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I didn't make that one.
Assuming yours is LHD, it'll be a PITA though
Originally Posted by Northern porker
Having a few available stocking problems. One of the dealers has offered me a Borg Worner 7670 with a 1.01 housing T4 twin scroll housing. He is stating this is a very similar turbo. Isthis the case or should I stick with the GTX3576R gen 2 T3 twin scroll 1.01 housing? If the Garrett is the one to go for I would rather wait and get the best turbo for the job. The only other benefit with the Borg turbo is that my fabricator would prepare the T4 housing for the available space as it’s quite tight as you are aware.
EFR7670 is a similar size to a gtx30/35 76R but they're huge in size.
Rod (Thingo) ran the largest EFR on his race car so i think he should chime in on his thoughts.
One of the dealers has offered me a Borg Worner 7670 with a 1.01 housing T4 twin scroll housing.
EFR turbos offer a packaging advantage when used with a turbine housing with the integrated wastegate. This should simplify the exhaust layout and free some room and weight around the clutch bellhousing where the single wastegate usually sits on a standard-ish engine. On paper the 7670 seems to compare well with the GTX3576R (Gen 1). Mitsubishi EVO folks seem to report that the EFR spools a little better, but it is a more expensive turbo, even when purchased without a "wastegated" turbine housing.
From what I can remember from the published drawings, the center housing on the EFR turbo uses the same bolt offset as the standard KKK turbo, which means that it should fit right away a standard 944 turbo mount, though that does not mean that some grinding work may not be needed to make room for a turbo that is physically larger than a standard KKK.
There does not seem to be many people on this board who have installed EFR turbos apart from a handful with widely/wildly modified all-out race engines with lots of custom work, and it does not quite sound like you are quite in this boat.
A twin scroll set up dissociates reverting exhaust pulses so in any case should allow any top end to flow better under any load and at any rpm than any single scroll set up. Since you seem to be starting from a blank sheet of paper it is perhaps worth considering an EFR over a Garrett turbo, while others like me who already have put some work into fitting a GT turbo may see too little gain for the investment required. I would go for an EFR over a GTX Gen 2 in any way, or keep the budget lower and use a GTX Gen 1.
The only Gen 2 GTX turbo that may be of any interest is the GTX3584RS as it uses a new turbine wheel design, while the other Gen 2 turbos carry on with the same old GT turbine also used on the GTX Gen 1 turbos. The GTX3584RS is good for 1000 hp though, so certainly oversized for real-world engines. The smaller G25 seems to use the same turbine wheel design, but the turbine flow chart shows it is in my opinion too small a turbo for a 3L 944/968 turbo engine, especially a 16V one.
EFR turbos offer a packaging advantage when used with a turbine housing with the integrated wastegate. This should simplify the exhaust layout and free some room and weight around the clutch bellhousing where the single wastegate usually sits on a standard-ish engine. On paper the 7670 seems to compare well with the GTX3576R (Gen 1). Mitsubishi EVO folks seem to report that the EFR spools a little better, but it is a more expensive turbo, even when purchased without a "wastegated" turbine housing.
From what I can remember from the published drawings, the center housing on the EFR turbo uses the same bolt offset as the standard KKK turbo, which means that it should fit right away a standard 944 turbo mount, though that does not mean that some grinding work may not be needed to make room for a turbo that is physically larger than a standard KKK.
There does not seem to be many people on this board who have installed EFR turbos apart from a handful with widely/wildly modified all-out race engines with lots of custom work, and it does not quite sound like you are quite in this boat.
A twin scroll set up dissociates reverting exhaust pulses so in any case should allow any top end to flow better under any load and at any rpm than any single scroll set up. Since you seem to be starting from a blank sheet of paper it is perhaps worth considering an EFR over a Garrett turbo, while others like me who already have put some work into fitting a GT turbo may see too little gain for the investment required. I would go for an EFR over a GTX Gen 2 in any way, or keep the budget lower and use a GTX Gen 1.
The only Gen 2 GTX turbo that may be of any interest is the GTX3584RS as it uses a new turbine wheel design, while the other Gen 2 turbos carry on with the same old GT turbine alos used on the GTX Gen 1 turbos. The GTX3584RS is good for 1000 hp though, so certainly oversized for real-world engines. The smaller G25 seems to use the same turbine wheel design, but the turbine flow chart shows it is in my opinion too small a turbo for a 3L 944/968 turbo engine, especially a 16V one.
I think the 7670 would probably go well, but I don’t know if you could fit the iwg version in it’s s very long. We used the 9180 on the stock engine and it was great but that is a big turbo, once you start asking that much from the stock block there is a lot of things you have to start thinking about, the 7670 will be more responsive than the 3576, make similar power. I’m a big fan of the efr turbos. Maybe the 8374 but I think that would be a tight fit.
Ebay from China £200 they are now selling same but with 75mm TB and fuel rail for the same money. It’s not billet but it’s ok. Once welded up I will fill the whole thing with water and see what the volume is. It will be at least 4L I think it’s bigger than it looks.
I think the 7670 would probably go well, but I don’t know if you could fit the iwg version in it’s s very long. We used the 9180 on the stock engine and it was great but that is a big turbo, once you start asking that much from the stock block there is a lot of things you have to start thinking about, the 7670 will be more responsive than the 3576, make similar power. I’m a big fan of the efr turbos. Maybe the 8374 but I think that would be a tight fit.
With TS housing and the IWG of the EFR does it work for both cross over pipes. I like the idea of quicker spool. Again great info thanks
If you can get the iwg to fit it would make for a tidy install, but I can’t tell you if it would fit. A twin scroll 7670 should be very responsive with plenty of power everywhere.
If you can get the iwg to fit it would make for a tidy install, but I can’t tell you if it would fit. A twin scroll 7670 should be very responsive with plenty of power everywhere.
7670 it is then probably go with external WG just to make sure it fits (turbosmart 40 mm compgates in traditional placement).
Thanks for everybody’s comments and opinions I haven’t posted very much in the past as I have not used my cars in the last 5 years or so but I have followed various related threads and know I have had a wealth of experience helping make this decision.
I will post the progress of this project for anyone who is interested although I don’t think I will be doing anything that hasn’t been done before.
All ready for engine build just need to decide on rod bearings thinking ACL does anybody have any experience with these or similar. If anybody has drawings or dimensions for rod machining it would be appreciated. Block and head back from machining people all looks good.
I asked ACL about our cars a couple months ago regarding their race main and rod bearings and they said they have plans in the works for them and they are about a year out from supplying them for our cars.
10-30-2018, 11:23 PM
