Talkin' EA82T and IHI VF4's etc

steptoe · Post by **steptoe** » Thu Aug 04, 2011 5:05 pm

Disco in his days of research on turbos for his EA82T had a great link to IHI listings on turbos. I was wondering why VF4's are called such as they are cast VF with a serial No then beginning with a 4 so figure that is where VF4 came from. I have a VF with number then beginning with a 5, is it a VF5 or VF4 ran out of numbers?

Did an advanced search on Disco, IHI VF4 and got 20 pages !!

VF5 has a part No 14412AA003 whereas VF4s have 14412AA031 , 032

superceded?

FROG ,how do subes superceded numbers travel , next available number?

Now asking questions about these have found 4 plugger Vort ECU has an electronic control over the wastegate actuator and not direct like 3 pluggers, and the valve control sits on the front guard inside near the same thing that turns on boost light in dash.

Anyone got a Disco style explain of the unit? Can it be bypassed without consequences? Increase boost is not good idea but can t be done with this unit in place?

FROG · Post by **FROG** » Thu Aug 04, 2011 5:21 pm

steptoe wrote: VF5 has a part No 14412AA003 whereas VF4s have 14412AA031 , 032

superceded?

FROG ,how do subes superceded numbers travel , next available number?

yep generally a 14412AA031 would go to 032 033 then 034 etc etc there are exceptions to the rule though and any part can be superceeded numerous times and sometimes you might need say two bolts as well because a flange thickness has been altered

Gannon · Post by **Gannon** » Thu Aug 04, 2011 6:22 pm

Its an ECU boost control which uses the MAF voltage as feedback, I had it on my wagon, but I'm unsure of what difference it made because I didn't have the (I realise now, important) restrictor pill between the solenoid and the intake pipe. It works as a variable bleed valve, but without the restrictor, it bleed too much and had no effect on the boost.

It basically compared MAF voltage to RPM and if the MAF voltage was not high enough, (either because of low air density, blocked air filter etc.) it would increase the duty cycle of the solenoid to increase the boost to a level that is within the "happy range" of airflow that the ECU likes to see.

You can bypass it with no ill effects.

Basically it ensures the engine always produces the same power.

steptoe · Post by **steptoe** » Thu Aug 04, 2011 6:35 pm

aha, 031 on apr 87 make unit so 032 is later model turbo. VF5 would think it is younger again but find its 003 supercedes to 032 as well!

Thanks Gannon, so may be a smoother power delivery so long as MAF working and happy

steptoe · Post by **steptoe** » Thu Aug 04, 2011 6:42 pm

Aw, look VF48703 is on Vort from 8704 make date, VF58611 wonder if it was made Nov 86?
another VF4 8806 and another VF48811 - jun and nov 88? perhaps??

the VF5 003 of 11/86 supercede to 031 ? for short time then both 003 and 031 03/87 supercede to 032 ? uh huh!

so what is with VF5 ?

Google it eh?

discopotato03 · Post by **discopotato03** » Thu Aug 04, 2011 7:01 pm

steptoe wrote:Disco in his days of research on turbos for his EA82T had a great link to IHI listings on turbos. I was wondering why VF4's are called such as they are cast VF with a serial No then beginning with a 4 so figure that is where VF4 came from. I have a VF with number then beginning with a 5, is it a VF5 or VF4 ran out of numbers?

Did an advanced search on Disco, IHI VF4 and got 20 pages !!

VF5 has a part No 14412AA003 whereas VF4s have 14412AA031 , 032

superceded?

FROG ,how do subes superceded numbers travel , next available number?

Now asking questions about these have found 4 plugger Vort ECU has an electronic control over the wastegate actuator and not direct like 3 pluggers, and the valve control sits on the front guard inside near the same thing that turns on boost light in dash.

Anyone got a Disco style explain of the unit? Can it be bypassed without consequences? Increase boost is not good idea but can t be done with this unit in place?

I sensed a disturbance in the force but was unable to attend the cold wastes of cyber space .

Gawd it must have been a lifetime ago and most of what I searched for in these old VF series IHIs came from I think Ford or Mazda sites .
The killjoy was finding out that aside from the cartridges used in the VF2-8s you can't get spare parts for them so they are a bit of a dead end .
EA82T wise the only significant change was some rare European version had a R15 turbine housing rather than the usual R12 . The simple fix would be to use the one from a VF11 (USDM) or a VF10 .
I always thought it was a pity we didn't get that VF11 because its cartridge/wheels would have made great upgrades to EA82Ts .
Mild turbo upgrades tend to work best on them .

Now to the two pressure switches , I believe in the early 85/86 RX Turbos these are to one switch on the dash boost light and two tell the computer to shut the engine off in over boost situations ie the waste gates valve failed to open . Engine protect device in the form of a simple cheap diaphragm switch .

Now back to the dark side ...