Is the EFR6258 too much for stock engine?
#41
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
There's a pleasantness to having a very wide torque band which is there in my 540i, and which the 2554 was better at than the 2560.
And unless the same person drives the 2 turbos then the only way to compare 2 different setups is through datalogs.
#42
Former Vendor
![](/mt2011/images_td/ranks/supporter1.gif)
iTrader: (31)
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 15,442
Total Cats: 2,103
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
I've driven both turbos. My subjective opinion is that the EFR responds better than every Garrett setup I've driven, including my old BP4W/2554R setup. I agree that the 2560R is a softer turbo, and the 2860RS is softer again (IMO that turbo is too big for a 1.6 and as large as I would ever go for a 1.8 street car, having owned a 2871R). The 6258's spool was as good or better than my 2554R setup was, and the transient response was better.
Last edited by Savington; 08-28-2014 at 01:12 PM.
#50
Senior Member
iTrader: (3)
Join Date: Dec 2007
Location: Seven Valleys, PA
Posts: 638
Total Cats: 11
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
The point is that EFR turbo does not belong on a stock engine...
#51
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
#54
Former Vendor
![](/mt2011/images_td/ranks/supporter1.gif)
iTrader: (31)
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 15,442
Total Cats: 2,103
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
Then your EMS4 basemap timing is more aggressive than I thought. This was on a minimally pre-loaded 7psi actuator it creeped to 10psi at peak torque and more or less on your timing and vvt maps (putting a car with electrical problems the dyno is some expensive troubleshooting), lol. I think 8psi on the 6258 or 6758 EFR is going to be worth more than 200ftlbs with a more aggressive timing map.
#57
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
This thread actually had the best actual comparison data I've seen. Are there any others?
https://www.miataturbo.net/diy-turbo...cussion-79576/
https://www.miataturbo.net/diy-turbo...cussion-79576/
#59
Elite Member
iTrader: (37)
Join Date: Apr 2010
Location: Very NorCal
Posts: 10,448
Total Cats: 1,900
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
I'm currently sitting on a 6258 so I've had a good time following this thread.
This sums up my thinking exactly. I'm going to try my best not to do my install until there is a built motor between the frame rails. I have no doubt that someone with careful planning, experience and knowledge of how these systems work would be able to keep things "stock block" compliant, but I'm not that person. I see no reason to run a baller manifold & $$$ turbo that'll do 44lbs/min at something silly like 5~6psi to preserve the stock block.
If all you want is 200/200 and epic spool, go buy a FMII & 2554.
If all you want is 200/200 and epic spool, go buy a FMII & 2554.
#60
Junior Member
Thread Starter
Join Date: Jan 2014
Location: Port Saint Lucie,FL
Posts: 476
Total Cats: 12
![Default](https://www.miataturbo.net/images/icons/icon1.gif)
I'm currently sitting on a 6258 so I've had a good time following this thread.
This sums up my thinking exactly. I'm going to try my best not to do my install until there is a built motor between the frame rails. I have no doubt that someone with careful planning, experience and knowledge of how these systems work would be able to keep things "stock block" compliant, but I'm not that person. I see no reason to run a baller manifold & $$$ turbo that'll do 44lbs/min at something silly like 5~6psi to preserve the stock block.
If all you want is 200/200 and epic spool, go buy a FMII & 2554.
This sums up my thinking exactly. I'm going to try my best not to do my install until there is a built motor between the frame rails. I have no doubt that someone with careful planning, experience and knowledge of how these systems work would be able to keep things "stock block" compliant, but I'm not that person. I see no reason to run a baller manifold & $$$ turbo that'll do 44lbs/min at something silly like 5~6psi to preserve the stock block.
If all you want is 200/200 and epic spool, go buy a FMII & 2554.
But you are right, no sense in attempting to tame that beast for the sake of a stock block...(and probably failing at that, too.)
It is kinda lame that the FMII kit is gonna cost me more tho, that's the part I don't like.