Top End Rebuild and Turbo Project underway

[polizei]

I think I found the issue last night. The plumbing leading to the air filter in the engine compartment was so tight up against the #1 upper spark plug that it kept pulling the plug wire out. I tore out all of that plumbing and ran the filter in the rear wheel well. Took her out for a drive and WHAT A DIFFERENCE! It seriously HAULS! I was kind of nervous to explore the power last night since I'm still in the break-in period with the car and the fuel is still not dialed in correclty (got an LM-2 to replace my faulty LM-1), but I could definitely tell there was there was a huge difference.

After having blown off the rubber elbow connecting the AFM to the throttle body several times this past weekend, we decided to use rivets to secure the elbow to the AFM collar. It seemed to work well for a while, but it blew it off again and this time tearing through the rubber. Unless you guys have a suggestion, I'm planning to get one custom made as there needs to be a vacuum connection going to the Venturi Tube (brake booster) and for idle.

Ben, I took a picture of the boost gauge connection to the brake booster, but I forgot my camera card reader today. I'll get it up here tonight.

Thanks everyone for your help! This has been such an enormous and enjoyable learning experience for me. I would have NEVER attempted this without your advice, direction, and support. You guys seriously rock. If any of you find yourselves in southeast PA, look me up and I'll let you take my car for a spin. Thank you!

[WERK I]

That's excellent! You must feel a tremendous amount of accomplishment.

[hobieboy]

Originally Posted by polizei

After having blown off the rubber elbow connecting the AFM to the throttle body several times this past weekend, we decided to use rivets to secure the elbow to the AFM collar. It seemed to work well for a while, but it blew it off again and this time tearing through the rubber. Unless you guys have a suggestion, I'm planning to get one custom made as there needs to be a vacuum connection going to the Venturi Tube (brake booster) and for idle.

Andy, you can get a tight radius 90 deg aluminum elbow then use 2 silicone couplers to secure them. Is the AFM "hanging" there or is there a support to secure it? That may be part of the problem?

BTW - congrats on sorting out the major issues

[jbrinkley]

that's good to hear. congratulations

[EPorsche]

Could you do a write up (summary) of parts (in a list) and pics so others (like me) could have a good platform to start from instead of reinventing the wheel.

[911st]

What about making it a suck through instead of a blow through? This will be a better soulition if you decide to run at higher boost levels when you get your intercooler. Then you will not have to worry about blowing up the AFM.

[polizei]

Thank you all for your kind words.

Originally Posted by hobieboy

Andy, you can get a tight radius 90 deg aluminum elbow then use 2 silicone couplers to secure them. Is the AFM "hanging" there or is there a support to secure it? That may be part of the problem?

The trouble is that I would need to plumb some connections off of the elbow for the ICV and brake booster - I'm just not sure how to do that :-/ The AFM is secured on both its sides. I'm guessing that the rubber material is so flimsy that caves in from all the pressure.

Originally Posted by EPorsche

Could you do a write up (summary) of parts (in a list) and pics so others (like me) could have a good platform to start from instead of reinventing the wheel.

Yes, I will put something together.

Originally Posted by 911st

What about making it a suck through instead of a blow through? This will be a better soulition if you decide to run at higher boost levels when you get your intercooler. Then you will not have to worry about blowing up the AFM.

That's an excellent idea. Would the computer tripped up by the fact that it's receiving more air than it's expecting, since there's more flow after the turbo than before? The only other issue I see with this is lack of space, but I'm sure it can be done.

Ben, here are some pictures of how I've connected the boost gauge to the brake booster:

[WERK I]

I think the "suck through" idea sounds great as well. This board rocks!!
Maybe you can pass the idea through Todd to see what he thinks? The only question I would have is when the throttle is closed under boost conditions, i.e. full throttle conditions under boost and changing gears. I wonder if there would have to be some sort of recirculation of boost, like in the 930 CIS systems.

[911st]

Couple of things on a suck through.

This is a more typical way to set up a motor. New car makers do not to a blow through.

With the Carrera 3.2 the AFM gets pegged at around 180 rwhp of air flow and mostly is not used any further to determin fueling so it is the RPM table on the chip and the raising rate fuel pressure reg that determines your fueling.

The only time there is more CFM measured at the AFM between the two should be when you let off the throttle and the blow off valve opens and vents to atmosphere. With EFI the fueling is mostly stopped when the throttle is lifted so this should not be an issue. Worst case you will spit a little flame out the exaust.

Check w Todd about this as he is the expert. It should not make much difference.

If you want he can convert you to a boost sensing system which takes the AFM out of the system altogether and you get a program to map your own chip.

[mb911]

the picture looks right to me I would check to see what your brake booster line is connected to in the engine bay

[WERK I]

Could there be a check valve in that line in the engine bay?

[polizei]

Originally Posted by mb911

the picture looks right to me I would check to see what your brake booster line is connected to in the engine bay

Is the line that is T'd into the boost gauge line, the same line that would be running to the engine bay?

Originally Posted by WERK-I

Could there be a check valve in that line in the engine bay?

Jerry mentioned there is one as well. Wouldn't a check valve prevent positive pressure from going to the brake booster and in turn prevent a boost reading?

Originally Posted by 911st

Couple of things on a suck through.

This is a more typical way to set up a motor. New car makers do not to a blow through.

With the Carrera 3.2 the AFM gets pegged at around 180 rwhp of air flow and mostly is not used any further to determin fueling so it is the RPM table on the chip and the raising rate fuel pressure reg that determines your fueling.

The only time there is more CFM measured at the AFM between the two should be when you let off the throttle and the blow off valve opens and vents to atmosphere. With EFI the fueling is mostly stopped when the throttle is lifted so this should not be an issue. Worst case you will spit a little flame out the exaust.

Check w Todd about this as he is the expert. It should not make much difference.

If you want he can convert you to a boost sensing system which takes the AFM out of the system altogether and you get a program to map your own chip.

Excellent information. I've sent an email to Todd to verify whether the suck through method would pose any issues and to get some figures on how much his MAP solution costs.

[jbrinkley]

don't know if this helps, but here it is

[WERK I]

Yes, if there were a check valve, the boost gauge would register vacuum, if it is so designed. If you disconnect the line from the boost guage, and hook up a vacuum gauge while the engine is running, the check valve theory might prove true.

[polizei]

Originally Posted by WERK-I

Yes, if there were a check valve, the boost gauge would register vacuum, if it is so designed. If you disconnect the line from the boost guage, and hook up a vacuum gauge while the engine is running, the check valve theory might prove true.

Given Jerry's diagram above and the fact that my boost gauge also measures vacuum, I guess it's safe to say there is a check valve. Perhaps the best thing to do at this point is permanently run the boost gauge off of a line running directly to the intake manifold.

[WERK I]

.....or move the check valve to the other side of the "T" to the brake booster side.

[polizei]

I asked Todd if there would be a problem with running the AFM on the inlet side of the turbo (between the air filter and the turbo inlet). Here's his response:

*****
Yes. The metering is completely different. On the inlet side, it measures cfm, a lot of it. On the pressure side it also measures cfm, but compressed due to boost and the fpr modifies the signal to compensate for boost. On the inlet side, it’s pegged at about 3500rpm’s and there’s no metering left.
*****

He also mentioned this concerning the AFM being destroyed by boost:

*****
It’s typically more of a problem when you lift off of the throttle and the boost spike pops it. Run a really good blow off valve and you won’t have that problem. I’ve run 1.4 bar through them
*****

And here's the info on his MAP ECU to ditch the AFM:

*****
Our pressure sensing system is $2211.72 for the conversion to the ecu, software, tps/adapter, iat, etc. We use an unused a/d channel in the ecu for the pressure transducer, mount it inside the ecu, route the rest of the circuitry, and then use the tps/iat for other compensations. You get a copy of our Motronics calibrator with it that’s normally $995.00 by itself.
*****

[WERK I]

Here's the check valve the 930's use, item 29, part # 191-611-933 F

[polizei]

Originally Posted by EPorsche

Could you do a write up (summary) of parts (in a list) and pics so others (like me) could have a good platform to start from instead of reinventing the wheel.

Engine:
ARP Rod Bolts - M&K Exhaust
Supertec Head Studs - M&K Exhaust
Mahle 8.0:1 Pistons & 3.3 L Cylinders - Road & Race
Valve Job and Heads drilled for Twin Plugs - Supertec
Gasket kit - Pelican Parts

Twin Plug:
964/993 Twin Plug Distributor - Road & Race
Caps & Rotors - Road & Race
Magnecor Ignition wires - Magnecor (order stock '84-89 Carrera wires for upper and '89-94 Carrera length wires for lowers with '84-89 connectors)
Andial Splitter - Pelican Used Parts Board
Lower Plug Holders - Supertec
Extra Coil - Road & Race
Lower Valve Covers drilled - Pelican User cgarr - Craig
Double Coil bracket (welded) - Road & Race
(check out this thread for issues I ran into: Twin plug install question)

Turbo, Exhaust, Intake:
Precision SC6162SPR - TD Autowerkes
Tial 46mm Wastegate - Pelican Used Parts Board (930gt-40r)
Tial 50mm BOV - M&K Exhaust
Aluminum Intake/Charge plumbing- Local race shop
Silicone couplers, bends, elbows - http://www.siliconeintakes.com/
930 J pipe turbo manifold (modified to get around twin plug dizzy) - Supertec
Muffler/Exhaust - M&K Exhaust
Brackets for charge pipe - Nate Dog Creations (local fabrication shop)
Weld collar onto AFM to secure elbow to TB - Nate Dog Creations
.7 BAR wastegate spring - M&K Exhaust
AFM flange - M&K Exhaust
ECU programmed for turbo and twin plugs - Protomotive
K&N Air filter RX-3990-1 - Summit Racing

Oil Lines/Fittings:
Replacement hard oil Line to bottom of case - Elephant Racing
Replacement hard oil line from above line to thermostat - Elephant Racing
3 foot 10mm banjo end -3 to -4 oil line for turbo oil feed - Protomotive
2 feet of -10 stainless steel oil line for turbo return - http://www.batinc.net/ (check page 4 of this thread)
Fittings - BAT Inc and Home Depot for brass fittings

Fuel:
BEGI 2025 Rising Rate Fuel Pressure Regulator - Ebay
2 feet of -6 stainless steel line - BAT Inc
Fittings - BAT Inc (check page 4 of this thread)
Check Valve - http://www.bellengineering.net/

Gauges:
NHS (VDO Clock replacement) boost gauge And tubing kit - M&K Exhaust
Innovate LM-2 Air Fuel Ratio Gauge - Ebay
Fuel Pressure Gauge - http://www.bellengineering.net/
Air Temperature Gauge - Andial

Miscellaneous:
Spring Centered Clutch - Pelican User Parts Board
Pressure Plate - Pelican User Parts Board
Clutch Throwout Bearing - Pelican User Parts Board
Updated G50 Clutch Release Fork - Pelican User Parts Board
Reference & RPM sensors - Pelican
Cylinder Head Temp Sensor - Pelican
$500 in extra stuff - paint, carb cleaner, brake cleaner, wires, tools ... stuff

Let me know what pics you'd like to see, and I'll post them. Also let me know if i've left anything out. Also check out these threads if you're converting from a narrow body Carrera, and you're considering fitting an intercooler:

Intercooler in stock Carrera Whale Tail?
Intercooler vs. No Intercooler

I'm running no IC currently, but I'm planning to run water injection by next summer.

[NathanUK]

RE: The checkvalve on the brake booster, no. 29 in the pic...

Stephen of IA sells a gauge kit to replace the clock and it comes with a special checkvalve to replace the stock one. It has another port to connect some small tubing to the new gauge so you don't have to modify/hack the car too much. I'm guessing NHS also does it.