The ones who blew their motors on e85-- was that from bent rods or head gasket issues?
I'm thinking that with a built motor you wouldn't need to worry?
It was from broken rods due to way too much pressure.
I've heard of even built motors getting blown up because tuner got carried away with advancing timing/raising boost and just kept going due to not seeing knock til something gave.
Originally Posted by scottyd
Did you ever fix your boost sag issue?
I put in a 14psi wga and it helped a lot. I think there is still a TINY bit of boost sag past 6k but its minor and doesn't bother me at all.
Already have a dyno/shop lined up.
Going to call them most likely on monday to set up appointment.
Hopefully within a week or so they have some time available that will work with my schedule. I'll be doing my own tuning and on the dyno want to focus mainly on the timing map. Hopefully I can come out of there with over 300whp. If not no big deal but I see no reason at all why I shouldn't judging by other peoples setups/timing/boost/etc.
I'm on e85 and comparing to others even on pump gas with similar size turbos as me and all that it seems I'm about "average" timing wise. I've seen people with the same timing (in terms of peak timing @ boost and out of) maps (and quite a few with much more aggressive) on pump gas.
At peak boost I'm right around 16.5-17psi. It hits 14.8, slowly creeps up to 16.7, then slowly tapers to 14 by redline.
I'd like to hear your suggestions on improving this map (even before I go to the dyno).
I'm going to up the timing after 6k to compensate a little for the taper.
Also thinking I should get away easily with at least 3* more esp up top
Fix your boost sag so your dyno graph will not lose boner.
You shouldn't be adding timing to compensate for boost sag. If anything, your timing map should already be set up in that pressure row so as your boost level losers out and when you drop rows, you should be hitting good timing.
Also, yes, I agree that you can add slope up timing after 5200RPM.
I cannot get rid of it altogether:
I've swapped in a 15psi wga (helped a bit but still didn't get rid of it), I've relocated my boost source to the cold side for no boost reference sag, I have an mbc hooked up.
There's pretty much nothing else to do that I know of that will fix it.
And I don't really mind it much. The car pulls hard on the top end and I never even notice it.
With the subaru's I've tuned its very common and popular to ramp up timing after 6k since both the wrx and sti turbo's start to drop off big time. I don't see why it wouldn't work in this situation just as well. Its not ideal, but it should keep me from losing power towards redline (not that I feel any sort of power loss, but obviously butt dyno isn't the most accurate at measuring that).
I don't want to throw a ton of money and reinvent ****. I love my setup and the way the car is right now and have no desire to re-do ****. Just want to get it dialed in and get a dyno sheet so I know where I'm at and I'm done.
Regarding the timing map:
I'm hitting 17* at peak boost.
-Savington does the same at about 19psi? on a VERY conservative 350whp
-Leatherface hits 18* at 21psi on stock block.
-DJP hits 19-20* at 19psi.
-Miatamike hits 22-24* at 18psi
-hustler is at ~23* though at lower boost
Except sav all these guys are on pump gas.
Which makes my map look whimpy, esp since I'm on e85.
Ok so I worked on the map today just cleaning it up a little bit and smoothing it out. Not on the car cause its pouring outside, so hopefully all the changes I made don't mess **** up when I actually put it in and drive it. Added just a touch of timing up top and ramped it a tad bit where boost starts to drop off a bit.
If its not raining tomorrow I'll see how this newest revision works, and maybe kick on autotune with a small authority to perfect anything I might have missed.
Here is most recent fuel/spark map.
Anyone care to comment or criticize?
Also a couple days ago I switched the spring on the forge bov from the softest spring (~5psi) to the 5-15psi rated one. While I never had issues with the softest spring, reading a bunch of threads on other forums made me paranoid about running such a soft spring due to possibility of leaking, so I swapped it. It got a little bit ritcher at idle and low rpm/cruise, so I guess that's good lol. Also before it would "whoosh" at the tiniest decrease of throttle and its a little bit less so. No surging whatsoever though so I know its not too stiff.
Have yet to do a full boost pull on the new spring, so if I overboost when I do I'll know it was leaking. Hopefully not though.
There is a local guy with a 95 miata stock motor and same turbo as me on pump gas and w/i that just went to the dyno a couple weeks ago and with a VERY conservative spark map (according to him it was something super low like 10* at peak boost) and 14psi he made 286whp/250wtq. This gives me big hope for my trip there soon