Power FC gurus needed!

[Shaun]

GDay,

Im in the process of putting an R33 GTR engine (with a single GT3540 turbo) into my R32 gts-t.

I was going to use an Autronic SM4, however, after talking to knowledgable people, and in the interest of saving money im 98% sure ill go the Power FC.

The area of electronics and ECU's is my weakness, so please forgive any simple questions.

My questions relate to what type of PFC is needed to get my car up and running perfectly.

1. As i understand it, the PFC for the R32 gtst is extremely rare. Is this true?

2. Keeping in mind that my R32 loom only has provision for one AFM, can i use an R32 gtr PFC and somehow modify the loom to use 2 AFM's?

3. I have heard that people have used R33 gtst PFC's in R32 gtst's. Can this be done easily? If this is possible, ill just use a single Q45(?) 90mm AFM.

4. Does anyone know if you can buy a replacement loom from Apexi (as with Motec or Autronic). Because if this is possible, i could just get a gtr loom.

5. Does the PFC control air conditioning etc like the standard computer.

Sorry for all the questions. As you can see, my problems are associated with the different loom/engine combination. If there is anything i have missed, let me know. I want this car to be able to be driven daily without any problems on cold start etc, and i dont want to do any ground breaking with the Autronic.

Any assistance or comments/suggestions would be greatly appreciated.

Shaun.

[BHDave]

GDay,

Im in the process of putting an R33 GTR engine (with a single GT3540 turbo) into my R32 gts-t.  

I was going to use an Autronic SM4, however, after talking to knowledgable people, and in the interest of saving money im 98% sure ill go the Power FC.

The area of electronics and ECU's is my weakness, so please forgive any simple questions.  

My questions relate to what type of PFC is needed to get my car up and running perfectly.  

1. As i understand it, the PFC for the R32 gtst is extremely rare. Is this true?  

2. Keeping in mind that my R32 loom only has provision for one AFM, can i use an R32 gtr PFC and somehow modify the loom to use 2 AFM's?

3. I have heard that people have used R33 gtst PFC's in R32 gtst's. Can this be done easily? If this is possible, ill just use a single Q45(?) 90mm AFM.  

4. Does anyone know if you can buy a replacement loom from Apexi (as with Motec or Autronic). Because if this is possible, i could just get a gtr loom.

5. Does the PFC control air conditioning etc like the standard computer.

Sorry for all the questions. As you can see, my problems are associated with the different loom/engine combination. If there is anything i have missed, let me know. I want this car to be able to be driven daily without any problems on cold start etc, and i dont want to do any ground breaking with the Autronic.  

Any assistance or comments/suggestions would be greatly appreciated.

Shaun.

The type of PFC you run will come down to the loom you decide to run as there are generally (cant say definately as i haven't played with a GTR loom) differences in the ecu pinouts.

I personally would be looking to get ahold of an R32/33GTR loom, particulary if you still have all the gtr afm's, sensors and the like as it will make life alot easier when it comes to plugging in your PFC. I'd then use the corresponding PFC. If your lucky the 32GTR loom may even plug straight in.

I am running an rb25det in an r32 using r33 loom and pfc with no issues. And yes the AC and Power steering idle step up still works.

Have fun.

[Shaun]

Thanks Dave. Unfortunately i dont have the AFM's, so ill have to buy these. Im actually starting to think that using the PFC will cost as much as the Autronic i was originally going to use (when you factor in AFM's, Rewire etc). More research needed it think.

Shaun.

[Sydneykid]

Hi Shaun, I have already shared my thoughts with you directly, but for the other readers;

Based on what we have already done for our race R32GTST, that is getting the new RB31DET, I would use an R32GTST Power FC;

1. It will plug into your original R32GTST wiring harness. Zero rewiring costs.

2. Swap all of the sensors off your RB20DET

3. Use a single Q45 AFM ($300) (one turbo = one AFM), just select Q45 on the PFC AFM menu

4. The base maps and all of the sensor calibration will work with your combination

5. This means it will start and run on the default maps, you can start you own engine

6. Usually quite well enough to drive it gently to the tuner, this is the big advantage with a Power FC. That means zero installation costs

7. Costs ~$1,000 for the R32GTST PFC

8. You only have to buy a Commander ($400) if you want one, most tuners have them

9. You can borrow my Commander or my Datalogit for tuning if you want. YOU (not someone you have to pay by the hour) can check all the sensor calibration and fault find with the Commander.

10. That's another advantage of the Power FC, there are plenty around to borrow/learn from

11. The Power FC comes with very nice cold start, cold run, warm start, hot run, aircon, power steering and electrical load compensation. This take days to program into a Motec/Autronic and add considerably to the delays (before you can enjoy your car) and costs. Cold start and run tuning can take 3 or 4 days as you can only do it once per day, in the morning when the engine is totally cold.

12. The Power FC will handle HUGE injectors, we have used up to 1300 cc injectors and the engine runs perfectly and gets good economy (considering it power output).

13. As a result the tuning costs are minimised, around $400 is not unusual

14. Multiple throttle bodies and turbos are not good friends with MAP sensors, you get far superior airflow sense out of an AFM.

The bottom line, we use Motec, Autronic, Microtech and Electromotive ECU's (as well as Power FC) and I can guarantee you won't get anything that approaches the value for money and "nice" running that you will get out of a Power FC.

[Gav]

The PFC doesn't know/care what type of motor you have. It relies on the various sensors. The fact that you are staying with a single terb means that you only need a single AFM (which is what the R32 gts-t PFC would expect). All the other sensors should be transferable between the RB20 to the RB26.

The PFC for this model is available on special order and will take a little longer to arrive as well as being a bit more expensive. Personally I would think that it would be easiest to get the gts-t PFC rather than change looms and add the additional sensors (inc. a second AFM) that the GTR PFC would need. I would suggest that a Q45 afm would be needed if you go this route.

The Autronic solution is, of course, also viable although I suspect this will be more expensive. There are ECU loom adaptors available from Japan tha will save you cutting your existing loom.

Another option is to have the standard ecu reprogrammed.

The route you choose probably depends on how comfortable the workshop is with their and your preferred option.

Good luck!

[Gav]

Sorry SK - you replied whilst I was compiling my thoughts/post!

[Shaun]

Thanks very much guys. Your advice is appreciated, and i will certainly take it on board.

My concerns with the PFC route are:

1. The state of my loom. Ill have to check whether its salvagable after its was massacared by the addition of a microtech (dont ask!).

2. The addition of the Q45 AFM. If i remember correctly, this is 90mm in diameter. As the inlet of my turbo is about 102mm, ill have to fabricate a reducer (or similar) to accomodate the AFM.

3. My engine builder/wiring guy is familiar with the Autronics, and im concerned about finding someone else, as he already knows how anal i am with my car.

4. Thats all i can think of............... which is pretty good, as my concerns with the Autronic far outweigh those above.

More questions relating to AFM's:

1. Will the 90mm Q45 AFM create a restriction to air flow thats worth worrying about?

2. Does the AFM have to be mounted a certain way. Ie; Can i mount it horizontal, vertical, upside-down etc? I'd like to make a cold air feed, and the AFM creates a few hassles.

3. Is there another AFM available thats about 4 inches (102mm) in diameter that will suit the PFC? Just so i dont have to fabricate a reducer, as i wanted to make a sexy 4 inch stainless induction pipe from my turbo inlet to a pod within the guard.

Thanks for any help/ideas/suggestions.

Shaun.

[Shaun]

Hey, im pretty keen to know what peoples thoughts are about the Q45 AFM. Will it create a significant restriction to air flow, as its only 90mm and my turbo inlet is 100mm? My engine guy thinks that it would create a restriction, seeing as though im hopefully looking at around 350rwkw.

Does anyone know of a larger AFM that will suit the power FC?

I dont reckon it would create a huge restriction, as my exhaust is 94mm. If the AFM will restrict air flow, so too will the exhaust, and i dont think that will happen. Anyway, im keen to hear your thoughts.

Thanks,

Shaun.

[paulr33]

Rule of thumb for Air Flow meters RWKW & Engine BHP

------ ---- OD ---- RWKW ---- RWKW ---- BHP ------ BHP

No of AFM's ---- ------- 1 -------- 2 -------- 1 -------- 2

RB26 ------ 65 ------ 149 ------ 299 ------ 271 ------ 474

RB20/25 --- 80 ------ 226 ------ 453 ------ 376 ------ 683

Z32 ------- 80 ------ 255 ------ 511 ------ 415 ------ 763

Q45 ------- 90 ------ 302 ------ 605 ------ 479 ------ 890

the q45 shouldnt pose a restriction at 350rwkw

[Shaun]

Thanks for your input, but im not sure i understand. Ill be using 1 Q45 AFM, and your table says it'll handle only 302rwkw. Im aiming for around 350rwkw, but you say it shouldnt pose a problem.

Also, does anyone know if its possible to place the AFM on the pressurised side of the turbo. Ie; before or after the intercooler. I'd say it'd have to be after the cooler due to the extra heat generated by the pressurised air.

Thanks,

Shaun.

[FATGTS-R]

Hi Shaun,

I have an Autronic SMC (RB20) and just thought I would throw in my 2 cents. To be blunt its been a nightmare. The car has been back to the shop ( its there now ) so many times I cant count. But this could be tuner related and also I have changed a few things along with the fact the car is from 1987 so take it with a grain of salt and not an attack on the product as research will show it has a great track record.

In saying that one unit was found to be faulty after a month or so which cost the workshop considerable money and labour chasing a gremlin that was a dud unit which cost him three weeks of labour and wages, 300 litres of fuel and over 40 sets of plugs.

I guess I'm biased now because of my troubles but if I could have the decision again I would have chosen a PFC.

I got a great price on the unit and install but got caught up in the hype of having an Autronic ecu thinking nothing can go wrong but didnt ever think about all the little things that end up as being big things i.e cold start, hot start, electrical load compensation etc which as SK mentioned can take days which end up as weeks and months if if you want a great result.

As an example my cold start alone was a fortnight before the tuner was happy to give the car back to me but I must say its like factory now.

I guess what Im trying to say is that the Autronic although being a high end ecu requires patience to get right and make the most out of it whereas the PFC although not having all the functions has a great head start being model specific and having a lot of things pre loaded into it like the cold start etc.

You never realise how great a cold start mode is untill you have to crank for 10 seconds to fire up and then sit there for ten minutes blipping the throttle before you can drive off without stalling.

Just need to remember that the factory ecu programming would of had an army of technicians with a mega budget and years to get right. Dont think XYZ workshop can come even close to emulating this in a few hours on a dyno.

Sorry to rant but good luck on whatever decision you make.

Jayson.

[Shaun]

Thanks Jayson, thats exactly what im afraid of! Also, in my case, ive got the MAP sensor and multiple throttle bodies problem to overcome.

Apparently the Autronics now come with the 'Self Tune" (i think thats what its called) program. Did yours have that? Also, did you use the CDI Ingnition Module with the SMC?

Thanks,

Shaun.

[paulr33]

hey shaun,

sorry what i meant was i dont think the size of the airflow meter will pose a restriction. the afm and power chart is an estimation, you may actually find that once you use it you may get to 4.5v at max of the q45. its hard to say, but that is an estimate. well the next power break above a single q45 is twin rb25 afms which can be had cheaply so maybe that as a "failsafe" option, estimate to max out at 450kw based on that table

[Sydneykid]

Rule of thumb for Air Flow meters RWKW & Engine BHP

------ ---- OD ---- RWKW ---- RWKW ---- BHP ------ BHP

No of AFM's ---- ------- 1 -------- 2 -------- 1 -------- 2

RB26 ------ 65 ------ 149 ------ 299 ------ 271 ------ 474

RB20/25 --- 80 ------ 226 ------ 453 ------ 376 ------ 683

Z32 ------- 80 ------ 255 ------ 511 ------ 415 ------ 763

Q45 ------- 90 ------ 302 ------ 605 ------ 479 ------ 890

the q45 shouldnt pose a restriction at 350rwkw

That is one of my old tables (about 2 years old I think), we have now reached 420+rwkw with a single Q45.

Hey, im pretty keen to know what peoples thoughts are about the Q45 AFM. Will it create a significant restriction to air flow, as its only 90mm and my turbo inlet is 100mm? My engine guy thinks that it would create a restriction, seeing as though im hopefully looking at around 350rwkw.

Does anyone know of a larger AFM that will suit the power FC?

Is the 100 mm the OD of the compressor inlet or the ID? The true comparison is the ID not the OD. The turbo on ther R32GTST has a 100 mm OD compressor inlet but only an 84 mm ID. Hence the90mm Q45 is a pretty good fit.

I have seen a Q45 hot wire installed in aluminium pipework. It was 100 OD, but the tuning for off idle response was a bit tricky.

I dont reckon it would create a huge restriction, as my exhaust is 94mm. If the AFM will restrict air flow, so too will the exhaust, and i dont think that will happen. Anyway, im keen to hear your thoughts.

Thanks,

Shaun.

Inlet restriction (before the turbo) can not really be compared with an exhaust restriction. The exhaust restriction has a double effect, firstly it limits the egress of the exhaust (obviously). To that is added the limitation of the air into the engine. This manifests itself as higher boost, needed to overcome the exhaust restriction.

Thanks for your input, but im not sure i understand. Ill be using 1 Q45 AFM, and your table says it'll handle only 302rwkw. Im aiming for around 350rwkw, but you say it shouldnt pose a problem.

Nom, as per above.

Also, does anyone know if its possible to place the AFM on the pressurised side of the turbo. Ie; before or after the intercooler. I'd say it'd have to be after the cooler due to the extra heat generated by the pressurised air.

Thanks,

Shaun.

Yes, do a search we have discussed this option a number of times. I have even seen a car with it done. It is usefull if the turbo has a large amount of reversion that can cause problems with the AFM measuring the airflow twice. Once on the way and once on the way out. This results in very rich running at low rpms, stalling, rough idle etc.

Hope thet above was of some help:cheers:

[Shaun]

Im such an idiot SK; yes the OD is 100mm!

420rwkw on a single Q45 certainly places my doubts to rest about restriction to airflow! What car was this on? A single turboed RB26, or is that your RB31 GTST?

Thanks,

Shaun.

[Sydneykid]

Im such an idiot SK; yes the OD is 100mm!

420rwkw on a single Q45 certainly places my doubts to rest about restriction to airflow! What car was this on? A single turboed RB26, or is that your RB31 GTST?

Thanks,  

Shaun.

A sister engine to the RB31DET going into the R32GTST.