Adding a turbo to a 76 911 3.0

[cglasco]

I am new here and I am sure that this has been done before so I am hoping someone can help me out. I bought a 76 3.0 engine a long while back it had no SN# stamped on it any where and had a old Rayjay turbo on it. So I decided to go a little different route I rebuilt the engine new pistons (JE) and cylinders, (QSC) and yes I did sent them out with the pistons and had them redone as well as I put supertec head studs on the engine. even had the bearings and crank coated. I put a electronic fuel injection (EMS pro) on it as well. I did get it started but before I put the care on the road I destroy my engine. I could use some help on setting up the engine / turbo. As I have on experience with turbos. any help would be greatly appreciated. Thanks

[Raceboy]

Nice engine! And you did it proper way y converting to EFI first and not doing like most people do it y just slapping it together and then hoping that stock injection system would somehow handle it with stock ignition advance.

First just dial your fuel tale in with some reasonale and safe ignition map and lowish boost, drive it for a while and get to know the engine (its normal behaviour, noises etc).

[cglasco]

thanks I will post more photos of tomorrow.

[cglasco]

Here is my car that has taken a long time to build.

[1979-930]

What compression are you running?
You will set the AFR up a little richer. Your AFR on boost should be no more than 12.5. If you have E10 in your area closer to 12.2.
Idle and cruise can be normal AFR's.

Do some searching in the turbo forum.

[cglasco]

The JE pistons are 10.1 and again I am new to setting up the computer on it. so any help / setting would be great. I was going over the setting the other day and it looks like there are about 100 different fields to input every thing. I am trying not to set this up to race as I promised my wife I would not race it. and around me I only have regular fuel.
Thanks for your help.

[1979-930]

I'm no help with programming EFI. There are some forums dedicated to that. I would find a local shop with experience that can program it for you.
Some of the companies that sell EFI have classes you can take.

[cglasco]

Thanks I look some up. Thanks again.

[WP0ZZZ]

Originally Posted by cglasco

The JE pistons are 10.1 and again I am new to setting up the computer on it. so any help / setting would be great.

That's pretty high for an old turbo engine! Make sure you start with low boost and a good intercooler.

[cglasco]

Thanks here is the intercooler.

[cmcfaul]

I agree, 10.0/1 compression is high for a turbo motor. Half a bar of boost is pressing your luck with detonation. Might be worth the effort to reduce compression a bit. No cost way is thicker cylinder gaskets. Expensive way is different pistons.

Chris

Nice setup oherwise

[cglasco]

Thanks I do have another set of pistons but I don't want to take out the engine to replace them. The engine is a fresh complete rebuild so I think the best thing to do is pull the turbo and run he car as a non turbo. I think that would be the safest and cost the least.

[jpnovak]

Nice looking car. Is it a backdate? Honestly, you will probably get better information if you provide more details on your build. You have a lot of very open ended questions.

What are the full internal build specs? What cams? Boost level will be determined by the dynamic compression ratio - and DCR is a function of piston static compression and intake valve closing angle.

In general, 10:1 is way too high to effectively run any boost and still control cylinder head temps and therefore detonation. You can make it work but you will have to retard timing so much it won't be fun. Better to lower compression and run proper timing.
/
What ECU system are you running? There are many examples of EFI installs on 911s, turbo 911s and 930s. The tuning principles are the same for these examples but the software setups are very different between EFI ECUs when it comes to parameter programming.

[RarlyL8]

Looks like a fun project!
Everything is already there for a turbo so you would need to replace the entire intake and exhaust system to run N/A and generate less power. I'd leave the turbo and turn the wick down to a safe level. If you like that and wish to optimize later on you could size a small turbo for your specific setup. At 10:1 C/R drivability will be the same as N/A, then the turbo kicks in! If you don't like it nothing lost, just continue on with your N/A conversion.

[cglasco]

The ECU / EMS is a EMS pro from EFI Source the car has the stock 3.0 turbo cams in it as well as everything else but the pistons and rods. All bearings and crankshaft have been coated by microblue. Cylinders and pistons as well as a 2nd set of Cylinders were sent to Millennium Tec. for rebuilding / match to the pistons and replating. I do have the original turbo pistons for the car but at some point I like to drive this car without destroying the engine. Cost way to much to rebuild if I destroy that thing. I would like to keep the turbo on it but if it is going to cause a problem then I would rather play it safe. then when I pull the engine again switch back to the Turbo pistons and put the turbo back on it. And I do want to thank everyone for your help. If any of you live in Houston and would like to come by to give any pointers on that thing please feel free I buy the beer. Thanks

[Raceboy]

10:1 is ok with regular water cooled engines plus some nice turbo with generously flowing turbine, 911 with its air cooled engine already requires good flowing turbine to keep EPR/PR ratio at reasonable level. What turbo and turbine are you running?

[cglasco]

If I recall right it is a T3 AR.70.

[cglasco]

Ok after thinking about this and getting all the input from everyone. And also because I already have all the Parts Gaskets and Turbo pistons I am going to pull the engine back out and replace the 10.1 pistons and keep the turbo setup on the car. I let you all know how it goes it is going to take me a little time. Again thanks everyone for your help.

[slow&rusty]

That's an interesting build and a stout looking turbo, so please keep us looped as you progress. I'm glad you're keeping it turbocharged, the power and throttle response is incredible.

As an aside the stock compression on factory 930 cars is 6.5:1 to 7.0:1

Heat and detonation management save engines, sounds simple but takes patience, experience and being cautious.

[Raceboy]

Nowadays no one would want 911 turbocharged engine with 6.5:1 lol. I would either mill those 10:1 pistons down and aim at 8.5-9:1 CR or buy new pistons.