Arc2 & 92mm MAF or 98/99 ECU and Evo MAF

[NickS VR4]

Currently running 13Ts, and 550cc injectors. I have Arc2 and 92mm MAF but was curious of others thoughts. Which would be better for my current setup as well as a possible dr750 upgrade down the line?

What would be the pros and cons of each?

I haven't selected a boost controller yet, so would the flashable ecu be better paired with the lcdboostcontroller?

Fyi my car is a 94

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[Goallie11]

I'm running dr650's (old style) with 550's and an emange blue which I'm beginning to hate. I think the absolute best tuning option for us now is a 98/99 ecu and evo maf. You don't see evo's running any piggyback type system, just evoflash or aem's.

[keo92stealth]

how much would it cost to go with the 98-99 ecu and the evo maf? you probably could get a arc2 cheaper if its used. and they say its easy to tune. i will find out how easy it is to tune in a few days hopefully.

edit: but i dont know man, those flashable ecu gives you a ton of options. pretty much just like a standalone if you have timing\igniton control and launch control.

[TurboSinceBirth]

I have both except for the EVO MAF. I plan to use the ARC-2 with the 98 SL ECU or maybe at the very least try out the EVO MAF for a little while. I don't have the flashed ECU installed yet. The ARC-2 is super simple to tune. It's limited to 720cc injectors though and for my plans DR-750 turbos or bigger on E85 I need at least 1200cc injectors which won't work on the ARC-2. Plus I wanted more fine tuning and adjustability.

If you want a tuning solution that will get it done with the least amount of work the ARC-2 is what you want. If you want OEM driving on a modded car plus more tuning ability than any piggyback get the flashed ECU setup. The EVOs have pushed their MAFs to 700AWHP and we don't know yet how far they'll go on a 3.0L. What scares me is the EVO MAF coming apart when you're pushing a huge amount of power because if you're like me you can't afford a $2500 rebuild on DR-750s after you already spent $3600 on them the first time only because some plastic pieces or the honeycomb MAF flew into the compressor wheel.

[keo92stealth]

I have both except for the EVO MAF. I plan to use the ARC-2 with the 98 SL ECU or maybe at the very least try out the EVO MAF for a little while. I don't have the flashed ECU installed yet. The ARC-2 is super simple to tune. It's limited to 720cc injectors though and for my plans DR-750 turbos or bigger on E85 I need at least 1200cc injectors which won't work on the ARC-2. Plus I wanted more fine tuning and adjustability.

If you want a tuning solution that will get it done with the least amount of work the ARC-2 is what you want. If you want OEM driving on a modded car plus more tuning ability than any piggyback get the flashed ECU setup. The EVOs have pushed their MAFs to 700AWHP and we don't know yet how far they'll go on a 3.0L. What scares me is the EVO MAF coming apart when you're pushing a huge amount of power because if you're like me you can't afford a $2500 rebuild on DR-750s after you already spent $3600 on them the first time only because some plastic pieces or the honeycomb MAF flew into the compressor wheel.

so you dont think 1000cc injectors and e85 wont max out 750's? i already know ill be maxing out on fuel way before my setup taps out.

[TurboSinceBirth]

so you dont think 1000cc injectors and e85 wont max out 750's? i already know ill be maxing out on fuel way before my setup taps out.

No I don't think so seeing as how they didn't max out DR-700L turbos either. The turbos still had some left in it. Steve said he needed 1200cc injectors because even with the fuel pressure turned up he was still out of fuel at 600AWHP. If you turn up the fuel pressure on the 1000cc injectors with the ARC-2 you're making them act even bigger. Even with the ~30% extra fuel required 1000cc injectors are going to stretch the limits of the ARC-2 on ethanol. My Denso 720cc injectors flowed 690-700cc. I don't think I'd run E-85 on 1000cc injectors with the ARC-2 alone. The problem you'll probably find trying to correct the fuel to hit the leaner AFRs you want with ethanol is that one click to the left makes it too lean and one click to the right makes it too rich. Each click makes a percentage change in fuel. As you approach the 720cc gas injector limitation of the ARC-2 you lose any fine adjustability. Even on 550s I wish I had a little more. The car still runs fine though. I now have a little more time to spend towards tuning my car so I don't mind moving towards a more complex engine management. Plus it won't handle the injectors I have planned anyways.

For the ARC-2 stick to 720cc or smaller on pump or race gas. If you want to try ethanol 1000s should work but like I said it's the same problem with 720s is that you can't fine tune the fuel corrections with the device alone. The car will run fine but you are leaving some power on the table. For those that want to tune their car in 15 minutes they don't care about leaving power on the table.

[keo92stealth]

No I don't think so seeing as how they didn't max out DR-700L turbos either. The turbos still had some left in it. Steve said he needed 1200cc injectors because even with the fuel pressure turned up he was still out of fuel at 600AWHP. If you turn up the fuel pressure on the 1000cc injectors with the ARC-2 you're making them act even bigger. Even with the ~30% extra fuel required 1000cc injectors are going to stretch the limits of the ARC-2 on ethanol. My Denso 720cc injectors flowed 690-700cc. I don't think I'd run E-85 on 1000cc injectors with the ARC-2 alone. The problem you'll probably find trying to correct the fuel to hit the leaner AFRs you want with ethanol is that one click to the left makes it too lean and one click to the right makes it too rich. Each click makes a percentage change in fuel. As you approach the 720cc gas injector limitation of the ARC-2 you lose any fine adjustability. Even on 550s I wish I had a little more. The car still runs fine though. I now have a little more time to spend towards tuning my car so I don't mind moving towards a more complex engine management. Plus it won't handle the injectors I have planned anyways.

For the ARC-2 stick to 720cc or smaller on pump or race gas. If you want to try ethanol 1000s should work but like I said it's the same problem with 720s is that you can't fine tune the fuel corrections with the device alone. The car will run fine but you are leaving some power on the table. For those that want to tune their car in 15 minutes they don't care about leaving power on the table.

yea and i think steve was only using a afc? correct me if im wrong. idc care the fuel corrections for now. i just want it to run ok. also, mines are 950 cc.

also, how would you tune the flash ecu?

[mb3000]

To run larger than 720cc on pump gas with the ARC2 you wire in a SAFC before the arc2 and make a "mainscale" adjustment, and use the arc2 for the tuning.

Hell, you could use both of them to tune.

[TurboSinceBirth]

yea and i think steve was only using a afc? correct me if im wrong. idc care the fuel corrections for now. i just want it to run ok. also, mines are 950 cc.

also, how would you tune the flash ecu?

Steve was using a MAFT and SAFC so he could make enough corrections to run it. The problem with stacking piggybacks is that if you run very large injectors you end up getting lower IDC if they're not properly selected plus it throws more complication in there for the ECU and can mess up your timing i.e. you're in a completely different part of the map than you should be.

I'm not as huge of a fan of using multiple piggyback controllers now especially when there's a flashed ECU option available that will replace them all. Before you had to get a standalone which was a huge investment not only in the device itself but in tuning also. In theory you should be fine running the ARC-2 on 950cc injectors with ethanol. If you ever want to put pump gas in you'll be screwed. I'm just going off experience tuning Denso 720s with the ARC-2.

There's definitely a noticeable difference in adjustment between 550s and 720s with regards to how much correction a click makes. If you're not picky about your car you will probably love the ARC-2 with your 950cc injectors and ethanol because it's so simple and works. Otherwise, you may decide to fine tune things later down the road if you feel comfortable doing it yourself in which case you can swap in a SAFC2 to help like Matt did tuning 1000s on race gas with the ARC-2 and SAFC2. He spent over 30 dyno pulls dialing it in though where it was dead on where he wanted it.

The learning curve for the flashed ECU is higher than the ARC-2 but it isn't overly complicated. You don't have to tune everything on the car from scratch like a standalone. A good portion of the tables on the stock ECU won't need to be touched. It has a way that you can input your injector size and through manipulating that you get your fuel trims close to where they should be by adjusting the injector size up or down. From there you can fine tune the fuel map. There's plenty of threads on here about tuning a flashed ECU so if it's something you're interested in I suggest searching since it's all laid out. The ARC-2 is a good tuning device for beginners since it takes no time at all to setup and dial in.