Fully adjustable ECU

Fully adjustable ECU's or better yet an aftermarket engine manegement system. Does anybody on here have one? Whats out there that would work with an inline 6 motor? I know theres lots of systems out there for the Japonese imports and they really allow you to make some power. I know a guy who tuned 50hp out of his turbo Miata by playing with the timing and fuel curves.

If this was put on a XJ 4.0L how much power could be achieved by tuning if the 4.0L has all bolt ons like intake and exhaust and such.

Thanks,

AARON

No one that I know of makes one for an xj. you have to consider that your friends turbo miata is a completely difrent animal.
There are amny bolt on tricks for the 4.0 and then when when the computer starts to not what your doing there are way that some simpily the bedt guys here on have come up. If the the trad below dosent help just as again thats why we are here.

I know that a miata is different from an XJ but what I mean is the preformance gains he sees from a tunable engine manegement can also be seen on a XJ. I know that there is no XJ Specific engine controler but why couldnt a controler made for a Skyline work? They are stright sixes right? I know there has to be all sorts of power gains especially with the torque if the fuel and timing are played with. Theres 4.0L of displacement begging to be unleashed. I want to at least try. This will be very expensive but the possibilities are almost endless.

AARON

What I mwant by it beein a diffrent animal is that those computers are controling turbo bost, tiimeing and fuel curves. The gains they are seeing are by fine tunning all of those to work together. The 4.0 is old school it dosent have a turbo, or variable valve timing and such so theres nothing much to play with. hey do make chips fpr the 4.0 that some people are happy with bu they are only worth 10 to 15 hp I think.
ntilll you add a turbo and a new egien managment system those wonder fulllittle computer aren't going to help one bit.

REDXJ4FUN said:

ntilll you add a turbo and a new egien managment system those wonder fulllittle computer aren't going to help one bit.

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Thats why I am asking now. I have some money that I want to use to start building a turbo 4.0L. The turbo is far off until I have all research done as well as all the funds set aside for it.

As for the Chips, theres no way in hell they get 10-15hp. Maybe if it was an ASE chip but not the Jet. I have been looking at these too.

Thanks,

AARON

For all the bolt-on performance mods, ported head, performance cam, and even a stroker, the stock PCM can adapt itself pretty well to these changes.
If you want more fuel you can get that either with larger injectors, an adjustable fuel pressure regulator (increase fuel pressure), or a MAP adjuster (increase injector duty cycle).
If you want more timing, you have to get a chip. The 4.0 doesn't need a lot of timing to produce full power (maximum advance 34 degrees) so it's doubtful that adding timing will help.
If you add forced induction you certainly need a custom engine management system. It can either be stand alone (managing all engine functions) or a piggyback system (manages only fuel and timing). The latter would be a more practical choice. One of the best on the market is the Perfect Power SMT-6 but it isn't cheap:

http://www.perfectpower.com/products/smt6.asp

Unfortunately it doesn't specify whether you'd need a 3-bar MAP sensor to monitor boost pressure (rather than vacuum).

The principal problem you will run into with XJ mods is that the aftermarket is not as well developed as it is for the "sport compact" (import trash" or "Big Three" automakers. If your XJ is OBD-I (1991-1995) or OBD-II (1996-2001) you will have more options than Renix guys like me (1987-1990.) Most of what you will concern yourself with will be increasing airflow in and out of the engine - both volume and efficiency. The 4.0 runs with a Volumetric Efficiency rate somewhere in the 70-78& range (from sims - I haven't had one on a dyno yet,) so incerasing VE is a step in the right direction. VE refers to how well the engine actually moves air vice what it can do in theory - most street vehicles run within a few points on 85%.

Dr. Dyno reports some very good results with head porting work, and for the typical environs of the XJ a stroker is well thought of (and Dr. D lists several variations on his website, which I am sure he will be happy to give you the addy for - since I can never seem to remember it and just click on a bookmark...)

Other ideas - discussion, and pros/cons - can be found on the "strokers" discussion board at groups.yahoo.com/group/strokers. We were even batting around a redesign of the 4.0 head there a while ago, which is a lapsed project that I need to resurrect if I can find someone with a marginal interest in production runs. Indy Cylinder Heads didn't seem to want to bother - I'm wondering about Clifford or perhaps Edelbrock?

Anyhow, you will likely want to start with Dino's site (I checked the "WWW" button under his post - it looks to work) and the Strokers group for your starting points.

You will also find that there isn't much in the way of electronic support out there for most (if not all!) variations of the 4.0 inline six, and that mainly has to do with everyone being more interested in B3 V8's and imported lawnmower engines. The nice thing about that is it gives a chance to show your creativity - provided you don't live here in California with all the Smog Nazis at CARB! All of my ideas won't see prototyping until I get out of here, and I don't want to hand proto work off to anyone else...

5-90

Yeah I've certainly had to be creative when it comes to performance mods and particularly the electronic ones. The mods to the electronics have basically involved modifying the outputs from various sensors to the engine computer. I have the JET Stage 2 PCM but that didn't do much. I can list my homebrew mods as follows:

Homebrew Powerstack FIPK
62mm bored TB
Ported head
Relocated IAT sensor (back in stock position after I installed 24lb injectors)
Coolant temp. sensor 4Kohm parallel resistor mod

Despite increasing the airflow through my engine and improving volumetric efficiency (up from 76% stock to 84% now), my engine still runs rich with the 24lb injectors so I've had to get creative again. How?
I built myself a homebrew MAP adjuster to lower the MAP sensor input voltage (and therefore output voltage to the computer) to reduce the injector duty cycle. I'll do a write up in the next few days and post details in this forum.

SO tell me - are there emissions regs in Riyadh yet? How about Cyprus? Just wondering...

5-90

In Cyprus, the emissions regs have been tightened up in line with the European Union and all vehicles from three years old and above must undergo an annual inspection including a sniffer test.
In Saudi Arabia, things are a lot more lax. They did introduce unleaded fuel two years ago and all new cars are sold with catalytic converters. Like Cyprus and the EU, vehicles aged three years and above are supposed to undergo annual inspections and a sniffer test but since you need to renew your registration document every three years, most people don't bother with annual inspections and only do the inspection when the registration renewal is imminent. The traffic police don't bother checking if the annual inspection's been done. As long as you have a valid registration document they don't care.
The sniffer test is as tight as the EU's but the rest of the vehicle inspection process is a bit of a joke. You can have broken shocks, sloppy steering and still pass the vehicle inspection, but you can be failed because the back up light for the rear licence plate isn't working.

Tell me more about the EU Smog Nazi regs, if you can. Somehow I get the feeling it's something that originated in Germany, and I remember doing maneuvers there (with the German, the driver, and the "Checkbook Man" in a MUTT at the rear... Damn that killed unit budgets!)

5-90

MrShoeBoy,

Hey, i saw that u were interested in building a turbo 4.0. I know far from everything, but I don't think that a turbo would be the best choice. Turbos are awesome, and the torque they can produce is incredible, but they are better suited to some engines than others. An unmodified 4.0L has a redline around 5200 RPM. A nice, efficient turbo probably won't even kick in till about 2.5 or 3 grand. Half your tach's power curve goes out the window. A supercharger kicks in imediatley, and although it doesn't produce as much peak power, it produces it for twice as long. I don't know your intentions for your XJ, but either street driving or especially off-road, this would probably work better. Also, because it is continous power instead of a surge, it is easier on the engine and drivetrain. A blower is most likely going to be cheaper as well, because its less complex. Again, not hating on turbos, but prolly not the best choice available for our engines. Just my humble opinion. Either will be awesome, so good luck with whatever u do.

I just reread this, and I'm going to agree with JeepSpeed on this - you're better off iwth a decent supercharger than any turbo. You will find there to be less plumbing, and turbos can be hard on oil since they continue spinning after the engine is shut off (gotta wait for the turbine to spin down, while a blower stops when the belt stops.)

You also don't have to redo your entire exhaust for a supercharger - while for a turbo, you have to rerun the exhaust setup to pass thru the turbo and setup the intake to give the turbo suction and exhaust into the intake. You can get a bolt-up surpercharger kit - including intake &/or adapters - from three or four different vendors already...

5-90

Actually a turbo would be the optimum set-up for performance. If you select a small enough turbo e.g. Garrett TO3, it'll start boosting from only 1500rpm and you'll have maximum boost by 2000rpm. Use an intercooler to reduce intake charge temps. and you can add more boost safely.
No supercharger on the market comes close to the efficiency of a turbo. A turbo is also easier to package under the hood and there are no belts to break.

Once again Dyno is dead on again turbos can be built to make a supercharger look stupid. If Mrshe has the time and realy wants to he can build a turbo for very little money that can be bad as heck. I had planed on doing a turbo MY streeet race but right now time just does make it possible. 450 to 500 hp out of a 4.0 is easy and it will live if you keep the rpms down under about 5500 and that uo to 15 pounds of boost. now there some thing you'd have to do to help the motor but it been done before. the most expensive thing aboutthe set up would be the computer but if it was a renix it does a very good job to a point of wworking with turbo.

Guess I'm just too hooked on Roots blowers - played iwth too much as a kid. If anyone does the turbo mod, I'd be interested in seeing a writeup!

5-90

Actually, I / we are currently building a twin turbo 4.0L (yes in an XJ) I general terms though, Turbos are extremely efficient if set up properly. A turbo can be configured with the right knowledge and setup on just about any engine. The key in turbo setup, lies in proper choice of turbo. More accurately, the proper choice of turbine to achieve boost at a specified rpm for your application. So even though a stock 4.0 revs to 5200, boost can be harvested though much of the rev-range.
Also, 4.0's can be fairly easy to super / turbo charge due to low compression from the factory. Sub 9.0 A stock 4.0 can have a turbo / super thrown on and produce 7 psi without detonation or issues supplemental fuel computers, alcohol/water injection ect.
Superchargers on the other hand are a great choice for their simple setup and cooler operation for the most part.

Well if you are realy wanting a fully addjustable system heres one but it will be some work to put in and get working.

http://www.034efi.com/034ECUSTGII.html

Thanks guys for the replies. I offroad my Jeep so the majority of the time on the trail 3000rpm wont be seen, but I also do most of my driving on the street and want more power there too. Can you say I want my cake and eat it too

XJ-ARMOR where are you located at? I would like to see this TT setup. What you said as well as Dr. Dyno said is exactly what a friend of mine said about my motor: If you match up the turbo for the displacement and RPM range of the motor you can achieve lots of usable power with in the RPM band.

JeepSpeed I dont want a supercharger for that exact reason. They are simple and are readily available from lots of companies. I am trying to go for unique and a custom turbo setup is exactly that. I understand about the surge of power so I have upgraded most of my drivetrain to handle the added power. The rear ford 8.8 is used in Mustangs and I have seen them push massive ammounts of power through that axle with out any problems. As for the front, people run stock motors, 760x u joints, with 35s no problems and I dont ever plan on going above a 33" tire. I also happen to drive like Mrs daisy off road too, fixing driveline stuff in the mud is bad:nono: When I find I start breaking stuff, then I will upgrade accordingly.

As for the ECU, any other contenders out there? I have looked at the SMT6 which is very nice, the unit that REDXJ4FUN would take lots of work but its going to take lots of work anyways, what about an Apexi Super AFC? I know that these are running rampent through the rice crowd. Any other opinions.

Thanks again,

AARON

MrShoeBoy said:

As for the ECU, any other contenders out there? I have looked at the SMT6 which is very nice, the unit that REDXJ4FUN would take lots of work but its going to take lots of work anyways, what about an Apexi Super AFC? I know that these are running rampent through the rice crowd. Any other opinions.

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Why don't you go over to a Honda lovers forum and ask for help?