AEM EMS II question

[USAFguy22]

So I'm going to buy AEM EMS Series II in the near future because I'll eventually need it for my long term goals (changing compression + engine rebuild) and am wondering if I will see any gains over my current setup.
Right now I have:
CT intake box with Uni filter
SoS big bore TB
RDX injectors w/ stage 3 reflash
Brand new IAT sensor
RAN UP RS-R
CT headers
Prospeed Hi Flo cats
Pride V1
Recently changed tranny/diff fluid
Prospeed Insulating gaskets
ATI harmonic damper

I guess what I'm getting at is; will this yield more gains than the Prospeed ECU reflash? I don't think I'll do individual cylinder tuning because I dont want to deal with removing the headers (nightmare!)

Looking forward to hearing your guys' input

 

[USAFguy22]

No one?

 

[L_RAO]

It's a tough question to answer as most of the guys who "need" an EMS are FI guys.

To go from a Prospeed-style reflash to a full EMS + tune, you're talking about a 4-digit difference. My current understanding is that there is no benefit, at least for most NA cars, to justify the price jump.

 

[Valhalla]

L_RAO is correct. The AEM Series II will replace your ECU and while you might a gain a little through timing, the cost is prohibitive unless you are printing your own money. It truly is meant for stand alone FI applications and any gains you see will be minimal at best.

 

[USAFguy22]

I'll need it when I change the compression and do head work, that's my only reason. Also may go ctsc at some point so that's my reason for getting it. I was just curious if I would see any gains in the mean time

 

[ScienceofSpeed]

Based on your future goals, you'd likely need an EMS. So, I think you should consider if you do the reflash now, then buy the EMS in the future, you'll be out of the cost of the reflash & EMS. Where as if you buy the EMS now, you'll be out only for the EMS. We have these guys in stock, if you're interested!

http://scienceofspeed.com/products/engine_performance_products/NSX/ScienceofSpeed/EMS_1991-94_NSX/

 

[L_RAO]

Based on your future goals, you'd likely need an EMS. So, I think you should consider if you do the reflash now, then buy the EMS in the future, you'll be out of the cost of the reflash & EMS. Where as if you buy the EMS now, you'll be out only for the EMS. We have these guys in stock, if you're interested!

http://scienceofspeed.com/products/engine_performance_products/NSX/ScienceofSpeed/EMS_1991-94_NSX/

What part of the OP's future plans necessitate the EMS? The increased compression? The rebuild? For the most part, his list of parts look like a standard NA build (a bunch of bolt-ons). I'm not trying to be argumentative, I would simply like to learn something.

My biggest frustration with the EMS is that no one (not even AEM) can tell me what functional differences it offers over the reflash in an OBD-1, NA application.

Timing?
Fuel curves, injector size?
VTEC crossover?
Rev limiter?

These are the biggest things I can think of off the top of my head, and these are all things that the reflash can accommodate.

 

[Ko-nsx]

What part of the OP's future plans necessitate the EMS? The increased compression? The rebuild? For the most part, his list of parts look like a standard NA build (a bunch of bolt-ons). I'm not trying to be argumentative, I would simply like to learn something.
.

Post #5 states he may want a supercharger.

 

[USAFguy22]

Based on your future goals, you'd likely need an EMS. So, I think you should consider if you do the reflash now, then buy the EMS in the future, you'll be out of the cost of the reflash & EMS. Where as if you buy the EMS now, you'll be out only for the EMS. We have these guys in stock, if you're interested!

http://scienceofspeed.com/products/engine_performance_products/NSX/ScienceofSpeed/EMS_1991-94_NSX/

Yes I'll be buying from SoS. And for the engine rebuild as well I am interested in your stage one rebuild. Now I also have a few questions:
With the rebuild, it sounds crazy, I'd like to bump up compression slightly. How much is safe for 91 pump gas? As I know IAT's will certainly be higher.
10.5:1 w/ 6lb CTSC?
11:1 w/ 6lb CTSC?
10.5:1 w/ 9lb pulleys?
Another goal is to increase RPM, would 8500 or even 9k be possible with:
The rebuild
Balanced rotating assembily
Billet oil gear set?
Will this require valvesprings/retainers/bases/LMA/and valves to reach my goal?

Post #5 states he may want a supercharger.

Correct, and since I have RDX injectors I'll need EMS to configure the CTSC.

 

[ScienceofSpeed]

What is the reason you wish to increase compression with a supercharger? We would not recommend increasing compression for use with a supercharger and 91 (R+M)/2 octane fuel - there will be no benefit and knock control will be difficult making reliability of the engine suffer.

With the increased rev limit, there will be no benefit for increased power, as the engine (and supercharger) reach their mechanical and flow capacity at the current rev limit. Meaning, if you increase the speed of the engine, there will be no gain to have in power.

Hope this makes sense, feel free to give us a call if you have any questions.

regards,
-- Chris

 

[USAFguy22]

What is the reason you wish to increase compression with a supercharger? We would not recommend increasing compression for use with a supercharger and 91 (R+M)/2 octane fuel - there will be no benefit and knock control will be difficult making reliability of the engine suffer.

With the increased rev limit, there will be no benefit for increased power, as the engine (and supercharger) reach their mechanical and flow capacity at the current rev limit. Meaning, if you increase the speed of the engine, there will be no gain to have in power.

Hope this makes sense, feel free to give us a call if you have any questions.

regards,
-- Chris

Could the powerband be extended at all with your FI cams? Or are they the same lift as OEM?

 

[ScienceofSpeed]

The lift is increased with our cams, however, I don't think cams will change the powerband as it has more to do with the efficiency of the supercharger and manifold. However, when you shift at the existing rev limit (or even sooner), you're still within the peak torque of the supercharged engine - so maybe I am confused at what your goals are. Please give us a ring to discuss.

 

[dynomike]

When going to a AEM EMS over the stock computer with a nsx that is out fitted with headers and exhaust, I typically see around 15whp made through out the the mid range and around 8 to 10 at the top. I did some back to back testing between this reflash and stock computer and the stock computer on our test car actually yielded more power. Then we put our tuned AEM EMS Series 2 on the car and picked up the above power. The ems will allow total control over the way the engine is tuned. It is up to an experienced tuner to find where the power is to be had. Aem simply gives us a tool to use to find the power.

 

[ScienceofSpeed]

Well put Mike. To clarify, are you saying the factory calibration yielded more power than the reflash?

-- Chris