2jz bmw 525i

[Xulfiqar]

the air cannot reverse flow as air has mass and acts like a train wreck when it meets a wall (throttle), it sort of piles up on itself. At this point the turbo is already forcing a ton of air volume - the BOV will open up and this will cause the BOV to open faster (higher pressure at hot side) and let out the hot and low density medium (air) as its flow velocity is quite higher than the train wreck happening after the cooler (increased pressure at the train wreck site too causing a clog in the system)

as long as the BOV is open the turbo is allowed to keep spinning and dump the hot air. (This is good - we can then mash the go pedal and our turbo will keep up - and we get faster response time)

Doing this on the cold side causes this air (train wreck which we actually spent energy on to cool down) to escape - we also know that there is a pressure drop across the cooler - which will suddenly cause backup at the hot side (clogged toilet situation) when the throttle closes and the air charge tries to compress - so you tell me yourself - which situation will cause turbo surge.

This compression happening in the charge pipes will also cause heating up of the charge air. (albeit minimal but nonetheless its present and it hurts your goal)

you may notice that the factory blowoff valve on an RX7 is on the hot side of the cooler.

[Mintralevel]

To be very honest, i just watched the pic on the net and got it installed on the cold side, thinking that the reverse flow should not enter the inter-cooler again, but guys, seriously, i am learning a lot, and that should be fruitful once inshallah i fine tune it, as per now got hold of the stock turbos, and khan bhai is asking 35 k, i have offered 20 k, lets cee, where it ends up

[Xulfiqar]

one miscalculated act on a turbo engine = gone engine

[azkhan]

@mintralevel

Following are the solutions to your problems as per my experience of swapping a 1jzgte vvti coupled to original a340e in a w124 (MA without check engine light and almost all gauges working) and tuning it:
1. Speedometer
What is your gear model is it w58 or r154? Moreover, is your speedometer cable or pulse operated.
If cable you can find a vss sensor with a cable output.
If you have a pulse operated speedometer you have to tap the vss sensor data and feed it to a universal electronic speedometer which could be simply calibrated to get the exact speedo reading. Later on you would have to modify your speedometer cluster to fit that universal speedo. Universal speedo is something like DEPO SPEEDOMETER - Upgrade Motor Sports
(Bought mine from jz@pakwheels at a much cheaper price but its accurate)

2. Coolant Temperature
Here you have two options:
1. Try to make an adapter of bmw original temperature sender for 2jzgte coolant sender and fit the original bimmer sender and you'll get accurate temperature reading.
2. Get hold of a good ohmmeter and take your original sender and 2jzgte sender to a shop holding a variety of temp senders (like diamond electrical shop in gawalmandi) now match the threads of 2jzgte's sender with available senders at the shop. Now measure the resistance of bmw sender.
Now check the resistance of filtered senders with matching threads and get one with resistance closest to bimmer sender and get that installed.
To compare the sensors readings connect an obd2 scanner and temperature readings on the gauge and remember the difference. In this way you would get quite accurate idea of temperature.

3. Fuel Gauge
Dont have any idea but there is no connection of engine swap and fuel level gauge but vague reading might be due to loose engine/body grounding.

4. BOV
Since you have 2jzgte VVTI (seems from your cam) you must be having AFM instead of MAP, which requires a plumb back BOV instead of a BOV which would just release in atmosphere. Therefore, I would recommend you to either use factory BOV by turning it to or get a plumb back BOV to tune your car properly. Moreover, i agree with the logic of Xulfiqar and OEM BOV's on jzgte's are on hotter side very close to turbo.

If there is problem with wiring to BOV there is a solution on internet (not tested by me)
Blow Off Valve's on the VVT-i - Page 5 - FAQs & Sticky Threads - JZX World Forums - Page 5

Hope this helps. Regards.

[Mintralevel]

Dear Bro azkhan, thx for a detailed write up, i have

1. W-154 Transmission
2. Speedo is pulse operated, all electrical, was thinking of putting in a Lexus or Aristo cluster
3. Coolent Temp, i am really sh..t scared...., not even had a clue, thanks for the guidance
4. Fuel Guage : Was a old problem, before putting in JZ
5. I have no clue wat a plumb back BOV is
6. As per Bro Xulfi's advice, new angles are being fabricated and hence a new BOV will go closer to the turbo (hot side), the only problem is with reduced angles of the piping intercooler is really going close to the ground, so guess i am up for a new suspension setup

You all take care of your self and keep guiding, at the end of this i owe you a big dinner at "Minaal" i guess?????

[azkhan]

@mintralevel

Pm'ed you my cell number get in touch whenever you need help sir. Its always a pleasure to help a fellow enthusiast.

[Mintralevel]

So true sir, this turbo thing is really a pain in the butt

[rajaatta]

So true sir, this turbo thing is really a pain in the butt

you can easily get the gauges perfectly fuel, temp, speed , tacho, by altering the other gauges in it the front face of gauges and the needle's will remain same so in the bmw you will had toyota setup and all thing's will be fine if you need more info feel free to contact me.

[Mintralevel]

Raja saab kindly send my your number, i will be in touch with you

[rajaatta]

Raja saab kindly send my your number, i will be in touch with you

my cell is 0311-4451670

[bravo122]

@
Speedo and the fuel gauge wont be a problem.Since you already know of stubble go there and ask for speedo meter repair guy.There is a Shop who just does this stuff.i.e repair gauges/alter gauges his rates are prety reasonable compared to others and is an expert at this.
Show your car to him
If i am not wrong he is just beside the turbo wali shop

[Mintralevel]

Finally after lots of money, sweat, tears and pain