Fuel injected engines on Ultima?

[kuban]

Do people building Ultima use, fuel injected engine? I mean if you put the engine management from a CorvetteC5 engine? Or custome electronics like MoTec?

[mkoch1]

I am going to be running a tecIII www.getfuelinjected.com/ on my ls1 powered canam. It wasn't worth the money to modify the factory corvette harness to work has a stand alone unit. Any aftermarket unit will be more tunable and come with more features than the OEM set up.

mark

[eliotmansfield]

quite an intresting read (the pdf about the tec3), i dont understand this phase-sequential firing bit though, if i understand it correctly, it fires fuel in on the exhaust stroke?, surley that would double the fuel consumption????

>>>
From pg 72 of www.electromotive-inc.com/pdf_files/tec3.pdf:
>
Most applications will use the phase-sequential firing option. This firing scenario pairs
cylinders that share their TDC’s to the same injector channels. As such, one injector channel
fires two injectors: one on compression and the other on exhaust. Each injector channel will fire
once per revolution, so each cylinder will see a shot of fuel on both the exhaust and compression
stroke.

[BobM]

I think it does mean that - but that it injects it into the inlet manifold, and since the inlet valve is closed at that time the fuel mist hangs around till such time as the valve opens when it gets sucked into the combustion chamber.

I await correction

[eliotmansfield]

>>fuel mist hangs around till such time as the valve opens <<
Then it would run really rich, because it would put even more fuel in, when it was that cylinders 'turn'.
I'm confused..

Any idea how much these things cost anyway, i notice that they do a complete assly for sbc.
www.getfuelinjected.com/mpi_kits.html

It would sort out the "stalling under breaking" problem (i havn't got an ultima, but get similar probs with my carb on sbc, on my 4x4)

Eliot

[BobM]

eliotmansfield said:

Then it would run really rich, because it would put even more fuel in, when it was that cylinders 'turn'.

It delivers half the cylinder's charge each time.

[doc_fudge]

Does not sound exactly ideal!?!?!

Mark, how much do the tecIII units cost?

Have you considered a MoTec Unit?
From what I could gather on a quick read of the tecIII site, the Motec appears to be far and away more "tuneable".

If your already going to the trouble of fitting an aftermarket ECU, why not fit the best?

Just my 2 cents worth.

Andy

[davefiddes]

As far as I understand injecting onto the bak of a closed valve is not a bad thing. The fuel apparently has lots of time to vapourise and mix more fully with the air before the valve opens. You find this a lot in batch injection systems. I think this is one of the reasons why batch injection is not a huge amount worse than a full sequential system. Phased injection sounds like a useful step forward.

Once I've got my Ultima up and running and fully sorted I was planning to convert it from the boring ye olde carb to a batch EFI system based on the DIY MegaSquirt project (www.bgsoflex.com/megasquirt.html). Depending on how that goes I might then move up to a full sequential ignition/injection system powered by a DIY EFI332 board(s) (www.diy-efi.org/efi332/). Should be fun but perhaps not for the faint hearted...

[Menz]

I run a Jaguar V8 in the Ultima Spyder. The Motec M8 plus ignition expander drives all features of this modern engine, apart from knock sensors. The engine uses Denso electronics with on plug coils and inlet cam phasing.
Road tuning is possible using a wide band lambda sensor and the optional data logging. Trial software can be downloaded at the Motec website. The help screens are useful and there are pre programmed options for sensors, injectors, coils etc.
I am not advertising Motec, but can confirm that the system works well. I have found some frustrating bugs whilst tuning e.g. using inlet mass air flow, but managed nonetheless.
Which ever ECU you choose make sure it has enough features to drive your engine. A V8 engine has twice the number of injectors than a 4 cylinder. On plug coils need separate ignition outputs.
The end result is worth the effort.
David

[mkoch1]

From my understanding there are 4 types of injection

-Batch -
Cheapest, easiest to set up. Fires all 8 injectors at the same time, 2 times per engine cycle with no synchronization with the crank or cam position.


-Bank to bank -
Better more tunable. Fires one bank (4 injectors) at the same time 2 times per engine cycle with no synchronization with the crank or cam position.

-Phased sequential -
Better and more tunable than batch but requires a crank trigger. Fires 2 injectors in a pair, 2 per cycle. Once at top dead center intake once at top dead center exhaust. Needs to be synchronized with the crank position to know where tdc is.

- Full sequential -
Most tunable but requires a crank and cam trigger. Most expensive to set up. Fires one injector at tdc. Needs to be synchronized with the crank position to know where tdc is. Also need to be synchronized with the cam to know if it's on the intake or exhaust stroke.

In all cases you are not wasting fuel or running rich, you tune the car based on the amount of fuel being sprayed. Even though fuel is being sprayed when the intake is close, it just hangs around until the intake is open and then gets sucked in. The benefits come with how tunable they are. From what I have read phased sequential or bank to bank will work great and in most cases and it's not worth the time or money to go full sequential. Down side is the injector is firering more often than it needs to so the amount of time it is open is higher causing some pressure drop in the fuel system. On extremely high revving engines the injector may not have enough time to close between cycles.

I chose the tecIII because the tec systems where very popular with the RX7 guys (rotary engine) which I used to be into. One of the few boxes that can easily run split timing which a rotary needs. More importantly the company that makes the tecIII is about 1 hour from my house so tec support is good. The shop closest to me has installed and tuned hundreds of them so I feel confident tuning will not be an issue. I have heard good things about the haltech and motec units. Allot of guys with rx7's used to run haltech, but not many ever got it tuned correctly. I am sure any computer set up will work has long has you know someone that can tune it.

My set up ran about 2400 dollars. Includes 4 coils, computer, unterminated wiring harness, crank trigger wheel, mag sensor, software, heated o2, map sensor, power harness with fuses + relays, etc. Only problem was they don't make a crank trigger mounting kit for the LS1 so I had to have one fabricated.

I the carb conversion kit is around 3600 www.racerpartswholesale.com/electro4.htm comes with everything including manifold, fuel rail, injectors, and throttle body.

Not saying the tecIII is better than other options just the one I choose to go with. Any computer controlled system will be more tunable + efficient than carbs, not to mention all the other features you can control with the computer.

Mark

[jschwartz]

I'm running the GM ASA racing computer in my GTR. LS6 powered (ZO6 Corvette). It's not tuneable but it works well with the matching ASA racing cam, 38lb injectors and harness. It's fully sequential. I've now got 6870 miles since completing it in May and average 20-22 miles per US gallon. 438 rwhp on chassis dyno.

[ultimaandy]

jschwartz said:

I'm running the GM ASA racing computer in my GTR. LS6 powered (ZO6 Corvette). It's not tuneable but it works well with the matching ASA racing cam, 38lb injectors and harness. It's fully sequential. I've now got 6870 miles since completing it in May and average 20-22 miles per US gallon. 438 rwhp on chassis dyno.

Your engine really does impress me.... It's more powerful than mine, Lighter and yet doing nearly 10mpg more!
It seems this may be the combination of the furture. If you don't mind me asking, how much does the engine owe you and is it as easy to build as the old chevy?

[mkoch1]

does the LS1/LS6 already have a cam position sensor? If so I can probably just use that sensor to run full sequental with the TecIII.

mark

[pstockley]

My friend who put an LS1 in is GTR modified the stock camaro harness himself using a wiring schematics (he claims to know nothing about electronics). Turned out to be pretty easy. Then he got his ecu tuned by Agostino racing. They modified the code to remove fault codes due to the modified harness. They also ported and polished the heads and put a fairly mild cam in. Puts out about 460 to 470hp. Not bad for a engine costing under $10,000 CDN. There are a number of tuners in the US who should be able to remap the existing ECU for you.

[davefiddes]

Wonder how long it'll be before the pre-1974 emissions workaround is stopped by the UK Vehicle Inspectorate. When that happens I guess a most UK builders will have to go the LS1/6 route....and somehow squeeze cats in there too no doubt. Sounds like its a very capable platform though given the numbers being quoted here...

[jschwartz]

I've got $6000 in the engine, harness and computer, not including the stupidly expensive sheet alloy intake manifold. Bought a warranty core for $800 and built from there.
The LS does have a cam sensor located on the top rear of the engine, next to the oil pressure sensor. The crank sensor is in the side of the block down low, right side.
jeff

[doc_fudge]

Mark,

This is one of the things I love about this forum...many and varied opinions all with their respective pros and cons.

If TecIII is just down the road frorm you then its probably the best bet for you...after all, theres no point having a wizz bang ECU no one can tune for you!!

Please let us know how you get on.

As for building your own ECU....well, not for me!

MoTec is an Aussie company so would be a good bet for me. Besides, they also do a very nice dash/data logger which would make a great alternative to a stack dash.

Andy

[italiano]

The data logger looked like it had too much info, but then again, these aren't production cars.

Who really needs a dash anyway