XMS

[Hennie Marais]

I've been doing a lot of research on the management systems that's available and I have to say, the XMS is a very nice system, maybe not the most user friendly around but it's the closest you'll get to a OEM EFI. So even if it's one off the most expensive "local" systems, I still think it's worth it. It's currently on my number 1 position for my current project, only because this project must remain a fully "street" car.

[Hennie Marais]

there's just one thing I don't like about the system, I don't like tuning with the TPS and compensating with the MAP.

[The Calibrator]

there's just one thing I don't like about the system, I don't like tuning with the TPS and compensating with the MAP.

Its far from perfect but for the money its a good system if you want significantly better then you start to look at over spending over 10k.

ALL the "proper" management systems use tps and map to tune its the only way to get a decent tune.
Map only systems have unstable idle, no accel enrichment and poor fuel economy.
TPS only works but cannot be used on forced induction and still lacks a bit of refinement.

[Hennie Marais]

[quote="The Calibrator
ALL the "proper" management systems use tps and map to tune its the only way to get a decent tune.
Map only systems have unstable idle, no accel enrichment and poor fuel economy.
TPS only works but cannot be used on forced induction and still lacks a bit of refinement.[/quote]

I know most fancy systems use TPS and MAP, I would have like it if you could tune it according to the MAP sensor and just use the TPS for idling and WOT, maybe a few inbetween.

Most systems that use MAP sensor have got acc enrichment, it's set to a % change in vac/boost with a %enrichment, even the old domingos had it. The only problem I've had with MAP only systems and idling is when you start running aftermarket cams, then the vacuum signal at idling is a bit low making it difficult to idle smooth.

[jon]

Hi Hennie

Thank you for the info, if possible could you please post a link to specs?

[Hennie Marais]

www.perfectpower.com

You can go have a look there.

[jon]

Thanks Meneer

Price seems really competitive vs the amount of features you get, especially when compared to some of the foreign stand alones, very interesting.

[qewrty]

Thanks Meneer

Price seems really competitive vs the amount of features you get, especially when compared to some of the foreign stand alones, very interesting.

I can't comment much for two reasons. One I haven't had a go with my XMS, yet. The logging and PC software seems to be of a higher standard than some of the other options I've seen. Two, I can't comment is because I just wouldn't know what I'm talking about. I was honestly convinced that a Mr Turbo would be fine, but now I'm enlightened..obviously there are many options that will run but with VVT and all I think the XMS.

But the ECU's performance is relative to the tuning, or the ability of whoever does your tjooning, but it sounds like you guys have done this before. I can't wait to see your cars Variety is the spice of life after all!

[veecee]

go take a free ride in dislex's s14. then you will realise that the XMS is ohh-kay!!!

i did and i was very impressed!

[WooHaa]

I have also now been to the perfect power website & checked out the smt7 piggyback system.

The questions I have are,
1) If the manufacturer spends so many hours making different maps, does the piggyback add to those maps or does it replace them completely.

2) The mods I have are not as intensive as some of the guys here & I have just concentracted on freeing up air going into & out of the engine. Do I need a full Managment system or is a Piggy Back enough.

3)there is a company called ATC Tuning, who will also do somehing to a stock 200SX & give it an extra 15KW on the wheels for about R2500.00, Is thispossible just by chipping?

4) If a piggy Back or Chipping is just re-tuning the signals to the stock ecu, then will all piggy backs be the same. Uni-Chip, perfect power etc.

okay, I'm done.

[Hennie Marais]

The piggy back systems is mostly used by guys that don't have major mods done, airfilter, freeflow and maybe a small turbo upgrade. What it does is it takes the stock sigmals of the factory ECU and "modify" it to compensate for the changes made on your engine. So if you need say 10% extra fuel at x rpm you adjust the piggyback to change the signal to add that specified amount. Same with the timing if the piggyback can do timing. Only problem with a piggyback is that you can only work within the factory ECU parameters,

[The Calibrator]

As stated the Piggyback modifies the maf or map and timing signal.
You either raise or lower the load voltage and slow down or speed up the ign signal. On some cars you interrupt the signal in to the ecu ie most crank triggered systems on the hall effrect cars you normally interrupt the signal to the coil ignitor.

you can ONLY use the SMT7 on crank trigger systems which exludes most Nissans.

Hennie map sensor based systems are a pain to map. Once you have worked with a semi decent system you will understand the limitations of map only based systems.

They are quick and nasty to map if you dont really care about the outcome the tps/map based systems give you so much more adjustability and smoothness if you are willing to spend a little bit of time on them.

Why do you think I take 3 days to a week to map a stand alone system.

[WooHaa]

@Calibrator.

What would you suggest for my purposes.
I got an S13, with the turbo modfied with a slightly bigger compressor wheel, which came off an s14(167kw)
I got a full 63mm Stainless steel exhaust, with one small back box.
s14 downpipe.
increased fuel pressure......Don't know how much.
Cone filter.
Waiting for the front mount intercooler.
I then want to tune the sucker, do you suggest a chip or full management system?
My requirements are that the car must be drivable through out the rev range, & must'n have so bad lag as it does now.

My idle Kilowatt output must be 140KW on the wheels....achievable?

[widowmaker]

probably not while its idling...
unless you "advance" the sucker a helluvalot but then you'll get 0.5 km/L

[Hennie Marais]

Hennie map sensor based systems are a pain to map. Once you have worked with a semi decent system you will understand the limitations of map only based systems.

They are quick and nasty to map if you dont really care about the outcome the tps/map based systems give you so much more adjustability and smoothness if you are willing to spend a little bit of time on them.

Why do you think I take 3 days to a week to map a stand alone system.

I know it's beter to use a combination of the 2, I just prefer to use tune with more map site and just compenstae a bit with the tps to get a smoother ride and idling. Show many other performance tuner that will map a performance turbo car with tps and just use 16 map sites to compensate for boostpressure, 99% of systems that's setup to work that way is for NA and the 16 map sites is just to compensate for altitude. I guess that's why it takes so long to tune it, because to get the best out of it you have to tune it for you base TPS matix with like 0bar boost and then start by increasing boost and then just add the factor needed in the map site to increase the fuel needed but then that one factor is used for your whole TPS matrix, and that makes for a very linear setup , it'll work if your engine has a VE 0f 100% from idle to topend. But no engine works that way, so the factor will be set where the engine is at it's highest VE because that's whre it would've been the leanest, so where the engine is not at it's best VE it will run rich, not by much, but it will.


That's why I decided to go with the Microtech MT10S with the 4X ignitor box. There you can use just map or tps or a combo. I always tune with Map as by base setup and just compensate with the tps for normal driving.

Full racecars I don't even hook up the TPS.