HP Junkies Turbo my 3.2 Part 2 - Page 3

WydRyd · 03-17-2002, 02:11 PM

Richard, The 915 will handle high 400's (HP). Anything higher, a G50 or 930 g'box is recommended.

Colby, if you make an extension pipe from the SSI's output that mounts the turbo's on the sides of the engine, slightly higher than the lower valve cover, you can get away with gravity drain. The centre section of the turbo should be between the 1st and 2nd cylinders, then you just weld on a drain pipe onto the valve cover and plumb it back to the turbo's oil outlet.

You won't get over 300HP with only 4psi. At 7psi, the 3.2 will make approx 320 crank HP (stock C/R, non-intercooled) - this is a practical, consistent result attained by Mike and Juan on their blown 3.2's. At 4psi, you'll probably see around 250HP. You can easily run 7psi non-intercooled at stock C/R. Just make sure you have appropriate fuel supply (pressure reg & CHIP) and retarted ignition in boost (remapped CHIP). I highly recommend you get the Fuel Press Reg and remapped Motronic CHIP from Protomotive as these guys have mastered this bolt-on turbosystem stuff.

Either way, your twin setup will be an interesting ride once done. I'd probably go with what Mike suggested and get some T3's instead of the T25's. The T25's will run out of breathe and won't be suitable for high rpm. I think these peak at approx 4500rpm, falling off soon after. They're great for low to midrange applications. The T3's will allow you more breathing room higher up. A T3/T4 hybrid - well, even nicer ;-)

Colby · 03-17-2002, 05:43 PM

Merv, I agree w/ you that the T25's were a bit too small, which is why I started looking into the T3's (as used on the Saab 900, early models only having oil-cooled which is what I want). I think his post recommends me staying w/ the T25's, and I don't know why. I like your idea about the oil drain plumbing into the lower valve covers! I planned to mount them as high as I can, so I think you idea is doable (plus it will make things so much simpler). I am buying the tools this week (pipe cutter, welder, etc) and should have the first of many custom flanges in the work in the next couple weeks, so this should really start progressing soon.

For all of you wondering, the price I am doing this for is astoundingly low. I am getting almost everything used, but in good condition. I know basic welding, but for the intricate stuff (cutting flanges, or crucial pipe welding) I have a friend at Midas. So far this is the expected costs:

T3 turbos: $150 each (Ebay, junkyard, etc)
IC: $400 (EBay, rice forums, etc.)
Adj. fuel pressure regulator: approx. $100
Custom chip: approx. $200
Flanges (exhaust to turbo inlet, turbo outlet to exhaust) $20
each (use factory gaskets as a template)
Wastegate: internal, none needed
Blow off valve: 1st generation Eclipse, $15 (for now, may
upgrade later)
Misc. hoses, fittings, etc (I'm sure they're will be plenty): $150

By going this route, I can get everything together, lined up, and working and then upgrade as I go. Also, initial start-up costs are kept minimal (twin turboed for just over $1000???) and I can go as wild as I want as money becomes more available. I'm not doing a "ghetto" slap-together job; conversely I'm being sure to do it right the first time, just with used and readily available parts.

Colby

WydRyd · 03-17-2002, 06:04 PM

Sounds good Colby! Keep us posted on your progress. Always interesting to see fellow 3.2'ers think outside the square and try something different. There is a dude on the 911-Rennlist who has Supercharged his 3.2 Carrera and has had excellent results.

I must bring to your attention that since you are running stock compression ratio of 9.5:1, you need very efficient intercooling if you want to run 10psi boost (0.7bar). Anything under 75% efficiency is questionable, in terms of reliability at that boost level on stock C/R. If anything, I'd spend a bit more in the intercooler to ensure you have a highly efficient intercooling solution. Mike, Juan and myself are running massive intercoolers, fabricated by a local Australian mob called Aluminium Radiators & Engineering (www.are.com.au). These measure 29" x 10" x 3.25" and are designed for max cooling efficiency by distributing the charge air across the top face of the core, resulting in higher efficiency.

Gravity oil drain WILL work. Just needs proper positioning of the turbo to take advantage of this setup. I'll get some snaps of my setup and post it online so you and others can see what I mean. The centre section of the turbo needs to be rotated approx 30 degrees towards valve cover in order for the oil drain to point in the right direction/angle for it to work properly.

Another consideration here is oil pressure. Since you are running twin blowers, you *MAY* need a higher flowing oil pump, such as a 930 unit. Not sure, but worth looking into. Mike may have a better idea here as he's the mechanic ;-)

Just something to be weary of in your adventures...

Colby · 03-17-2002, 06:39 PM

I tend to use a MASSIVE intercooler (core approximately 10x19x3). With end tanks, it should take up most of the turbo tail. It will be a quality piece (spearco most likely). On Ebay, and other rice groups they are always selling their front mount IC's for around $4-500. The catch is these are usually side to side w/ one inlet/outlet. But occasionally a top to bottom pops up (which I need, as my turbos will come in from the bottom and then out through the top to the MAS). Then I just need to weld on a second inlet and I'm good to go. I pulled my engine heater blower this weekend to make more room for an IC. I wouldn't turbocharge any car w/ any boost w/o one!

Colby

WydRyd · 03-17-2002, 06:54 PM

Colby, are you using a 930 Tail?

That's what I have and I also had to remove my heater blower ducting. I'll be relying on the interior side kick panel blowers to move the heated air. I think I lose heater speed selection. Oh well :-(

I'm told with the larger tails, like the C2T 3.8 RS tail, you can retain the heater blower because the higher tail and grill allows you to mount the IC slightly higher, just clearing the heater blower.

Anyway, not too fussed about that because the side kick-panel blowers will work fine.

WydRyd · 03-17-2002, 07:18 PM

Ooops! Sorry, just looked at your WEB page. You have a Carrera tail.

I think you will have problems fitting an intercooler under that tail.

I have a factory turbo tail on my Carrera Cab, but it's bolted onto a Carrera deck lid. I had to get my deck lid cut by a body shop, along where it mates with the turbo tail, so I can fit in the intercooler in. You'll have to do the same too I believe, since your core is also 10" deep.

You'll lose your tail mounted air-con condensor too.

Colby · 03-17-2002, 07:38 PM

You must've only seen the first pics on my site (of when I first got it). Look at the bottom for the more recent pics. I too have a turbo tail mounted on a Carrera lid. I already cut the lid to match when I mounted it. I also have pulled the AC. I'm right there with ya!

Colby

WydRyd · 03-17-2002, 07:45 PM

FANTASTIC! You ARE prepared aren't ya!

Good going!

What do you plan to do with the condensor? I'm getting a PerformanceAire under-pan unit from the USA. S'pose to improve air-con cooling substantially! 45" x 14" I believe - ONE BIG MUTHA!

Also, do you have a secondary oil cooler behind that front spoiler?

Colby · 03-17-2002, 07:55 PM

I pulled EVERYTHING from the AC, including all the junk up front. I now am in the process of sheetmetal'ing shut all the gaping holes left behind. With the AC stuff gone up front, it opens a some big possibilites as to what to do up there... brake cooling ducts, oil coolers, etc.

So far no I don't have a front mount oil cooler. I haven't had the need YET. I am sure with the turbos being cooled by the same oil that cools the motor I will soon find myself needing additional oil cooling capabilities. I don't like the traditional method of front mount oil coolers. They are so scrunched in there air flow through them seems compromised. So I was considering cutting two holes (well, one is already there from the AC) and running fans behind it, or I may run the oil cooler under the pan and use holes from above (and ducts running up front) to cool it. This is definitely later on though; I have enough projects right now to keep me busy.

I'm not sure if you saw my other thread, but when I pulled my engine blower, my footwell blowers quit working also. Any idea on how to get them to work? The 1,2,3 knob between the seats, does that control the speed of the engine blower, the footwell blowers, or both?

Colby

WydRyd · 03-17-2002, 08:01 PM

The 1,2,3 control in-between the seats controls the engine blower I believe.

Any idea Mike?

Colby · 03-17-2002, 08:04 PM

I thought the little metal tabs under the red levers (makes contact when you pull them up) turned on the engine blower, and the 1,2,3 knob controlled the footwell blowers.

If not, what turns on the footwell blowers?

Colby

Mike the mechanic · 03-17-2002, 08:11 PM

Hey mm86911, I would love to meet up with you when you come to town. We'll arrange when the time comes.
Colby, I too once was considering a twin setup, I was looking for a used set od SSi's but to luck. I found that the t25 off the 2nd gen DSM to be right on. Firstly, the t25 was undersized when on the 2.0l Mitsu, made 210 hp and you could bump it up (stock turbo) to about 250hp. Our engines are essentially two three cylinder 1.6 liter engines (well not really but bear with me...). I can't imagine a 1.6 with a T3, unless of course your looking at huge amounts of flow, which also means huge amounts of turbo lag. I find the t25's maps to be better suited to each half of the 3.2. Secondly, remember the BMW alpina B10 biturbo? Thats a 3.5 liter 6 cylinder that made 450 hp with two t25s. Do a search, you'll see. If you want more than 400 hp, then go with suitably matched T3's, but be careful! There are many many configurations of t3's out there.
About the oil drain, the return isn't pressurized, it sort of drips out of the turbo, which is why oil drain tubes are large in diameter. Merv's idea is best, less hassle than running a pump and less things that can go wrong.
About fuel, you are right in assuming you don't need injectors right away, a rising rate fpr will do the trick. You can't get too much more fuel from a custom chip, since the DME cannot sense boost, you can't program a chip to supply extra fuel under boost. The boost sensitive fpr is good. The chip should be made to supply a less agressive timing curve.
About the oil pressure to the turbos, I really doubt you will need a higher flowing oil pump as Garret turbos require less pressure than most other turbo manufacturers. When 930 owners upgrade to a Garret from KK#, they have to use a restrictor in line with the feed line. They shouldn't receive more than 5 psi of oil pressure each, at idle, if they get more, they will most probably spew oil smoke. (25 psi at full load)

Mike
86 Carrera t

WydRyd · 03-17-2002, 08:28 PM

Colby, have a look at this WEB site http://www.type-911.co.uk/exhaustparts.htm. there's a few links here that explains the whole heater system for our cars, under "Problems with your heating system on Pre-1989 911's?".

G'Day Mike! Richard has been holding onto your intercooler on the hopes that I could provide him with exact measurements of my outlet pipe -> AFM, but I TOLD HIM AGAIN, that I won't have mine back for 2 weeks or so and that he shouldn't make you wait THAT long. Anyway, he's shipping today I'm told! I told him this weeks ago, but for some reason he held onto it. Maybe he misunderstood what I told him. Anyway, you will have it soon!

dickster · 03-18-2002, 07:17 AM

Quote:

Richard, The 915 will handle high 400's (HP). Anything higher, a G50 or 930 g'box is recommended

that would be more than enough for me!

i hope to do a turbo/surpercharger install when funds allow - also got to get the rest of the car up to scratch first.

what makes you guys go for one over the other (turbo v super)??

do brakes need upgrading on a 3.2 before converting?? (what brakes??)

appreciate the info and the interesting read.

RarlyL8 · RarlyL8's Garage

The high mounted turbos sound interesing, but I have a couple of questions.

One - I can't visualize how the turbos would physically fit in this space and not interfer with anything. Got a picture?

Two - just exactly how do you plan to adjust your valves with all this stuff in the way?

Colby - I don't live too terribly far from you. I'd like to drive the posermobile up and see this work in progress some time if you don't mind.

Colby · 03-18-2002, 05:06 PM

Ok, why I prefer turbos over sc's. 1) 'Cause I know em better. I started out racing Turbo Talons and gained a wealth of knowledge from them. I know a little bit about SC's though. 2) SC's have less lag, but are less efficient (generally). Good luck getting 25-30psi out of a SC (thats what I ran on my Talon w/ race gas). As the boost goes up on SC's, the air temp gets way high, and you risk overspinning (not to mention slipping belts, etc.). I just like turbos.

When I say mounted high, I just mean higher than the heat exchanger output (but below the sheetmetal). They will still be down low, as in not in the upper portion of the engine bay. They will also be behind the motor, not on the sides, so access to the valve covers won't be impaired.

Sure, once its started (probably next weekend...still gathering parts this week), come on down!

Colby

expat · 03-18-2002, 07:01 PM

Just words of encouragement - please keep posting about what you are doing. I'm sure there's lots of lurkers like me given the number of reads on this topic.

Cheers
Mark

WydRyd · 03-18-2002, 07:26 PM

Basically, turbo engines don't suffer from the 'parasitic' loss of supercharged engines. Typically, a supercharged engine will be down 30-50HP at the same boost level as a turbocharged counterpart at those power levels. For e.g: a supercharged 3.2 engine *may* put out 370HP at 10psi, whereas a turbocharged 3.2 engine at the same C/R and boost *may* put out closer to 400HP as it doesn't suffer from the parasitic losses of S'Chargers.

Colby, for proper gravity drain to work, the turbo needs to be side mounted, next to the valve cover, between Cyl's 1 & 2. You don't want the return line(s) to be toooo long.

In order for the turbo to fit there, some frame clearancing needs to be performed around the tow hook area. Nothing major really.

With any substantial power increase, upgrading brakes & suspension should be the first thing to do before seeking more power.

Luckily, I have a factory turbo optioned Carrera with the nice 930 options, such as brakes, suspension & body. Suspension has been upgraded to Adjustable KONI Sports all round for a firmer ride. I'd like to upgrade my torsion bars and fit some adjustable sways too in the near future.

Car should be ready end of this week! HANGING OUT MAJORLY!!!!!

dickster · 03-19-2002, 12:07 AM

strange, i imagined that i sc would run cooler! that was one of the reasons i swayed that way. (apart from the sc conjuring up a more "romantic" image!! - we don't get many in the uk)

so there's really not much difference in running temps??

what about cooling down the units before shutting the engine?? you have to do that with a turbo (to ensure long life), right??

hope you don't mind all the ignoranus questions

thanks

juan ruiz · juan ruiz's Garage

You guys are out of control!!!!!!!!
I wish i was home to post a picture of one of the hot rods that they are building at the camp ,is related to the location so i will try to explain as simple as posible,this is a 3.4 engine that they are turbocharging they are using TWO small turbos from a Nissan Skylite( i think thats the name can remenber the hot rod nissan) the turbos are VERY SMALL both together don't make one of mine estimated HP a WOPPING 400 borther line -,just so you know, the main reason turbo lag (but thats another story) so they are mounting them (picture this) right under the license plate under the rear bumber and they are WAY out of the way of the valve covers they make this short pipes to mount them the cleaver thing is that the pies have catalytic converters( boy i love california) and they are cross so if you look from the rear of the car the turbo on the left is conected to the right side and viseversa a great idea for the room,but of couse that car is a 996 with a $ 70,000 body kit,(is the one with the big scoop on the roof)and it has two small intercoolers mounted inside the rear fenders.
I thing is a very interested proyect if you are saving all that $ then we can install a DTA Mang Sytem that will take care off a LOT of problems like lag you can program it so the full boost comes at certain rpm and so on.

Regards Juan
http://MY88911.homestead.com/newwebpage.html