Sammyg2’s wild ride! AKA, Turbo SC vs 3.6?

[surflvr911sc]

There was a 914 swap meet at Precision Motion in Riverside today. Ingo called me and said he was there w/ MikeZ & Sam, so being stuck at work I only went by for about 45 mins to see if they had called the cops on them yet. No such luck. I did get a ride in Sam’s Turbo SC so I thought I’d share.

I’ve never been a big fan of turbos but I have never owned one either. The lag thing has always bugged me because I like the power to always be there and the cost has never seemed worth it imo. A stock NA engine w/ a low boost turbo might just take care of both of those concerns.

The kit that he has makes for a really clean install that can be undone in a couple hours, which really impressed me. Sam has taken easy w/ the boost, starting w/ 6 psi but due to possible detonation has backed it off to 4 psi. I think that would be the key to a reliable, long-lived, turbo add on. A driver adjustable boost control could be a very bad thing. I would suggest following in Sam’s footsteps, setting the boost conservatively and enjoying the ride. Time will tell but his 140k(?) stock engine seems just fine w/ the low boost so far. Here are a couple of threads-
Engine is back in and running...sort of
took the turbo on the freeway, woo hoo!

We drove easy for a bit to get things warmed up, and then he nailed it. 3-4k felt like a stock SC, a nice easy push back in the seat and very smooth. After 4k I could feel myself sinking into the seat more and more. At 6k I started to feel the back seat, I’ll be honest, it felt a lot like my 3.6 at 6k- pinned in the seat, hoping you don’t hit any space junk as you enter orbit.

I loved my 3.0 and wouldn’t have done a 3.6 conversion if she weren’t ready for a rebuild anyway. The NA turbo is really cool, it has all the feel and power of a stock NA engine until the boost comes on, then it has quite the attitude. A really great compromise if you ask me.

Overall, I prefer my 3.6; the power is there from the start and it just never stops. The 3.6 is reliable, long lived, and has tons of power in stock form, but it can’t be done for $1000.00, that’s right, $1k. Holy Crap! That is a lot of bang for the buck. This led me to make the Turbo SC vs 3.6 comparison, I think that a low boost turbo kit is a great option for somebody w/ a perfectly good engine, has a little hp bug, but doesn’t want to shell out the cash for a 3.6 conversion. There have also been a few of these that have been on boost for a long time, living happy lives regardless of the naysayers cries of complete destruction. Another great NA/Turbo thread-
911SC Turbo

Thanks for the ride Sam!

[nostatic]

doesn't that beg the question: Can you do a similar bolt-on turbo for your 3.6?

muuhahahaha

[surflvr911sc]

Like I really need to hear that!

I need to save for a track car though. I’ll come up w/ something soon enough, the LA Co Fare is only a few months away and I know my wife will be there.

[JonT]

My thoughts exactly Nostatic--who's going to be the first taker on this challenge? 350 hp would not be out of the question with a low boost system.

[Denis54]

surflvr911sc, what was the compression ratio of the SC turbo engine you test drove? In as far as I know, the follwing ratios have been used over the years:

8.5 for 78 - 79 cars
9.3 for 80 - 83 US cars
9.8 for 80 - 83 European cars

I would feel that the compression ratio of the engine would have a big impact on the amount of boost that can be used.

[surflvr911sc]

I know it was a '80 and I'm almost positive that it was a US, 9.3:1 compression. I agree w/ that assumption Denis, maybe a '78-79 3.0 would be an even better engine to turbo charge.

Jon, you feeling up for the challenge?

[Joe Bob]

I drove it with 6psi and I heard he has backed it down to 4 for today's run....5psi is what he feels would be best....

[sammyg2]

Thanks for the press Dr. Ryan, glad you liked the ride. I think it would be cool for you to be the first 3.6 SC on boost

I backed her down to 4 psi boost temporarily until I get the 7th injector installed and hooked up, then it's back up to 7 psi or so.

4 pounds is fun but not ......quite..... enough. I figure an additional 3 pounds from where it's at now will give an additional 40 hp. he he...cool..he.he.

The difference between when it was at 6 pounds and at 4 pounds was very obvious. Now it rolls on smoothly, almost subtle. At 6 psi it hit harder, still smooth but more like a shove instead of a nudge.

the engine is a 1980 US with 9.3 to one compression and just over 100,000 miles on it.

With pump gas I'll prolly never be able to get much over 8 psi even with an intercooler but that should give around 300 hp, that's enough for me

The best part so far is I haven't broken anything and the car is still reliable to take off on a long trip in.

[Joe Bob]

I drove my new to me, Dakota pickem up to the meet up....MINE already has the extra injectors....nanner nanner.....

Was getting off the 15 freeway to the 60...it has a 20 mph ramp. Some buttbreath in an M5 was on my tail flashing his lights to get bye....I was cruising the corner due the fact I had an engine in the rear bed and didn't want it to shift position.......soon as I got to the straight...nailed it.

Looked down at the speedo and the Vortech blower had me doing 110 with the Beemer about four car lenghts back. Shocked the FUchs outta heem....%^B

Backed off and he went flying bye with a shake of his head....

[campbellcj]

Sometimes I'm kinda glad that I dump all my car money into the 914..which will be eternally NA.

Boost is addictive and can be extremely streetable. But, it can get expensive quickly.

My near-stock Audi S4 is running a GIAC 1bar chip and has a strong, smooth (tabletop flat, in fact) torque curve from 1800-5500 rpm's. The car has two small turbos and 30 valve heads. There is a lot more potential in that car but I'd rather save the money and "risk" for a play car rather than my daily driver.

I have never yet owned a boosted p-car, but a 993tt would be right up my alley. Here's to hoping business is good this year!

[speeder]

I'd love to have that extra "squirt" in my SC, but just wondered, how much do the extra parts weigh? Did you weigh them by any chance, Sammy? And who makes the kit? Intercooled or no?

TIA, and please forgive me if this info exists on another thread.

[thrown_hammer]

Good to hear you got her back on the road Sam. Got any pics?

[sammyg2]

My car is non-intercooled (for now) and the entire installation prolly added about 15 or 20 pounds of weight.
Intercoolers are only beneficial to reduce the intake temperature. As air is compressed it get hot. the higher the compression the more heat. It is not linear and not exponential, somewhere inbetween. Too many other factors, like compressor efficiency, latent heat of system etc.

At low boost there is little heat gain and an intercooler would add no benefit. Intercoolers are restrictive and increase lag slightly, the only time they are worth it is if the intake charge temperature is high enough that additional cooling will increase the air density (colder air=more dense) and reduce the combustion temperatures enough to allow for a little more boost pressure. The point where the intake temperature justifies an intercooler is prolly around 7 psi on an engine like this.

Removing the cat offset much of the turbo weight, eventually I will replace the muffler with something lighter and should end up with a net weight the same as stock.

Horesepower creates heat and increases mechanical stresses.
Additional oil cooling can take care of the heat.
The 3 liter engine is tough enough to handle the additional mechanical stresses IF.......... the combustion temperatures are controlled to a reasonable point and pre-combustion is prevented.

By running the mixture rich the combustion termperature is lowered considerably over that caused by a lean condition.
If the engine is allowed to go lean under boost the combustion temperatures can get hot enough to melt the pistons and wear exhaust valves and guides. Pinging can occur and put incredible stresses on the pistons.
By controlling boost, temperatures, octane, and timing extreme combustion temperatures can be eliminated thus avoiding additional wear to the engine.
I figure I can do that up to 7 psi. Anything over that would carry increased risk. The higher I go the more risk. The biggest limiting factor is the 91 octane reformulated gasoline we have here in So cal.
Water/alcohol injection would make a big difference but I am not a fan of that type of system. Too many things to go wrong.

I just need enough power to keep up with the 3.6s


Mikey posted a picture of the engine a few days ago,

I have some more pictures on my website:
http://home.earthlink.net/~sammyg2/

NOTE: I'm not much of a web builder or photographer.
My wrenches don't fit the keyboard