911 3.2 Conversion ?

[Dieter9]

Hi there,

I am debating to go turbo on my 3.2 US spec engine.
I have read alot of topics, but they are all old.
I'm sorry for my english, i am from Europe.

What i am thinking of doing :

Turbo 0.63 AR GT3582 Pulsar
make own piping from manifold to turbo (intake)
oil feed from oil pressure checker
oil drain in drain plug engin oil
air filter under the car at the turbo ( universal)
wastegate with 0.5bar (7psi) spring
since turbo's have moved on... no bov is needed at this boost level.

Still not sure about these :

Use Jpipe or make my own starting from the Catalistic converter.
use a rising fuel pressure regulator + protomotive chip, or use full VEMS ecu and ditch the AFM all together, the VEMS could adjust fuel pressure at boost.
what is your idea about this ?

i would highly appreciate all inputs from you guys !

thx !!

PS: my car is "@85_9_1_1_" on instagram.

[greglepore]

I have a 85 with a similar turbo. I do run a small intercooler for peace of mind. Mine started as a protomotive kit, and I've been happy with their chip and rr fuel unit. I did buy a vems, mainly to eliminate the flapper box, but it sat for 2 years and I sold it as I'm 64 and figured that the time I would spend sorting it all out wasn't worth it with a good running car. If going from scratch I'd probably use it. The car has been pretty much flawless for 10yrs since the conversion, although I did need need a trans rebuild, maybe due to turbo but maybe not.
The rest of the plan sounds good, but I'd ditch the cat unless you legally can't. I like having heat so kept exchangers. I know folks run filters at the turbo but I think that's asking for trouble - my filter is a really large k/n on pipe in engine bay up near rear deck. Protomotive's setup but I like it.
Getting an elbow to work with the stock afm was a major trial and error process..

[Dieter9]

Nice !
Mine is also a 85 Targa !
Do you have pictures of your setup ?

I was thinking about a small ic.. what size did you go for ?

[Dieter9]

guys, wanted to update my wrong title but it doesnt show up .. ?

[Dieter9]

hi,
i was thinking of using this RRFPR ?
Ist 1:1.7 rising rate.

Any ideas if it will work ?

[scottrx7tt]

It’s pretty easy to do. My engine was a 3.0 but I used a 3.2 intake with 3.2 fuel rail and stock lines. The 3.2 FPR will work as a rising rate regulator with a boost line hooked up to it. I did use an aftermarket aeromotive FPR plumbed into the factory lines. I just used a 930 jpipe with 3.2 heat exchangers. I used an eBay CX racing intercooler made for a Mitsubishi EVO and modified the inlet for my application. I ran a k20-7200 turbo with a gravity drain into the sump. I ran a micro squirt ECU with distributorless ignition. I did it all on a budget since slmost all of my parts were gently used. The engine made 402 hp on 10 lbs of boost. Engine compression was 9.5:1. Unless you are running a G50 transmission you will eventually blow 2nd gear into small pieces, ask me how I know! I sold the car a few years ago, and from what I understand is still running goood.

[Dieter9]

thx for your reply !
nice build!

so you say the stock FPR would be enough ? mmmm ..
Yeah i want a stealth build on my non turbo body so i cant use a ic ..

does the micro squirt work out of the box ?

[mikedsilva]

Originally Posted by scottrx7tt

It’s pretty easy to do. My engine was a 3.0 but I used a 3.2 intake with 3.2 fuel rail and stock lines. The 3.2 FPR will work as a rising rate regulator with a boost line hooked up to it. I did use an aftermarket aeromotive FPR plumbed into the factory lines. I just used a 930 jpipe with 3.2 heat exchangers. I used an eBay CX racing intercooler made for a Mitsubishi EVO and modified the inlet for my application. I ran a k20-7200 turbo with a gravity drain into the sump. I ran a micro squirt ECU with distributorless ignition. I did it all on a budget since slmost all of my parts were gently used. The engine made 402 hp on 10 lbs of boost. Engine compression was 9.5:1. Unless you are running a G50 transmission you will eventually blow 2nd gear into small pieces, ask me how I know! I sold the car a few years ago, and from what I understand is still running goood.

OK, so the downside is you blow 2nd gear, but I bet you were having a **** load of fun!

[spuggy]

My $0.02.

Originally Posted by Dieter9

wastegate with 0.5bar (7psi) spring

A 0.5 bar spring rating means that the wastegate will (or should) be *fully open* at 0.5 bar.

This almost certainly means that the valve will crack off the seat long before that. And it's a very weak spring compared to 0.8 bar (you can move it with one thumb on the valve) - and there's a lot of valve area for the exhaust to exert pressure on.

This will leak boost.

One remedy is to run boost control with a 4-port solenoid diverting boost pressure to the top of the diaphragm until the set pressure (which could easily be exactly the same as the nominal spring rating) is reached.

So instead of just the spring pressure alone trying to hold the valve closed against the exhaust, you'll have spring pressure + the boost pressure combined - until it reaches set point, at which point the boost pressure goes under the diaphragm to force the valve open.

Bet you a beer you'll notice the difference. I ran a 3 port solenoid with a 0.5 bar spring & boost control, and there was most certainly a boost leak. Now, the BOV chuffs hard even on relatively gentle upshifts where I didn't think there was enough load to develop positive manifold pressure.

Originally Posted by Dieter9

no bov is needed at this boost level.

BOV valve is to prevent compressor surge surely? This may not damage your turbo immediately, but there's no benefit. BOVs really don't cost much...

With EFI, can usually vent them to atmo without too much problem. Or just recirculate it.

Originally Posted by Dieter9

use a rising fuel pressure regulator

I run an aftermarket FPR, reference port plumbed to the intake manifold. Which maintains fuel pressure differential relative to boost. All you need. Adjustable FPR is also nice - but not necessary - not like you're going to be twiddling with it.

While I'm sure that the Promotive chip is a good product (lot of guys here started with their setup and say good things), I personally would probably go with the VEMS.for DIY. Or Haltech. Or Link. Or AEMS. Or Emerald. Or MegaSquirt. Or, or, or...

The standard advice is to fit whatever your tuner is most comfortable with, if you're not going to be doing it all yourself.

MoTeC seems full-featured (lol - once you spring for the option pack(s) you need), intuitive, flexible and drama free to me; my M800 does the job just fine and I feel no need to upgrade to the latest/greatest M130 (which does a bunch of stuff you don't need for an old engine like ours). But MoTeC are really not aimed at the low end of the market at all - a lot of their business is from Pro teams, the CAN-BUS add-ons like soft dashboards, driver switches, as well as the data logging & telemetry, analytics etc...

Plenty of guys have good results with plenty of other ECUs. Almost any/all of which I think are likely going to be more flexible than chipping the Motronic.

Going aftermarket for the ECU means you can run a MAP/RPM map - generally preferred for forced induction over Alpha-N (TPS) vs RPM. Simply ditching the barn-door (AFM) will make more power. And you can twiddle fuel/ignition trims to your liking.

[kamaro]

Check my old thread for a detailed info when I turbo'ed my 3.2 :

3.2 Turbo project : Final Verdict + total cost.

Good luck!

[Dieter9]

Originally Posted by spuggy

My $0.02.



A 0.5 bar spring rating means that the wastegate will (or should) be *fully open* at 0.5 bar.

This almost certainly means that the valve will crack off the seat long before that. And it's a very weak spring compared to 0.8 bar (you can move it with one thumb on the valve) - and there's a lot of valve area for the exhaust to exert pressure on.

This will leak boost.

One remedy is to run boost control with a 4-port solenoid diverting boost pressure to the top of the diaphragm until the set pressure (which could easily be exactly the same as the nominal spring rating) is reached.

So instead of just the spring pressure alone trying to hold the valve closed against the exhaust, you'll have spring pressure + the boost pressure combined - until it reaches set point, at which point the boost pressure goes under the diaphragm to force the valve open.

Bet you a beer you'll notice the difference. I ran a 3 port solenoid with a 0.5 bar spring & boost control, and there was most certainly a boost leak. Now, the BOV chuffs hard even on relatively gentle upshifts where I didn't think there was enough load to develop positive manifold pressure.



BOV valve is to prevent compressor surge surely? This may not damage your turbo immediately, but there's no benefit. BOVs really don't cost much...

With EFI, can usually vent them to atmo without too much problem. Or just recirculate it.



I run an aftermarket FPR, reference port plumbed to the intake manifold. Which maintains fuel pressure differential relative to boost. All you need. Adjustable FPR is also nice - but not necessary - not like you're going to be twiddling with it.

While I'm sure that the Promotive chip is a good product (lot of guys here started with their setup and say good things), I personally would probably go with the VEMS.for DIY. Or Haltech. Or Link. Or AEMS. Or Emerald. Or MegaSquirt. Or, or, or...

The standard advice is to fit whatever your tuner is most comfortable with, if you're not going to be doing it all yourself.

MoTeC seems full-featured (lol - once you spring for the option pack(s) you need), intuitive, flexible and drama free to me; my M800 does the job just fine and I feel no need to upgrade to the latest/greatest M130 (which does a bunch of stuff you don't need for an old engine like ours). But MoTeC are really not aimed at the low end of the market at all - a lot of their business is from Pro teams, the CAN-BUS add-ons like soft dashboards, driver switches, as well as the data logging & telemetry, analytics etc...

Plenty of guys have good results with plenty of other ECUs. Almost any/all of which I think are likely going to be more flexible than chipping the Motronic.

Going aftermarket for the ECU means you can run a MAP/RPM map - generally preferred for forced induction over Alpha-N (TPS) vs RPM. Simply ditching the barn-door (AFM) will make more power. And you can twiddle fuel/ignition trims to your liking.

thx for your reply !!
what FPR do you use ?
i was told a 0.5bar (7psi) will be max on the stock 3.2 ? thats why i referred to it..
the BOV is als something i read that most turbo's now are anti surge so..

[Dieter9]

Originally Posted by kamaro

Check my old thread for a detailed info when I turbo'ed my 3.2 :

3.2 Turbo project : Final Verdict + total cost.

Good luck!

Thx man!
saw the tread long ago but will have to read up.. not planning on going that ecu tho ..
is the car still going strong?

[kamaro]

Originally Posted by Dieter9

Thx man!
saw the tread long ago but will have to read up.. not planning on going that ecu tho ..
is the car still going strong?

Yes it still going strong, and became bored with the low boost I just got myself a set of good used 3.3 pistons and cylinders to lower the CR to go to upto 15 psi or so of boost.

[spuggy]

Originally Posted by Dieter9

thx for your reply !!
what FPR do you use ?

I forget. It's black. Plenty of well-made and perfectly good aftermarket FPRs once "original" isn't a concern.

It's a chamber with a spring/diaphragm, two fuel ports below and a vacuum port above the diaphragm - not exactly rocket science. A fuel pressure sensor port (for datalogging) or the ability to adjust spring tension for desired fuel pressure without dismantling/shimming is nice - but this isn't something you need to do very often.

Originally Posted by Dieter9

i was told a 0.5bar (7psi) will be max on the stock 3.2 ? thats why i referred to it..

You don't want to be leaking boost as you approach the set limit, whatever that may be.

And, IMHO, the "safe boost level" conversation changes entirely (or should) with accurate fuel/ignition control. And/or adaptive knock sensing/control. Entirely another conversation - suffice it to say that some folks run a lot more boost than factory without lowering the static C/R to ridiculously low levels.

Regardless, ideally, you would retain 100% of whatever boost you make, even at 99% of your set boost limit.

However, a wastegate with a spring simply doesn't behave like that, as it will crack the valve off the seat before the rated pressure - again, wastegate spring "rated pressure" is the "will be fully-open at X pressure" rating. They will start to open before that rated pressure unless controlled.

If the manifold pressure achieved even bears any resemblance to the wastegate spring rating in your car. This is affected by many things, including header design - especially of the wastegate junction. Many less-than-optimally designed headers exhibit "boost creep", where pressure achieved/maintained is higher than the wastegate rating.

Another thing that can influence when the wastegate cracks is exhaust backpressure. I thought an open exhaust was truly obnoxious, personally. And may be prohibited by law many places... A more restrictive muffler will develop more backpressure, which will be "seen" in the headers - and so the wastegate.

The "early cracking" behavior only becomes more obvious with a low spring rate that can't keep the valve closed against exhaust backpressure. If you have to lower the spring rate further to actually achieve your desired boost pressure, it'll will get worse. IMO.

Originally Posted by Dieter9

the BOV is als something i read that most turbo's now are anti surge so..

A BOV is a $50-100 part that prevents compressor surge on closing the throttle. Entirely.

A very brief google search led me to this random quote I selected from a dozen or so saying much the same thing:

An anti surge housing is designed to prevent that. It is not designed to take the place of a BOV. it does not relieve the shockwave made by slamming the throttle shut and sending 20+psi worth of airflow backwards in the charge piping and stalling the compressor wheel. it is designed to relieve pressure ON Throttle. It is designed to move the surge line over on the compressor map. Thus the ANTI SURGE. Surge under WOT is 100X more destructive to a compressor wheel/bearing assembly but both are still not good and improper for turbo health. Whether this 'works' for some people is besides the point.
A "race car" running systems in place to pull power when shifting or 'no lift shifting' dont run BOVs because a fully closed throttle blade after WOT at 20+ PSI of boost is rare.
A street car doing multiple aggressive WOT to closed throttle like most of you guys do every day absolutely must have a means to relieve intake pressure.

^^^ That's, in pretty general terms, what I understood/was given to believe (although I won't swear to the accuracy of the numbers, seems like they might be exaggerated to make the point).

I don't get compressor surge on WOT. I run a 50mm Tial BOV - and don't get compressor surge on (old school, close throttle, clutch'n'stick) shifting either. Works for me.

[greglepore]

I'll get photos later today.
Agree that the boost controller is a good idea-I've been meaning to plumb one. The spring isn't instant, so yeah, you'll leak a bit of boost without. FWIW, not as much of an issue with the modern turbos but still. Also make sure you have a visible boost gauge, I run a small vdo in clock plug.
Another thing-make sure your wastegate is large enough. When I went from the stock turbo with the protomotive kit to the current turbo, I found that the khs style wg that came with the kit would creep boost up to about .7 bar in 4th under high rpms - just not enough flow. I run an intercooler and don't often run that fast, so haven't corrected it yet.
Killing second gear isn't inevitable if you drive conservatively-drive like you're aware that 2nd is weak and you'll be ok.
I also run a tial 50mm BOV and an ebay intercooler. They're cheap and look sketch but they work ok.
As to the ecu, while the Proto chip is very simple, the full featured ecu's give you the ability to run larger injectors, and are flexible if you upgrade.
One last thing-if you still have stock a/c, be very aware of plumbing and clamp orientations-I've deleted my a/c, but when it was there I punctured the tail condensor with a t bolt on a clamp oriented too high.