Talk me out of/into a Turbo conversion

[75 911s]

I recently acquired an 87 3.2 long block. I've torn it down and the plan is a 3.4. The motor did not come with intake or exhaust so I was going to run an EFI / ITB setup with some racing headers. Motor was slated to go in my 75 911.

I have to admit I've been inspired by the boosted brothers build and since I'm at the start of the build I'd like to at least consider and price out a turbo conversion.

Why or why wouldn't you build a turbo?

Just how much more will all the turbo components cost?

I think the intake might actually be cheaper as I would buy a stock 3.2 intake and run EFI on that with the right injectors as opposed to ITBs which are an additional 2-4k

I think the exhaust would be more expensive for obvious reasons.

I'm emissions exempt. Car is street/show

Budget is flexible and I'm building it over a long period of time. Shooting for a Dec 2018 completion.

I've never even driven a Turbo.

My narrowbody car has 6" in front and 7" in back on 225/50. Would this be stupid? If I did build a turbo, I might look around for a widebody roller.

Thanks for any input and or resources. I have Bruce Anderson's Performance Handbook, but looking for any contemporary knowledge.

[Tippy]

Why would you turbo a 3.2? Because it has the same low end as the 930 does except the oil pump.

2nd, it has a higher flowing intake, higher flowing heads, and larger camshafts over the 930's.

It's a win-win.

I may have a 3.2 intake for sale.

[Tippy]

Some totally rough numbers.......like really rough (search for better numbers):

1. Rarly8 or B&B 930 headers - >$2000?
2. TiAL F46 wastegate - ~$500 (bolts right up to 930 headers) or TurboSmart - much cheaper
3. Blow-off valve, TiAL, TurboSmart, HKS, GReddy, etc. - $ all over the place
4. Intercooler - TurboKraft for nicest, Treadstone, eBay specials - $ all over the place
5. Injectors - ID1000's (probably the best in the market) - >$700? or Siemens Deka 875cc's - got mine for only $300 on eBay
6. MegaSquirt, AEM, MoTeC, Holley, F.A.S.T., SDS, Link, etc., etc., etc., etc..... - $ all over the place from $500 up to like $10,000
7. Mahle turbo 98mm P&C 7.5:1 CR (if you want high boost in the future) - ~$5k?
8. Bosch 044 fuel pump - $150 and up (lots and lots of counterfeits out there!)
9. Borg-Warner S256, S360, S362 - $750 and up or Garrett GT35R - ~$1200 and up or Turbonetics 60-1 - ~$750 and up
10. KEP stage I or II PP (to hold added torque) - $650 - 750

[TurboKraft]

Upgrade the oil pump and piston squirters, and you've got a great foundation for a Turbo engine.

EFI+ITB *and* pistons & cams, and lightweight rods (or at least rod bolts) and that's a fun non-turbo engine capable of 280-300hp on pump gas. Like a 3.0L GT3RS. Won't murder the 915 transmission, either.

But any version of Turbo pistons, with EFI and standard 930 go-fast parts (headers, GT35R, intercooler) and it'll make 500whp without hardly effort. You'd probably have to neuter it with a standard 930 J-pipe turbo-WG pipe and a K27 to keep the 915 in one piece.

[quattrorunner]

Even with those parts mentioned above that are to keep it underpowered as Chris says you’ll still probably kill the 915 gearbox.
So figure into your conversion another $10-20k for proper transmission mods.
That being said turbo power amazing. I love it. But to do it again I would be scared knowing what I know now all financially.
It’s espensive!

[quattrorunner]

BTW I'm in Vegas, Should have mine back on the road in the next couple weeks if you'd like a ride along. I don't trusty just anyone to drive it these days......

[Hill3312]

I tried my absolute hardest to keep things "budget oriented." Even with cheap headers and a tractor turbo the build easily exceeded 15k.

- Bottom end rebuild - 6.5k
- Lower compression pistons- 1.5k
- Head rebuild (port and polish) - 2.7k
- Headers, ECU/ EFI kit, misc turbo junk (wastegate, intercooler, bov, etc) 3.5-4k

... I'm not done yet, the car doesn't run. So who knows how much more it'll cost. Will probably be worth it, that's what everybody keeps saying.

[1979-930]

I think most of the costs in his build are accounted for N/A or Turbo.

The added costs will be
GT35R Turbo with install parts $2350.00
Dual WG $750.00 <-- Why not dual if starting from scratch.
Intercooler with install parts $2,200.00
Other Turbo Engine costs ?? Maybe $3,000.00

I think the added cost will be around $10k to go Turbo.
If you have it to blow then go for it. If it's going on a C.C. Don't!

[Mr9146]

Buy a 3.6 ...

[TurboKraft]

Originally Posted by Mr9146

Buy a 3.6 ...

Yeah, but those aren't exactly cheap any longer, most seem to need at least a top end rebuild, then adapt it for the earlier chassis... That all adds up really quickly as well.

[spence88mph]

This is my engine, made 320WHP with 0.5bar in 2009ish, ran in the current configuration since without any issue until recently, it started blowing smoke, tore the engine down completely, split the case etc. Only thing that needed doing were 2 valve guides. Put some ARP rod bolts, new rings, some cleaning and gaskets and its back ready to go once my clutch arrives. I am going to add an W/A intercooler, VEMS, soon but getting it running first. I highly recommend this route, the car is proper fast.

Parts:

Garret GT30R 3071
Protomotive RRFP
Protomotive Stage 1 Chip
Protomotive Charge Pipe (no intercooler)
Rarely L8 Muffler
TiAL 46mm Wastegate
Oil line to turbo

Good luck!

[flat6pilot]

Parts list from my 1980 SC conversion. (360whp/324tq)



In addition to that, I already had this:

CARRERA MANIFOLD - $700
MEGASQUIRT MSII IGNITION (FUEL ONLY) ~$2500 (Give or take...)
MSD IGNITION - $300(?)

Good luck! I'm hooked on turbo power now...

My turbo thread: http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/880468-another-911sc-turbo-conversion.html

.

[LOWFAT]

It can also depend on your driving style and the kind of roads you have available to you. Tight twisty roads staying naturally aspirated will be the better choice as the car is more controllable and more enjoyable. If the roads are a little more open with long flowing curves or a lot of highway driving the turbo wins hands down. I do a lot of spirited driving with a couple of my friends who have a 3.0 SC and a 3.2 Carrera. On most of the loops we frequent their cars are much faster until the straights where the turbo's power comes on and I shorten the gap very quickly. The sound of the turbo spooling and the jump to light speed never fails to put a smile on my face. I'd like to get either a SC or a 3.2 for myself at some point to make a proper back road burner. I do plan to do some suspension upgrades this spring and that may help tame the 930 a bit more but I still think a naturally aspirated car would be faster for our roads where I live.

[RarlyL8]

You could go a couple ways with a turbo build; keep the 915 and build an ultra quick spooling mild turbo engine that would be a riot to drive in the twisties or add a 930 tranny and build a yellowbird killer. Either way would be tremendous fun!

[Tippy]

Originally Posted by RarlyL8

You could go a couple ways with a turbo build; keep the 915 and build an ultra quick spooling mild turbo engine that would be a riot to drive in the twisties or add a 930 tranny and build a yellowbird killer. Either way would be tremendous fun!

Brian, beings that he is starting from a 3.2, keeping the 915 from grenading will be next to impossible, unless he uses stock 930 bits.

But what fun is that?!?!?!

I'd think he has an easy 100hp/80ft/lb torque advantage stock to stock between his 3.2 and a 930 engine??? No??

[Tippy]

Originally Posted by flat6pilot

Parts list from my 1980 SC conversion. (360whp/324tq)

In addition to that, I already had this:

CARRERA MANIFOLD - $700
MEGASQUIRT MSII IGNITION (FUEL ONLY) ~$2500 (Give or take...)
MSD IGNITION - $300(?)

Good luck! I'm hooked on turbo power now...

My turbo thread: http://forums.pelicanparts.com/911-930-turbo-super-charging-forum/880468-another-911sc-turbo-conversion.html

.

Kyle, that is my kind of build! Love the "grassroots" stuff. Nice numbers!

[Tippy]

Originally Posted by spence88mph

This is my engine, made 320WHP with 0.5bar in 2009ish, ran in the current configuration since without any issue until recently, it started blowing smoke, tore the engine down completely, split the case etc. Only thing that needed doing were 2 valve guides. Put some ARP rod bolts, new rings, some cleaning and gaskets and its back ready to go once my clutch arrives. I am going to add an W/A intercooler, VEMS, soon but getting it running first. I highly recommend this route, the car is proper fast.

Parts:

Garret GT30R 3071
Protomotive RRFP
Protomotive Stage 1 Chip
Protomotive Charge Pipe (no intercooler)
Rarely L8 Muffler
TiAL 46mm Wastegate
Oil line to turbo

Good luck!

Nice numbers for non-intercooled! But, I can't help but think, for a little bit of money, how much more power you'd make with one. I paid $500 for a V8 designed intercooler from Treadstone. It has a 15 degree raked back inlet (was made to go in front of their radiators) that I cut off, and rotated 90 degrees aiming towards the throttlebody. Then, I removed the outlet and mounted it 90 degrees on the outlet tank and welded in a plug to where the outlet used to go. Did all this a MIG and spoolgun. Took about an hour.



Or, you can get a ridiculously cheap one from CXRacing. I bought one initially, it has a 5" core!!! It was only like $215. It was a horizontal flow, and in my mind, was going to be a restriction (not likely at all, after seeing high power cars with this design), so I opted for the vertical flow (Treadstone above of course) that every 911 turbo aftermarket house uses just to be safe. Was going to have to rotate the left tank 180 degrees, was the biggest hurdle too.

[75 911s]

Wow what a great group of responses! Thank you to everyone who has given input so far. I obviously have a lot to research. I was entertaining the turbo just as due diligence to consider all options while I have the motor torn apart, but hadn't really seriously considered it...until now! Now I'm flat out excited about it!

Quattrorunner, would love a ride along when you get the car back.

One interesting thing is that when you pop the decklid on a turbo car, you get an intercooler... It's a lot less pretty, but it definitely says "turbo power!" This would allow me to change up some of the cosmetic stuff I had planned and implement a more basic, but clean, engine bay.

Tippy you mentioned the stock 3.2 intake and cams being bigger which is an advantage. I had planned on replacing the cams with something more aggressive for the ITB setup, but with the turbo setup, you are saying I could regrind my stock cams and save a little money that way?

Also what's the deal with twin spark in regard to Turbo? My understanding of it is that it helps with higher compression engines, and since Turbo, by their nature are lower... I shouldn't need to go twin spark anymore.

Thank you again to all the contributors!

[Tippy]

Originally Posted by 75 911s

Tippy you mentioned the stock 3.2 intake and cams being bigger which is an advantage. I had planned on replacing the cams with something more aggressive for the ITB setup, but with the turbo setup, you are saying I could regrind my stock cams and save a little money that way?

Also what's the deal with twin spark in regard to Turbo? My understanding of it is that it helps with higher compression engines, and since Turbo, by their nature are lower... I shouldn't need to go twin spark anymore.

John Dougherty a.k.a "camgrinder" from DRC cams, can grind the stock 3.2's to the popular and sought after 964 grinds up to 993SS (super sport) if you beg him.

If you are running flat-top pistons, twin-plugging is not as needed as the general consensus goes, but is said to be safer and makes a little more power. If you are staying at lower boost levels, probably not all that worth it. But, "cgarr" here can do the twin-plugging to your heads for a pretty reasonable price if you must.

[Tippy]

Duane, I made my intercooler brackets/mounts from aluminum strap from Lowe's or Home Depot. Cheap as dirt and bends easily in a vise to whatever angle you need. Easy to drill through and cut to size too.