Hello everyone my friend is about to get a 85 6.9 and he wants to add some performance to it. One of the many the many things he wants to do is add twin holset turbos. I think that would be about 60 psi if he put on a head stud kit from dps would it work?
it would work on a powerstroke, something that can handle that much boost.
but on these idi's... first ive never heard of a twin turbo set up on an idi.
second with the higher compression on them, 60 psi would be somewhere near imposible.
the highest boost numbers ive seen and a 6.9 or 7.3 idi are mid 20's (daves)
and thats after extensive work to his 6.9.
in my opinion if your friend wants a performance diesel, get something that would be easier to get that much more power out of.
Simply fitting the turbos (and related piping) would be a challenge. If you drop the compression ratio, you could probably run some high numbers like that, but to drop that much compression will cause cold start and serious economy issues.
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1986 F250HD Ex cab Fresh built up 6.9L diesel Lariat AC leather seats power everything w/full cluster, sterling rear 3.08LS gears, E4OD trans, ram intake ATS 088 turbo
1986 F150 Ex cab Lariat rollercam 5.0L on LPG AOD trans 3.55 gears 390 000Ks
i told him that that was probably too much psi for that high of a compression, not to mentioned they were never designed for a turbo. However i have a 93 7.3 and was considering a single holset, I'm not as ambitous, i think that with a head stud kit it might work but i dont want to tear it up ill probably have the moter out wwhen i do this but I'm not doing a rebuild, yet.
Ok first off wich holsets are you talking about? they make them in many different verieties and alot of them would not put out much boost with the exaust flow of theres engines. 60psi on the stock 21.5 to 1 cr would be an insanly high efective compresion ratio. But If you guys like the trucks, have money and would like to make a preformace truck it is definatly possible. Get head studs heads with built in firerings milled down pistons, and a custom IP and injectors. I'd also replace the rods and use ARP rod bolts if availible and have the governor set at 4000 rpm with some heavy duty valve springs.
Twins are possible I've seen a powerstroke with three turbos you could definately fit two on one of these but a single turbo could also be made to put out high boost #.
So how fast can you aford to go?
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94 F350 Crew Cab Long bed 4X4 7.3L IDI Factory Turbo, AKA The Land Yacht. E4OD, 4.10 posi. Getting further from stock with 35 inch BFG alterains on 16 inch micky's, straight pipe, Triple A-piller pod with pyro, boost, modifyed stock oil presure gauge, tc lock light&switch
22.5 to 1 base compression ratio with 60 PSI boost would have an effective compression ratio of 114.33 to 1.
A Power Stroke engine with an 18 to 1 compression ratio would only be 91.46 to 1 with 60 PSI boost.
Right now my compression ratio is 20.25 to 1, with 25 PSI boost my effective compression ratio is 54.68 to 1.
At 30 PSI that increases my effective compression ratio to 61.57 to 1.
A Power Stroke running 30 PSI has an effective compression ratio of 54.73 to 1.
There is a limit as to how low you can go with the compression ratio of an IDI, starting will be a big issue at 18 to 1 or lower.
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86 F250 HD 6.9 IDI ATS turbo "not exactly" stock 4x4 T19 BW1345 3.55LS both ends D60 front, 10.25" Sterling rear, ram air, dual stacks.
I doubt it would hold together long at 60 psi, even with studs, and as far as studs, go with the ARP head studs, There has been a rash of failures lately on the DPS head studs and the guy has yet to respond to a single one of the people who spent hundreds of their hard earned dollars with him on his defective studs, He's left them all holding the bag.
There is also an ARP option for 7.3 head studs .
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'92 F350 CC Dually, 7.3 Ats Turbo, 4" exhaust, Custom Rodney Red aluminum radiator, Zf5, 4.10 ,Western Hauler bed, Air seat, Bilsteins.
Yes you do might be able to get away with studs and heads with built in firerings or an oringed block.
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94 F350 Crew Cab Long bed 4X4 7.3L IDI Factory Turbo, AKA The Land Yacht. E4OD, 4.10 posi. Getting further from stock with 35 inch BFG alterains on 16 inch micky's, straight pipe, Triple A-piller pod with pyro, boost, modifyed stock oil presure gauge, tc lock light&switch
Lariat AC leather seats power everything w/full cluster, sterling rear 3.08LS gears, E4OD trans, ram intake ATS 088 turbo
