If EFR budget...
07-02-2014, 01:01 PM
#1
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If EFR budget...
A two part query for you:
If you had the budget for a efr 7163 and a chassis waiting on power would you consider anything else (gtx, comp triple ball bearing, ect)?
Why?
I have the chassis, powerplant to support, and have done my research but need to get a new Mani built to insert said turbo and am looking for some other opinions. Thanks guys.
If you had the budget for a efr 7163 and a chassis waiting on power would you consider anything else (gtx, comp triple ball bearing, ect)?
Why?
I have the chassis, powerplant to support, and have done my research but need to get a new Mani built to insert said turbo and am looking for some other opinions. Thanks guys.
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07-02-2014, 01:04 PM
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Not really. Maybe re-evaluate your power goals and decide whether you really want/need 500whp, and if you can live with 450, look at a 6758 to improve low-end power.
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07-02-2014, 02:30 PM
#3
EDIT: I also understand that this is a full throttle run and does not provide part throttle or transient response data but my throttle only has 2 positions anyway
EDIT 2: Not a built bp but the behavioral characteristics are still relevant.
I ran a GT2860RS and GT2871R with a Tial turbine housing and external gate on my car (2.0Lt on E85) before moving to the EFR turbos.
Car is now running an EFR7163 after initially having the EFR6758. The 6785 out flowed the GT2817R, had better spool (boost threshold) and better transient response than the GT8271. The 7163 was around the same boost threshold but way outflowed it and has better transients. It was making around 325kw ATW's before we ran out of injector so it might have a little more in it but I think the turbine housing is going to start choking it off pretty soon.
Car is now running an EFR7163 after initially having the EFR6758. The 6785 out flowed the GT2817R, had better spool (boost threshold) and better transient response than the GT8271. The 7163 was around the same boost threshold but way outflowed it and has better transients. It was making around 325kw ATW's before we ran out of injector so it might have a little more in it but I think the turbine housing is going to start choking it off pretty soon.
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07-03-2014, 03:09 AM
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So the goal is 300 HP with low boost but also to have the ability to run a higher pressure and not be limited by the turbo or fuel. I feel I have the supporting items to do that before going with a new engine management system and a vvt head (these are the next steps for me).
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07-03-2014, 03:53 PM
#11
Along these lines... I already have a Precision 4828 which is supposedly a potato with some better parts. It is on a BEGI cast manifold. Would it make sense to move the precision turbo over to an EFR compatable manifold and fab a downpipe until I can afford to build the motor (hopefully get better spool out of it) or should I just hold off and do the EFR at the same time as the manifold/downpipe? I am at about 230whp now but I feel like I am not hitting 10psi boost until 4,300 rpm or so.
(my spool data
https://www.miataturbo.net/diy-turbo...2/#post1140285
Current downpipe is BEGI non-divorced gases pipe that exits to 2.5" and it continues 2.5" to the muffler at which point it exits at 3". I am holding off upgrading the mid-pipe until I also do the downpipe...
If my goal is to improve spool and reduce the amount of parts bought twice, where is the smart money?
Given the following future upgrades: build engine with forged rods, EFR 6758 or 6258, EFR compatable manfold, 3" turbo to tailpipe.
Also, consider that the block is stock for now.
(my spool data
https://www.miataturbo.net/diy-turbo...2/#post1140285
Current downpipe is BEGI non-divorced gases pipe that exits to 2.5" and it continues 2.5" to the muffler at which point it exits at 3". I am holding off upgrading the mid-pipe until I also do the downpipe...
If my goal is to improve spool and reduce the amount of parts bought twice, where is the smart money?
Given the following future upgrades: build engine with forged rods, EFR 6758 or 6258, EFR compatable manfold, 3" turbo to tailpipe.
Also, consider that the block is stock for now.
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07-03-2014, 04:23 PM
#13
To isolate one question I asked above, can I mount my current turbo on a tubular manifold designed for an EFR? Obviously it would be a different downpipe than an EFR but if I am going to replace something, i'd rather it be the downpipe. Heck, I might even be able to modify the downpipe to make it work, but then that might be almost as much money as a brand new one?
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07-03-2014, 06:24 PM
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One point here,
Never use a dynapack dyno to show differences in spool up of different turbos. You can program the ramp rate of the dynapack which allows you to set it to increase RPM's from 2000 to 4000 very slowly, and this will tend to make a large turbo spool at a much lower RPM than it would if RPM's increased at a faster rate. I'm not sure if other load cell dyno's can do this but I know that the dynapack can.
Keith
Never use a dynapack dyno to show differences in spool up of different turbos. You can program the ramp rate of the dynapack which allows you to set it to increase RPM's from 2000 to 4000 very slowly, and this will tend to make a large turbo spool at a much lower RPM than it would if RPM's increased at a faster rate. I'm not sure if other load cell dyno's can do this but I know that the dynapack can.
Keith
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07-03-2014, 09:34 PM
#17
Although I agree that making sure 500rwhp is something you are actually looking for I would like to add that the testing I have seen of the two turbo's back to back show that the 7163 out performs the 6758 in almost every way because it is a gen 2 design.
EDIT: I also understand that this is a full throttle run and does not provide part throttle or transient response data but my throttle only has 2 positions anyway
EDIT 2: Not a built bp but the behavioral characteristics are still relevant.
EDIT: I also understand that this is a full throttle run and does not provide part throttle or transient response data but my throttle only has 2 positions anyway
EDIT 2: Not a built bp but the behavioral characteristics are still relevant.
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