E85 Fuel & Larger Injectors

[Shane001]

I'm looking for a piggyback ECU for my Mits FTO racecar and interested in the Haltech.

This car very likely will be running 2 tunes by the end of the year, one for standard PULP98 (for when E85 is not available), the other for E85. To run E85 I'll probably need to upsize the fuel injectors (and fuel pump) as I expect I'll need to run approx 30-40% more fuel. This is an NA engine, not turbo charged. Will the miniceptor be able to handle pumping in this much extra fuel?

Thanks.

[LMS_689]

Theoretically, if you upsize the injectors the appropriate amount then the pulse width required to maintain a common a/f ratio would not change. So, in practice it will require only a minimum of injector offset if you size the injectors appropriately for the E85 fuel. When going back to gasoline you will need a map that pulls 25%+ from the programmed injector on time since you have upsized the injectors. This is no problem for the Miniceptor, just make sure your injectors are going to be happy with this shorter pulse width.

[Mitsiman]

This won't work with the minicepter. You will easily go outside of its tuning range, as E85 requires usually 30% more fuel on average.

The other problem is E85 has vastly different cold start characteristics compared to petrol fuels and you need to do a lot more mapping on air tempature settings.

I highly recomend for what you are wanting to do, go to a Haltech E8/E11 if you want something cheaper or the newer PS1000 / 2000 system if you can afford it. We have successfully run Haltechs on the FTO vehicles without any difficulties.

[Shane001]

Thanks guys, but I now have 2 somewhat conflicting answers lol.

Mitsiman, do you not agree with what lms_689 suggested about the injector sizing? And from reading the manual doesn't the Interceptor allow + or - 100% fuel? So 30% for E85 should be no issue?

Also remember this is a track only car, not registered and never to be driven on the street. So cold starts are not a big deal (as long as it does actually start lol) as it won't be cold for long. Other than around the pits, the car will spend 98% of it's time between 4000 & 8000rpm.

It's also a very low budget racer, which is why I'm looking at a piggy back rather than full ECU. Cheaper to purchase, cheaper/easier to install, and cheaper/easier to tune. The other option I'm looking at (can I say this on here) is the eManage Ultimate. Not sure how they compare though. I'd prefer the Haltech as several of the NSW forum members have these with good results. Still checking out the capabilities though. The manual & the website are a bit thin on detailed capabilities. Need to draft an email and send to Haltech support.

More advice welcome

[Mitsiman]

Remember the piggy back is trying to trick the ECU. The more you try to trick it - the more adjustments you make and the more out of sorts the factory ecu gets.

Trying to tune a car with more than 25% changes would just create havoc on the tune. Remember you are telling the ECU that the airflow volume is now lower than what it really is. This means that all functions controlled by the ecu, including idle speed, ignition timing, deceleration etc are all now reading incorrectly.

It also means you wll have to do a very detailed ignition map which alters the crank angle sensor, which then effects the injection angles ...... do I need to go further.

The piggy back is fine for its desired use - stock injectors with minor tweaking using adjustments up to 25%. As soon as you go over this or start adding larger injectors - your asking for trouble.

You say your a low budget racer - then I ask you this - can you afford to blow your engine up and replace it because you have compromised the factory ecu too much?

WHich is cheaper - waiting a little longer, and getting a proper ecu or using a piggy back now? Remember the Sprint 500 is not far off hte pricing of a miniceptor and will do everything better without compromises. Sure it will cost more to tune and install, but in the long run, it will be cheaper, more effective and far far safer for racing.

As always its a personal call and everyone has there own opinions, but I tried using piggy back computers and larger injectors on my race car on normal pump fuel, and after 3 blown engines, went to a haltech full ECU and never blew an engine since. When I datalogged the AFR's on the track I realised how many area's of the tune the piggy back could not compesnate properly for.

[Shane001]

Hmm more food for thought, thanks very much for your feedback mitsiman.

I really need to know more about the Interceptor before I make a decision anyway, still have a lot of questions. I think I'll probably steer clear of E85 for the short term, the gains for an NA engine are no where near the gains for a Turbo engine anyway, and I'm not after the last drop of hp, I'm just after a little bit more to get me up the hill at Bathurst at Easter lol! And I want to keep this car as simple as possible. I learned from my last car that the more you do, the more you have to do, and the more it just keeps costing you in time and money...

I'll be installing a wideband afr sensor and guage, which I planned to connect up for logging.

Better send off an email to haltech for some answers first I think.

Thanks guys.

[HaltechScott]

Platinum Sprint 500.