R33 Auto + Pfc Faq's

[dangerman4]

I have a S1 r33 auto which is running a built rb25 and a power fc.

The car made over 200 kws for about 3 months then up to 270kws for 6 months and now its up into the 300 -340 kw range. Over this time i have posted several times of the benifits of running a pfc with the auto on a S1 r33 and each time i have been laughed at and shut down by numerous members and moderators on here that drive manuals.

now im a bit confused as to why everyone comments that it wont work or will cause terminal damage to you trans in a matter of weeks, yet they have no proof of this ever happening. My car has been running a shift kit since not long after i imported the car, which totally relieves the need for the ecu to retard timing, as the shifts are clean and precise and happen in .5 second. My car has been serviced by Mike at MV automatics thruought its life in Australia, and he has never found a difference between autos with stock ecu or after market ecu once a shift kit is installed.

On thursday i dropped my car off to mike for a full trans kit including high stall, kevlar clutches etc.

he has since stripped my trans totally and cant find any flaws.

So after 18 months of daily abuse all the bands etc are still happy!

So if the No1 import trans builder in australia cant find a problem with running a PFC on a S1 R33 auto, then how can all the know it alls on here think otherwise.

"Sydney kid" Gary has stated he has been in several autos running aftermarket management and the PFC was the best of them, but i dont think any of them had a shift kit installed. I believe if he was to drive my car himself, and then describe his findings on here everone may have a very different opinion of the whole PFC auto debate.

also

A couple of months ago i also tried helping people by letting them know how to lock there car in drive to tune on a dyno, but no one seemed interested.

seeing as there is a hell of a lot of auto r33's out there i figured that evryone would want to know how to stop there cars kicking back to second on the dyno, as this can result in over reving, wheelspin, or broken straps and a bent car, let a lone if someone was standing in front of the car.

i just think the auto ecu FAQ thread in " FI " is very misleading, and should be edited accordingly.

Let me know your thoughts

cheers Darren

[Tangles]

Good work Darren, Im glad to hear that Mike has confirmed that the internals of the box were still in great nick. The drive on Monday showed me that the shifts, with a shift kit + Pfc, were absolutely fine. There is definately a fair bit of Miss Information out there in regards to autos / Pfc / shiftkit combo's.

In fact, after that little drive, Ive started looking for a Pfc, lol. Dont have the ca$h for one, but the homeloan wouldnt mind, Im sure Would like to take you up on that valve body offer too........

Brendan

[dangerman4]

Good work Darren, Im glad to hear that Mike has confirmed that the internals of the box were still in great nick. The drive on Monday showed me that the shifts, with a shift kit + Pfc, were absolutely fine. There is definately a fair bit of Miss Information out there in regards to autos / Pfc / shiftkit combo's.

In fact, after that little drive, Ive started looking for a Pfc, lol. Dont have the ca$h for one, but the homeloan wouldnt mind, Im sure Would like to take you up on that valve body offer too........

Brendan

Hi Brendan

ive spoken to mike and he is going to reuse the one allready in the car so if your keen to get your self some trans fluid and a gasket then the shift kit has your name on it.

cheers

[Sydneykid]

Darren and I have had this communication several times. But let me clarify for other readers.

I haven't driven Daren's car, next time I am were he is, I will (if he lets me of course). I have no doubt that Darren thinks his car drives perfectly OK, that's his opinion and he may well be right.

But (there is always a but) I have driven 5 other Skylines whose owners made exactly the same claim and the cars all drove terribly IMHO. The upshifts were harsh at full throttle and annoyingly jerky at partial throttle. The shift from reverse to first while moving was a head bouncer. Driving slowly around car parks or in traffic was a lesson in preparatory neck bracing, brace yourself there’s a gear change coming. The common kick down from 3rd to 2nd was particularly annoying. The way I look at is, if I have to drive an auto, at least it should be smooth.

When I last checked 2 of those 5 Skylines had had gearbox rebuilds and 1 of the remaining 3 has reverted back to the standard ECU.

I honestly don’t think Nissan would have gone to the considerable trouble (and expense) to write all that programming code if they thought that ignition cut and/or retard on gearshifts wasn’t necessary. Since all other vehicle manufacturers do something similar (not always via the ECU) Nissan are obviously not alone in that thought process.

I have no doubt that Mike’s upgrades would make the gearbox last longer, the mods are logical, well thought out and executed. None of the upgrades would be considered unusual in terms of any automatic, including the drag racing specialists like Race Glides etc. What Mike brings to the table is the expertise in import autos and then he applies the well proven techniques to get them to live. The $300 or so valve body upgrade is particularly good value for money. After that it starts to get less so, band and clutch upgrades for a 4 speed auto are not inexpensive.

But, each and every one of those upgrades adds a level of harshness to the gear changes. That’s how they function, by shortening the amount of time taken for the change and making that change itself a more solid engagement. When you add that to the harshness caused by the lack of ECU shift programming, you end up with a compromise on shift quality that I personally find very unappealing.

Horses for courses, some people may like it like that, I just happen not to.

Cheers

[dangerman4]

Hi Gary

did any of the autos you have driven have a mv shift kit in them?

As with my car there is certainly no violent changes either up or down.

wheres SuperCubes when i need him?

he can vouch for the shifts as Tangles has mentioned above.

Or should i just give up and keep my findings to myself.

[WazR32GTSt]

thanks for the info, mate

as an auto driver, although i might never get a powerFC i appreciate your testing and posting the results you find, it does help the commuinity as a whole

[Abo Bob]

I think there is one important fact missing from this thread. You want power? Well guess what, it comes with an increase in the harshness of the ride.

Proof is in the clutch that can handle 300rwkw in a manual. We are not talking about a smooth stock like thing here.

Of course the changes are harsh at high revs. They are supposed to be. You can't slip and slide into the next gear when running this sort of power. This is also how you go fast. Change gears as quickly as possible.

The concept of a shopping trolley with over 300rwkw is not realistic.

I honestly don’t think Nissan would have gone to the considerable trouble (and expense) to write all that programming code if they thought that ignition cut and/or retard on gearshifts wasn’t necessary. Since all other vehicle manufacturers do something similar (not always via the ECU) Nissan are obviously not alone in that thought process.

It was necessary so they could run a shopping trolley style auto. That style can't handle massive power. With the upgrade to the VB you don't need it at all.

If you are at light throttle there is no inertia to snap your neck. You might hear it banging away a bit but you also get that with mechanical diffs and bitey clutches sometimes.

[Turbo1958]

hey mate good on ya for sticking up for your self .. I have a R33 Auto as well and i am running a Microtech LT12 piggy backed .. i still have my stock ecu to run auto ecu and the LT12 just runs the engine side of it and i have had no probs with my auto ..

Edited December 8, 2006 by Turbo1958

[GTRgeoff]

Ultimately it all comes down to personal likes and dislikes. What Darren, Gary and Adam have stated is all too true from an individuals perspective.

Unlike most others I have both manual and auto R33's, in fact the whole turbo collection and if I wasn't pouring money down the drain on big turbos for the GTR and twin turbo/GTR throttle setups for the GTS25t I just know I'd be putting the PFC in the auto for some fun and experimentation.

In the world of Engineering and Science all things that are known remain true....until someone comes along with a different answer and then proves it. So to that end I say to Darren, start an alternative FAQ with your experiences detailing what you have done including how your car is tuned and how you drive your car to with the changes, because if you have done it then it is a known truth and an alternative for the auto owners. Gary offers some insight into what can go wrong, but you offer what can go right and with performance modifications you have to be willing to accept a serving of each before you are done, as well as make some allowances for the changes if you have any mechanical sympathy whatsoever.

Personally I find the 25t auto just damn annoying in that it seems too sluggish for what is really suppposed to be a sports car. The Soarer V8 is more responsive and shifts better so if I were intending to keep the auto I'd be doing something, but 350GT CVT8 is calling.

I'll be looking forward to the new FAQ.

[discopotato03]

An interesting read from the sidelines for those like myself who don't go with automatics but are interested in problems and solutions .

One above did mention the issues with power/torque increases and living with at times a higher state of engine tune ie power range moved up rpm wise . In my inexperienced opinion getting the transmission to stand up to the changes with lots more torque and revs will be quite a challenge and if the ask is a smooth change someones really got their work cut out for them . Far from impossible but need articulate minds and probaby lots of time and financial resources .

The future seems to be (as mentioned) Continuously Variable Transmissions which have gone far beyond econobox class cars (Micra ?) to Z's and even into the heavy transport arena . They help solve problems with earlier automatics but rely very heavily on electronic brains to make it happen .

OT I know but I'll stay with manual because it changes when I tell it and is divorced from the engine control systems . I think at times it valuable to know whats about to take place rather that hope the electronics act predictably because sometimes they don't .

We shall see , cheers A .

[paulr33]

im happy to add a section on the PFC faq for auto stuff

but if some guy reads it, blows up his auto box then i dont wanna be responsible!

[GTRgeoff]

Why would you be responsible Paul? Each time one of us increases power etc we are responsible to ourselves for the flow down effects. Dodgy workshop work notwithstanding.

Are those of us who recommended to others to come to the race track responsible if they have an accident?

All we can do is provide sufficient info for others to make an educated decision, rather than keep it to ourselves.

[rd-runr]

Why would you be responsible Paul? Each time one of us increases power etc we are responsible to ourselves for the flow down effects. Dodgy workshop work notwithstanding.

Are those of us who recommended to others to come to the race track responsible if they have an accident?

All we can do is provide sufficient info for others to make an educated decision, rather than keep it to ourselves.

That's right.

I have an R33 series 1 auto with an MV shift kit/TB upgrade. I've found the harshness in gearchanges to be from 1st to 2nd. I've got emanage running piggyback, the PFC working with shiftkitted autos makes sense.

[SoFreshSoClean]

I have a bog stock, auto 4-door and I find the chang from first to second to be harsh, so it might just be a Skyline auto thing?

[rob82]

There is going to be a point at which the standard ECU cannot control the harshness of a shift due to the fact that the nissan ECU only has control of igntion as a torque reduction methodology. The more you retard an ignition event the more like you are to burn exhasut valves, destroy catalytic converters and spool the turbo due to the combustion event being very late in the cycle. Too much retard is only going to add torque as its spooling the turbo.

The one benefit is that usually with skylines to make more power you generally need a larger turbo/'s which shifts the power band up in the rev range. This means that the line pressures should be higher to avoid too much slip on the shift. However if you are making more power at the same rpm and throttle angle below say 3500rpm you may need to bump line pressures up mechanically or electronically (If possible). Manufacturers reduce line pressures at low rpm and throttle angle for economy reasons.

At the end of the day if you have an auto skyline making reasonable power IMO not even the standard ecu remapped will be able to cope with the added power in prolonging the trans so you may as well get an auto build.

Also get your tuner to take considerably notice of the ignition timing at various shift points as auto's can add considerable torque to the engine on shifts.

Edited December 9, 2006 by rob82

[4door_Sleeper]

As the first person to have a PFC and the shift kit in an auto 33 (I think I was first on the forums) I have not been disapointed.

My auto is still fine, and whilst the gear changes under full throttle are more harsh, the feedback I have had from others with big KW manuals, is that their shifts can be harsh (or you stall).

The auto also shifts whilst still on boost and with the benifits of the torque converter you are still in the power band after the change (unlike a manual)

Hope this helps.

Edited December 9, 2006 by 4door_Sleeper

[skidkid]

dm4, Is that a valvebody/ shift kit up for grabs you have?

[Adriano]

Has anyone tried to fool the pfc into retarding the timing during gearchanges, by maybe latching a signal down(eg engine temp to 120 deg during gearchange)then just set that cell to say -10 deg? Would only take some simple circuitry, as long as it didn't register as a faolt code because of the sudden change. is there any tricks thet you could use with datalogit, im sure there will be a way to do this. On the consault can you see how much timing the standard computer pulls out on changes?

[paulr33]

the auto pfc does look ace i must admit

lots of auto logic control which u can set/change

[dangerman4]

the auto pfc does look ace i must admit

lots of auto logic control which u can set/change

auto pfc ?????