lot quicker. 
But in my case when you've got a thermal isolator stopping engine heat soaking into the manifold you get a huge % of fuel ends up as wall wetting and you lose control of fueling and accel enrichment. 

I've now got about 3-4 sets of Altezza injectors though so I'm gonna flow bench them all and find the best matching set out of the lot. Will be interesting to see how much variation there is (or isnt) across that many of the same injector. 

Also just picking up this afternoon an Altezza engine in bits, so might throw it together and chuck it in the car to have a play around with exhaust side VVTI as well and see if that makes much difference compared to current setup.

/Pointless Dave Rant over  

/It's never really over though

[kws]

37 minutes ago, flyingbrick said:

https://www.aliexpress.com/item/Motorcycle-Universal-4-Carb-Carburetor-carburetter-Synchronizer-Set-kit-New/2038648083.html?spm=2114.search0104.3.34.wiP95P&ws_ab_test=searchweb0_0,searchweb201602_4_10152_10065_10151_10068_5400015_10307_10137_10060_10155_10154_10333_10334_10056_10335_10055_10054_5370015_10059_10332_100031_10099_5380015_10103_10102_5410015_5430015_10052_10053_10107_10050_10142_10051_10326_10084_10083_10080_10082_10081_5390015_10110_10175_10111_10112_10113_10114_10037_10312_10313_10314_10315_10078_10079_10077_10073_5420015-10332_10333_10102normal#cfs,searchweb201603_20,ppcSwitch_7&btsid=71289876-445f-4302-982f-1fb9b59b1209&algo_expid=c1ca2e46-ea63-44fc-b342-93061df5e95f-4&algo_pvid=c1ca2e46-ea63-44fc-b342-93061df5e95f

Thats more than i paid for my Carbtune Pro off trademe. Cmon Ali, you can do cheaper than that.

[flyingbrick]

Oh I thought it was cheap... Soz 

[Roman]

I decided to start from scratch with a tune file, I've fairly well hashed out the 0-4000rpm region in all load regions of the fuel map. Because you go through all of them all of the time when driving. But I've found it difficult to reach the higher rpm mid/low load areas (partially because you're never in them) and I never felt confident in the past that I had these accurately set.
So for interests sake, I thought I would software limit the e-throttle angle so 100% on the pedal is only say 80% TPS or whatever. 
Then go do some "full throttle" runs, where I could get consistent and repeatable results to help dial in the fuel in those part throttle areas. 
However, the results really surprised me! I had to pull out so much throttle angle just to lose 10kpa of manifold pressure. 
It was a good exercise to complete as it felt like my accel enrichment has been relying on these load cells that havent really been dialled in too well. 
But found it very interesting how non linear the MAP vs TPS relationship is at higher RPM. 
This car has a factory Toyota Altezza E-throttle unit which from memory is 78mm at the butterfly so you can tell that it obviously causes very little restriction even when partially shut.
I would expect a more linear TPS vs MAP relationship when using a smaller throttle body.
In other news, its hilarious doing a full throttle run at 20% throttle, it takes a long time hahaha.