So the garret ball bearing turbo on my lb7 seems to have high drive pressure. 65-70 psi on 32-34 pounds of boost. It has 68mm compressor inducer on the 72 mm turbine, which i'm finding out is stock lly turbine size. Anybody else have drive/boost ratios on s366s, variable turbos, or s400s. Thanks
Garret gt 3788r drive pressure
- Thread starter 03blkdmax
- Start date
What exhaust housing? Gated? That seems to be where mine runs with the .89 housing and the gate cinched down. Granted this is in my mismatched compound setup so sorta apples to oranges. There is a big power increase with a loosened gate, even before the large charger starts moving.
68mm compressor inducer????
Stock common was 63.5 same as a 4088r which had a bigger 77mm turbine wheel
Stock common was 63.5 same as a 4088r which had a bigger 77mm turbine wheel
Yeah i know. Mine was worked over and fitted with that wheel, we measured it, yeah i wish it had the 4088 turbine, i think the compressor is that big that the turbine doesnt have enough power to turn it without making high back pressure, it spools pretty good tho
My gt4088r has a bored out gt378r .83 waste gated T3 housing.. got it gated to 32psi.. haven't pushed it farther on my LMM.
That 68 may be too large as I can get a good 1:1 up to around 32psi, with the large charger barely moving the gauge. From there up the drive starts increasing drastically. Who did the 68 upgrade? Is it just a bored out original compressor housing with the 2.5" discharge? I wouldn't mind trying to get a little more airflow through mine. I feel like that is the choking point for the large charger.
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Got it from the tial sport stand at schied diesel.. so apparently they sell and modify garrets. Yeah the discharge fit the stock lb7 boost tube. Give tial a call, see what they say. Once ur big charger starts moving air, it d be ur exhaust wheel and housing restricting right?
The exhaust side shouldn't be the restriction as once the small charger gets up to its operating speed the external gate pops open and directs the rest of the drive to the large charger. However if I want to keep boost to drive 1:1 then the large charger ends up having a higher than 2:1 boost pressure ratio. Aka like 35 from the atmosphere with like 60psi total. Makes me think the compressor housing on the GT cannot flow much more. Again, mismatched setup Haha.