Turbocharger/Exhaust - Modifications
83porsche02Subject: Turbocharger
Part Identifier 2130
Applies To 924 Turbo
All years
Group
21
Key Points
Modifications of turbocharger, exhaust manifold, and exhaust system
C
Number
83-03
November 2, 1983
Modifications have been made to the turbocharger, exhaust manifold, and exhaust assembly of the 924 Turbo models.
FIGURE 1:
Turbocharger
Collar bolts and spacers are now used to attach the turbocharger exhaust inlet to the exhaust manifold on 81/82 models. These bolts and spacers should be used when repairing 1980 models. The studs on the exhaust inlet of the old turbocharger must be removed. (Fig. 1)
For replacements, only the newest version turbocharger is available (without studs on the exhaust inlet and with seal grooves on exhaust inlet and outlet).
In addition, the turbocharger has been thermally improved by internal modifications. The modified versions have been assigned new part numbers and version numbers.
Exhaust manifold
Exhaust manifold P/N 931.111.096.00 is now a valid replacement part for 1980 models. This manifold does not have studs on the turbocharger mounting flange. The intermediate ring is available separately. P/N 931.111.599.01. The old intermediate ring is spot welded in the manifold. The ring should be inspected whenever the turbocharger is removed. Remove a defective ring by grinding off the spot welds. The new intermediate ring does not require welding.
The wall thickness of the bypass pipe has been increased from 1.5 mm to 2.0 mm. P/N 931.123.033.04.
General repair instructions
Turbocharger malfunction (smoking ) may be the result of inadequate turbocharger venting. If smoking occurs, the breather system must be modified as described in Product Circulars, 83-01 and 83-02 Group 21. When repairing the turbocharger or replacing the system components, check the production dates of the turbocharger, exhaust manifold, and bypass line. Make replacements as necessary. When replacing turbocharger and manifold together, use installation kit P/N 000. 043. 018. 00 . This contains all mounting parts, seals, and gaskets.
FIGURE 2:
Exhaust manifold installation
If, because of close manufacturing tolerances, the exhaust manifold cannot be easily fitted to the cylinder head, chamfer the exhaust manifold intermediate rings (Fig. 2) and de-burr the cylinder head exhaust ports with a knife or similar tool.
Note Turbocharging system must be assembled without forcing pieces together.
Work sequence
- bolt turbocharger to turbocharger mounting bracket DO NOT REMOVE STUDS ON TURBOCHARGER
- loosen bolts on turbine retaining plate
- bolt turbocharger and mounting bracket to engine and exhaust manifold
- tighten bolts in sequence
FIGURE 3:
Tightening torques ( Fig. 3)
1 - collar bolts 50 N-m ( 36 ft lb ) hexagon nuts 35 N-m ( 25 ft lb ) 2 - hex head bolts 25 N-m ( 18 ft lb ) 3 - hex socket bolts 25 N-m ( 18 ft lb ) 4 - M8 nuts 25 N-m (18 ft lb) M6 nuts 12 N-m ( 8 ft lb )
Note Only specified, heat-proof mounting parts (studs, nuts, collar collar bolts and spacers) may be used.
Caution
When replacing turbocharger, change engine oil and oil filter.
Caution Do not install expansion seals and flat gaskets together.
Replace exhaust lead pipe (turbocharger to primary muffler or catalytic converter), if cracked. Install new holders at this time. Kit P/N 000. 043. 023. 00
FIGURE 4 - BYPASS VALVE HOLDER NOMENCLATURE:
1 - Clamp 2 - Holder 3 - Retainer 4 - Hex. head bolt M8 x 40 (two) 5 - Washer 8.8 (two)
FIGURE 5 - EXHAUST LINE HOLDER NOMENCLATURE:
6 - Holder 6a - Clamp 7 - Bolt 8 - Washer 13 9 - Nut M12 10 - Hex. head bolt M10 x 95 11 - Hex. head bolt M10 x 50 (two) 12 - Washer 10.5 (Three) 13 - Nut M10 (Three)
Bypass valve holder and Exhaust line holder installation
Work sequence
- disconnect battery
- remove starter
- remove Bypass valve (RM 924 Turbo, Group 21) Note If only new holders are being installed, exhaust pipe between turbocharger and final muffler does not need to be removed.
FIGURE 6:
- remove bolts a and b from clutch bell housing (Fig. 6)
^ make sure threads extend through bell housing
FIGURE 7:
^ tap threads with M12 x 1.75 mm tap if necessary
- install holder 6 with bolt 10 (Fig. 7)
- install bolt 7, threading from behind
- DO NOT TIGHTEN BOLTS
- remove old clamp and holder from transaxle
- install new clamp and holder
^ tighten upper bolt so that clamp can still be turned
^ holder is tightened with lower bolt after installation of Bypass valve
- remove old holder from Bypass valve and install new holder
- DO NOT TIGHTEN BOLTS
- install Bypass valve ( with exhaust pipe if replaced )
- DO NOT TIGHTEN NUTS
- bolt on shield above bypass line
- install bypass line with new gaskets
FIGURE 8:
- bolt clamp 6a to exhuast and bypass line holder (Fig. 8)
- tighten bolts 7 and 10
- tighten remaining bolts and nuts
- install starter
- connect battery