262's 85 Fiero SE LX9 F23 swap thread lots of pics

[ericjon262]

I'll figure something out. in other news, I just finished re-doing the engine side of the wiring harness (again)... been working on it since 8...

[caffeine]

Personally id rather find an effective simple solution rather than add complexity and weight to the engine bay with a vacuum pump.

I imagine you're already running low on room. Remember you probably want to be able to fix parts on the car without having to drop the cradle .

[ericjon262]

there's not as strong of a vacuum signal at the inlet of the turbo, I may do that though, just weighing my options.

Why use a vacuum pump?

On every turbo conversion I've done, I've had the crankcase connect to the inlet of the turbo, just like OEM turbo cars and never had an issue.

[TGP37]

Well lower octane would only happen under vacuum, not boost, and if you are using a breather to draw in the air then boosting the crankcase shouldn't be possible, at the expense of a boost leak if the check valve failed.

But like mentioned, there are bonuses to having vacuum in the crankcase under boost, so at the expense of simplicity there are more advantages to a vacuum pump or slashcut.

We speak the same truth brother! Join our church and be saved!

But yeah, I like pulling the gases out while in boost. Unlike a check valve system that closes in boost. One of the reasons I didn't go that route.

Of course there is a possibility of a dual use system. Check valved system that recycles the gas at idle and low load. Then once boost kicks in have an electric pump kick on and vac the rest.

[ericjon262]

didn't get a whole lot done today, got the hood back on, and the oil lines/fittings for the turbo on order. I'm going to try to get the rear brakes rebuilt and cleaned up, along with the torn axle boot replaced.

[caffeine]

Well lower octane would only happen under vacuum, not boost, and if you are using a breather to draw in the air then boosting the crankcase shouldn't be possible, at the expense of a boost leak if the check valve failed.

But like mentioned, there are bonuses to having vacuum in the crankcase under boost, so at the expense of simplicity there are more advantages to a vacuum pump or slashcut.

[TGP37]

Hmm is there a reason people don't just run a check valve to the intake? Lots of factory boosted cars seem to be setup that way.

I'm sure there is a way as you said. Though avoiding the complications, the black soot in the intake, lower octane from the oil/gas mixture, if the check valve fails then there is boost in the crank case.......


Eric,
I went cat free and decided to get a high flow cat. I like the sound much better with the cat, not as raspy. Then I don't have to f#ck w/ emissions testing and the o2 codes.

Wasn't too bad though, you might like the cat free sound. I thought about putting an extra resonator in place of the cat, help with rasp.


I can tell you the pump will work better then the slash cuts, by a large margin. With the pump, there is soo much more benefit beyond crankcase ventilation. Like extra power, better turbo oil sealing (vac travels up oil drain line), better ring seal, less oil contamination, it goes on.

[ericjon262]

Hmm is there a reason people don't just run a check valve to the intake? Lots of factory boosted cars seem to be setup that way.

I want to vent the crankcase, it helps with performance, and oil draining from the turbo.

found the wheels I want to go with...

[caffeine]

Hmm is there a reason people don't just run a check valve to the intake? Lots of factory boosted cars seem to be setup that way.

[ericjon262]

I was just going to put a V band on the inlet and swap is out with a straight pipe when I need to go silly fast.

my car won't have a cat converter. I may still run the slashcuts, I don't know... I'm researching the crank evac pumps now to see what will work best.

[TGP37]

The turbo will help muffle some. I use flowmaster 40's and it's not too loud at all. Though you have much less exhaust pipe to dampen, Fiero benefit.

About the PCV, don't recycle into the intake as the oil/air mix has a lower octane....not good for turbo. I dump past the O2's and before the catalytic into the exhaust.

Slash cut

A version w/ measurements


It seems the ideal feed pipe that evacuates the blowby should be 0.5"D (This I never knew until now....looks like I have an upgrade to make)

I do plan to use a catch can, for obvious reasons.

Though a powered vacuum to the crankcase can yield extra power, worth it if you go that route.




edit: You could have quiet mufflers then have a valve open to free pipe for performance driving. Some are electronic, flip a switch between quiet/loud and fast.

[ericjon262]

my drain line in the oil pan is bigger than 1/2". I need the tap for the LIM. also, NPT threads have a taper too.

I do need to work out the PCV system still, that's something that I hadn't put alot of thought into. I was going to do slashcuts in the exhaust, but that'll throw off o2 sensor readings. I'm considering getting an electric "smog" pump and modding it into a vacuum pump to pull a vacuum on the crankcase. I saw a write up on it ages ago, of coarse now that I need it I can't find it...

I'm starting to think about mufflers alot now, I'd rather not be that guy who wakes up all the neighbors... think a hooker aerochamber would work well on a turbo car?

[TGP37]

I thought so, it looked like it. looks like I'm in the market for a 1/2" NPT tap now...

-AN threads are tapered unlike NPT. I used -8AN (essentially 1/2" but tapered) allowing control over how far in the adapter can thread. Since the braided SS lines I had used -AN, it worked out.

Or you could weld it to the pan. 1/2" aluminum bungs aren't expensive as taps.



Standard works just as well, just not tapered. Which ever, just tossing that out there for ya.

For a fitting to run to my PCV breather.

Since you're running a MAF you might want to run a fitting from that valve cover to pre-turbo, post-MAF, depending on how you're routing the PCV system.

Either way the stock breather tube probably isn't useable and its easy to just tap the valve cover and install a hose fitting to run it wherever you want.

I just ran a line from the valve cover to the exhaust after the O2's. I tried other methods and this seemed to work best for me. With out it, exhaust was smokey. Tricky ventilating the crankcase (and do it effectively) with boost on a NA block.

[caffeine]

For a fitting to run to my PCV breather.

Since you're running a MAF you might want to run a fitting from that valve cover to pre-turbo, post-MAF, depending on how you're routing the PCV system.

Either way the stock breather tube probably isn't useable and its easy to just tap the valve cover and install a hose fitting to run it wherever you want.