Stand Alone vs. Piggyback - Help me understand

[RYU]

Lately, I've had a few friends (and stories on prime) encounter problems with their EMS to a point where I personally would likely throw in the towel. I also understand that once you make the decision to up the HP you're sacrificing OEM bulletproof reliability. EMSs (and engine builds in general) are something i've avoided over the years because I do not take for granted that my car simply starts and I can just go.

What if someone decides to go FI or NA build? For a NSX producing around 350+ to <400hp (my target goal) what are your suggestions to address the need for added fuel management? For 400hp+ I can certainly understand the need for a full EMS but some of us are not looking to do that.

I have a piggyback Split Second unit on my daily-driver TRD SC V6 controlling a 7th injector. It's been absolutely bulletproof for 30k miles and I installed the blower with already 100k on the odometer. I like the fact that the primary tune is OEM so it's smooth at idle/startup/low rpms but adds more fuel via the extra injector when needed. I'd love to get this type of reliability and stock-like characteristics for an NSX. How are piggybacks in general working for the NSX? I don't see many folks adding an extra injector (for low HP builds) but instead up their injector sizes instead which will likely require a new map? I know some of you will say just get a low boost CTSC but i'm not sure about that for my driving style. I'd likely heatsoak that with my newbie skills at the next HPDE and not sure if I like the throttle response on an SC yet.

Perhaps I should ask the question a different way. With reliability and engine safety as the top concern, what type of fuel management system would you use for a ~350hp build on the NSX? Would the question be answered a different way depending on what power adder was used (i.e. NA build, ITBs on stock motor, SC, Turbo/Twin Turbo)? Also, why do some tuners dislike tuning piggybacks in general?

Pardon the newbie questions. I'm all over the place today.

 

[funkynsx]

Ive recently had delivered from science of speed a supercharged FI stage 1 engine built for me that puts out 420 rwhp.
I have also bought the AEM EMS stand alone computer aswell.
the good thing about the AMS EMS is it's plug and play. no wiring harness is needed.
Also sos give you 80 to 90% of the tuning.
as long as you have a good tune it should be fine.
sos recommend this ECU for high boosted set ups.
Ive also previously worried about reliability but all my research suggests with a good tune reliability should'nt be an issue.
It's quite a strong engine the nsx has. titanium con rods standard. you got to like that.:smile:

 

[CDX_NSX]

If you're going to go FI, proper management is absolutely key. I don't think that it matters if it's S/C, tubro, or NA, and I don't think that the method would differ between each or what power levels you're aiming for. As you know, I run the AEM EMS, and for the most part it has been trouble-free; it really comes down to the tune. After speaking with Tino and Manny yesterday, my recent troubles may not be AEM related. In fact, I'm leaning towards it not being AEM related being that I've been running it in its current configuration since the end of 2008 without any issues. I do have to investigate further to be sure of what the trouble was, though.

Another option that I had considered was to run the HKS F-Con as a piggy-back to the OEM computer, but this was really for reasons other than reliability of the AEM.

I'm not sure why some tuners don't like tuning piggy-backs, but I'm sure that there are more than a few NSXs running successfully on the FIC. A friend of mine was successfully running the FIC on his track NSX pushing about 450.

 

[ScienceofSpeed]

I'm not sure what problems your friends have had, however, the AEM EMS has clearly become the most widely accepted and used stand alone EMS for the NSX. In our experience, it is highly reliable and offers functions that put it in line with higher end systems costing 3-4 times as much. Unlike every other systems, it is plug and play.

Stand alone systems tend to be preferred by tuners because they offer the most control compared to piggy back systems which simply intercept functions such as pulse width to injectors - and may be influenced by the factory ECU, especially in transition into positive (boost) pressure.

This system, like all EMS, is a "blank sheet of paper" - meaning the success of the tune is highly dependent on the tuner's abilities and familiarity with the system. The system is so well refined now - existing problems are most likely setup / tuning related. With the EMS, we have completed tunes on "all factory" 3.0L up to twin turbocharged 750 horsepower tubocharged 3.5L. All run as close to a factory engine as one could expect. At ScienceofSpeed, we have a library of base calibrations that can get you up and running with the EMS immediately. In addition, because of the wide use of the AEM EMS, it is by far the most common EMS for tuners to have experience with in the USA, and now becoming, worldwide.

We offer the AEM EMS for the 1991-94:
http://www.scienceofspeed.com/products/engine_performance_products/NSX/AEM/EMS/default.asp

And now offer the AEM EMS for the 1995-2005:
http://www.scienceofspeed.com/produ...roducts/NSX/ScienceofSpeed/EMS_1995-2005_NSX/

Let us know if you have any questions.

regards,
-- Chris

 

[E-Nough Logic]

If you're going to go FI, proper management is absolutely key. I don't think that it matters if it's S/C, tubro, or NA, and I don't think that the method would differ between each or what power levels you're aiming for. As you know, I run the AEM EMS, and for the most part it has been trouble-free; it really comes down to the tune. After speaking with Tino and Manny yesterday, my recent troubles may not be AEM related. In fact, I'm leaning towards it not being AEM related being that I've been running it in its current configuration since the end of 2008 without any issues. I do have to investigate further to be sure of what the trouble was, though.

Another option that I had considered was to run the HKS F-Con as a piggy-back to the OEM computer, but this was really for reasons other than reliability of the AEM.

I'm not sure why some tuners don't like tuning piggy-backs, but I'm sure that there are more than a few NSXs running successfully on the FIC. A friend of mine was successfully running the FIC on his track NSX pushing about 450.

That is a simple question to answer. The stock ECU is always adapting and changing which can throw off a tune. As long as the stock ECU is in the car controlling fuel and timing in any manner there is an unknown variable changing based on the cars conditions and cannot always be accounted for in the piggy back system. For example if the ECU sees a rich condition because of positive pressure(remember the stock ECU is tricked into thinking its at 0psi) it might want to pull fuel that the engine needs.

Lately, I've had a few friends (and stories on prime) encounter problems with their EMS to a point where I personally would likely throw in the towel. I also understand that once you make the decision to up the HP you're sacrificing OEM bulletproof reliability. EMSs (and engine builds in general) are something i've avoided over the years because I do not take for granted that my car simply starts and I can just go.

What if someone decides to go FI or NA build? For a NSX producing around 350+ to <400hp (my target goal) what are your suggestions to address the need for added fuel management? For 400hp+ I can certainly understand the need for a full EMS but some of us are not looking to do that.

I have a piggyback Split Second unit on my daily-driver TRD SC V6 controlling a 7th injector. It's been absolutely bulletproof for 30k miles and I installed the blower with already 100k on the odometer. I like the fact that the primary tune is OEM so it's smooth at idle/startup/low rpms but adds more fuel via the extra injector when needed. I'd love to get this type of reliability and stock-like characteristics for an NSX. How are piggybacks in general working for the NSX? I don't see many folks adding an extra injector (for low HP builds) but instead up their injector sizes instead which will likely require a new map? I know some of you will say just get a low boost CTSC but i'm not sure about that for my driving style. I'd likely heatsoak that with my newbie skills at the next HPDE and not sure if I like the throttle response on an SC yet.

Perhaps I should ask the question a different way. With reliability and engine safety as the top concern, what type of fuel management system would you use for a ~350hp build on the NSX? Would the question be answered a different way depending on what power adder was used (i.e. NA build, ITBs on stock motor, SC, Turbo/Twin Turbo)? Also, why do some tuners dislike tuning piggybacks in general?

Pardon the newbie questions. I'm all over the place today.

You won't see this on many setups because it is less than ideal, it also needs its own fuel line. Typically these systems don't control timing and just deal with stock timing values with the positive pressure. Also it depends on how the ECU measures the air coming in. If it is a MAF setup some of these are a bit more adaptable than the NSX's MAP setup which freaks out when seeing positive pressure.

The AEM EMS is a fairly reliable system. Aside from the small problem where you have to give the ECU 3 seconds before it will let you start the car should start and idle like stock. If you or your friends are having serious issues I wouldn't be quick to blame the ECU but maybe the ECU needs to be used properly.

 

[RYU]

Thanks for the reassuring comments gents. Perhaps i'm putting too much misplaced blame on the EMS itself. It could be definitely other things that go wrong along with a high hp build. Thanks also for the tid bits on the piggyback.

...still struggling with getting a comfort level for power adders to the NSX though I would want something extra for next year.

 

[goldNSX]

I'd likely heatsoak that with my newbie skills at the next HPDE and not sure if I like the throttle response on an SC yet.

The throttle resonse of the very common CTSC very, very similar to OEM, only a tad slower, nothing to worry about.

Also, why do some tuners dislike tuning piggybacks in general?

I can't second that but maybe it's because tuners like to earn money.

 

[kookoo4nsx]

I run the AEM F/IC piggyback. Zero problems since installed. Starts and idles like stock. All comes down to the tune. It's my personal opinion that many issues not related to F/IC and EMS are blamed on engine management.

 

[MetalSpikeRacing]

I am running AEM EMS, car start at the very first single key turn.
And idle its great, you wouldtn ever now I had an EMS in there.


-MSR

 

[stevenlee]

I am running AEM EMS, car start at the very first single key turn.
And idle its great, you wouldtn ever now I had an EMS in there.


-MSR

How are you able to get the engine to start immediately without having to wait a few seconds?

 

[Cozmo]

I got into the habit of turning the key to prime the fuel pump,then putting on my seatbelt. It is ready to go by the time I am.