I was going to electronic ignition as the twinplug dizzy I was going to use is bent, so what electronic ignition would you guys recommend?

I'm not familiar with MS ECU you mention in your first post. However, one thing is clear when building a 3.8L turbo - it really needs to be CDI. Either get a new twin distributor (see JB Racing for a killer unit) or make sure MS can handle driving a CDI. If you decide not to use a twin distributor, you'll need to get a CDI that has 6 channels (or a combination). Then you'll need to look at coil combinations too (I use twin pole Bosch where each coil runs both plugs per cylinder).

my motor is twin plug, I'd go a M&W or something like that

DonE,

Side note, is the stock 930 ignition CDI?

1.2 bar 1.4 on 100 octane

Porsche would even ware out one of there best endurance motors in a weekend at those levels.

wifey is complaining about my project cost so I'm just going single turbo, what is the ideal turbo as a single will a Garret t35 be a good choice??

what type & size headers should I get for a single turbo applicatrion on a 3.6/3.8?

I can set you up with headers and a turbo if interested. There are options ...

Brian,

Interested PM sent

you need to read this again, very good advice...

I'm just going to keep my engine a 3.6 single turbo, stock 993 cams and sell my 3.8 P&C's.

If you want someone with a wealth of experience with porsche turbos including 3.6s, 3.8s contact Michael Harris from promotive, certainly not your typical porsche mechanic. He's in Brisbane but will work something out for you, I am likely sending him my engine once I finish a few other projects, very approachable dude.

thanks Spence will do

for those of you who don't know...Reaper's definition of "mild" is 600+HP.

Just a thought, it is a great idea to start with the cams but most of us are working withing some type of constraint.

For many that is the transmission. How strong it is and more importantly what the gear ratios are. Often someone puts high rpm/hp cams in a motor that makes more HP but narrows the power band. Then with shifts if falls out of the juice and the average HP per gear is not that much higher considering all the effort. Might not be that noticeable on the street but on the track it could be.

Starting by matching the cam / power band to the transmission might be something to consider.

If the motor is going behind a stock geared 930 4 speed a strong mid range and 5500rpm HP peak might not make the most peak HP but it might make for a much more drivable car on the track. If it goes behind a closer range N/A G50 5 speed it might be different.

If the pistons are cut down and attention is paid to the valve pockets, the stock 993 cam might be advanced some and work well. Then fitting a turbo to match a strong mid range would be a fit.

One can make a lot of HP but if it is for a track car and reliability is important, might want to reference the factory 993TT and RUF 993 conversion. Most variations ran about 8/1 compression with about .8 bar boost for 400-450hp. Thus a turbo that is in its efficiency sweet spot at 400-500hp or so might be something to think about.

Once you have your goals inline with what makes sense get with the best turbo supplier or Porsche builder you can and have them help you.

I have a lot to learn about turbos but have some thoughts. The GT 35 compressor is nice and at .8 bar is looks like it should work well in the 300-450hp range at .8 bar. Past that and it will starts to loose some efficiency. Going up to a GT40 or GT42 dose not seem to look like a fit or much improvement with making power in the .8 to 1 bar range. They look like they are designed to make power best in the 1.5 bar range.

For the track, there is power and some reliability to be found on the hot side. A small hot side on the street makes for a very drivable car but on the track it makes for increased back pressure and heat at the exhaust valves. A larger turbine might be good for 20-30hp and lower temps but will delay boost some. The GT 35 hot side is not much different than the small K27 turbos and on a 3.6 might hit .8 bar boost as early as 2500rpm. Great for the street bit probably not the best for a track car. I suspect a turbo that hits you boost target in the mid to late 3000's is going to be a better track turbo. Thus a hot side from one of the larger frame turbos like a T4 or the GT40's might be something to consider. The K27 turbos mostly use a T3 sized hot side.

I am not an expert but it might be worth looking at all your options.

I would do some research as there might be something that is a better fit depending on you goals.

911st, thanks for taking the time to help, really appreciate everyone's input I'm a total noob when it comes to turbos.

It will be for mainly street use and the odd track day, not racing, Brian has suggested a k27 HFS with 1.65 headers, which I imagine should work with the larger ports on the 97 993 heads.

The tranny is a 915 from a 81, I have completely rebuilt with stock ratios, wevo single piece reinforced bearing retainer plate, I plan to strengthen the diff side plates and add oil cooling.

I'm not that concerned high massive hp 400 HP is big enough on the street.

Matt

double post

:eek:

911st, I hear what you are saying about NA 3.6, but I'm bored with NA and the $$ head work, cams ITB's efi to get less HP, I want to play around with turbo's for a bit

And your right 915's are very limited, my mechanic has bolted plenty of turbos up to 915's they seem to be fine as long as and he stresses that they need to be re-inforced, bearing retainer, side plates and have the external oil cooler which I intend to do, and not too much HP it was'nt designed for it, and "you really need a 4 speed or G50 for serious HP"

I was going for an 87 roller in which I would put in a G50 with a 3.8 TT setup but my wife has shot that one down so I working with what i have got for now.