DISI-MZResponse 2.0

OK well I couldn't think of anything clever, so here we are.

For those that aren't in the know, original thread with explanations of original build and entire history up until today is here:

https://mazdaspeeds.org/index.php?threads/disi-mzresponse.457/


PLANNING AND DISCUSSION PHASE

Engine
What isn't changing and why

• Same 2.0 (1.996) Liters of displacement
  Lower stroke makes it easier to rev and increases VE

• Same headwork (bowl work, gasket match the hot side, stock combustion chambers)
  No need to go crazy with headwork on a 95% daily driven car with modest power goals

• Stock valve sizes
  VE increases with the destroke already, and larger valves tend to flow worse near shrouding points

• Stock bearing clearances
  Torque goals are modest; 300-350 max WTQ so should be fine and will let me run the same, proven corn resistant oil I have always run

What is changing and why

• Closer to normal pistons (smilies with higher compression)
  Should improve efficiency and drive-ability off-boost

• Shorter rod ratio; from 1.92:1 (current) down to 1.8:1
  Will help with cylinder filling and reduce piston slap at lower RPMs (currently idle is set to 1100) while not sacrificing high RPM breathing

• Kelford cams, possibly custom grind with higher dynamic compression ratio
  Higher dynamic compression should make the engine more efficient off throttle and make better use of full corn on throttle. Also I'm pretty sure Crower fucked me on my cams (not to spec), and I wouldn't trust them anymore after the whole debacle with VashExe anyways

Turbo / Exhaust
What is changing and why

• Manifold
  I like options and clearance; maybe a screamer pipe would be good.

• Different turbo
  Just want something that's easier to work with and matches my engine goals; no more shitty custom intakes, impossible to get right coolant lines (still worried my current one is going to fail and dump coolant everywhere) and leaky oil return (oil is actually bleeding through the hose)

• Turboback
  Something bigger than 2.85" and closer to 3.25 or 3.5" would be good for flow at high RPMs

Other / Misc
What needs changing (advice very welcome)

• PCV
  This right here could very well be my number one problem, so whatever new setup I run, I'll need to have it set up for large amounts of flow; ideally, maintenance would be low (catch cans that drain back to the pan, maybe? Oil coming out of the engine looks great as it is and previously tested well). I'm not a big fan of catch cans because there's not a lot of working room for me to get to them for draining regularly (unless it can be done by only popping the hood). Draining with oil changes would work though.

• Shifter
  So yeah, the TWM was an utter waste of money, and in a bad way. I still have my stock shift assembly, so any kind of good aftermarket short shifter would be good, and I'll see about using the Tallboys to keep it raised up a bit higher if needed. I do still like the AP shift hammer, so very likely keeping that.

• Spare tire well
  Currently, this is empty and the factory cover for that is sagging like a motherfucker. A WMI tank would kill two birds with one stone, but I'm worried about damage to fuel/power lines so close to the exhaust here, and do not want to run anything through the cabin for obvious reasons.

Potential changes
What might be changing (advice very welcome)

• Intake manifold
  I still have the ST mani collecting dust; maybe this is a good time to go full PI, as I already have the ITFP for it and this will solve my current fueling issues, but I currently only have the WMI one.

• Intercooler
  The TMIC is proving to be a pain in my lazy ass when it comes to checking shit; might be time to go chemical only or FMIC, since the CS TMIC I'm using right now probably won't be up to the task of cooling ~500 ish WHP of charge air anyways. I could modify my CPE like Vash did, but that prevents the use of the ST manifold and it probably wouldn't like the heat generated from racing.

• WMI
  I still want to run 50/50 (or another mix) WMI for additional cooling, but wondering how far I'd have to go to get enough cooling to be viable with chem only on full corn. Unless there's some kind of ultra reliable controller for these that's small and easy to set up, I'll probably stick with a boost switch on this like I used to have.

• Charge piping
  Is under-route still a viable thing with larger size charge pipes? Having these out of the way sounds like bliss for checking plugs and such, but isn't that much of a concern if I can get the FoST mani routing good enough.

• Clutch
  I'm currently running a Fidanza aluminum FW with Luk pressure plate and stock disk. It's easy to drive but the engagement/disengagement points are kind of numb and the pedal is a bit soft.

I can't think of a lot else at the moment, so I guess I'll stop here. Discussion, suggestions, questions, etc all welcome.

 

Forgot to mention, that this will all be 6+ months out for the big stuff. I have a bunch of computer shit I have to buy/build before I can start funneling money back into the speed.

 

Are you going to reuse the head from the old motor?

 

No, I won't have the time needed to build up the second motor myself, so I'll have someone who actually knows what they are doing do it. I'll probably tear down the current motor myself to see what the fuck though.

 

I will throw in my 2 cents about the underroute piping because I like and admire you.

I had the HTP piping kit, with tr10C and treadstone crash bar. The piping kit itself was great quality. However the underroute kit is a pain. Tightening the tbolt clamps on the turbo is a BITCH because of the downpipe and hot pipe now both getting in your way. Much less servicing your turbo oil or coolant lines.

Boost leak testing is difficult because of all the couplers, eventhough with the HTP kit I only had 3 hot and 3 cold couplers. You will always need to put it on ramps and take off the belly pan, maybe even the bumper. I think I could only get 1k miles without developing a boost leak, and that was with support brackets on both the hot and cold pipe.

You will need to fab a small bracket to keep the hot pipe secure, and the 2.5" puping is VERY tight on a couple of corners. So I suggest you think twice about using bigger piping.

I had the intercooler right on the bumper, but I was having serious lift issues due to all the cutting and removing of OEM stuff to make everything fit.

Let me be clear, I am not dismissing your intent or trying to shoot it down. The underroute kit is just not as convenient as its made out to be. Yes you can check your plugs and fiddle with other things easier, but it is a lot more time consuming than a TMIC if it ever needs to be serviced.

 

Charge piping: Look at how CS runs their kits now. Everything is over in the intake area and not under-route or flopping on the engine.

WMI: Stick with a boost switch. CoolingMists controller, while a nice idea never worked correctly because it never would fill the tables in learn mode. You'd need a dyno to efficiently and correctly fill the voltage tables manually. Aquamists controller probably works great, but $$$ and wiring.

Shifter: Fuck a short shifter, just get a setup like this: https://mazdaspeeds.org/index.php?threads/custom-shift-cable.2937/#post-27574

 

D'aww, shucks.

Let ME be clear: This thread exists explicitly to garner feedback like what you've posted. Many thanks.

Noted on all counts, but I would still like a short shifter with an extension as I like my hand to be closer to the wheel.

 

I have never bothered with under route for the very reason of having to service/troubleshoot it. I have the turbo xs fmic kit and it has worked great. I would go PI with the ST and fmic. You can do a pretty short run to it with the TB facing down.

If you don't have injectors yet def look at the siemens deka "check my build" they are cheap and work perfect.

At your power level you could run a return less system without issue. IF you wanted to get wild you could run a fuel cell where the spare tire is and make that PI e85 while running e50 mix in oem tank. I would honestly just do a simple returnless PI setup to get you on the road and tweak later.

I would make it a goal for you to make some power and get the car reliable before you go balls deep into side projects. Once the car is running well and it is in a good place you can start to tweak stuff. I got my car up and running and tuned on just 93 while I did break in and about 6 months later I added PI. Same goes with meth, make whatever power 93 will give you and get a couple thousand miles on it and then start the mad scientist stuff.

 

Yes this, it takes like 2 min to take the tmic pipe off and on to access plugs.

 

I use a damond short shirt plate and a stratified shift extender with a stock knob and it works pretty well. Oh and shifter bushings but I assume pretty much everyone has those by now

 

I talked to you on the discord a long time ago regarding shimming the stock shifter basket with either a stock shifter assembly or the CS one.
Still felt better than a TWM assembly
I'm yet to find a better solution than greased duct tape to use as a softer shim
My current setup and would recommend to anyone: CS shift assembly, shimmed shifter cup. No SSP, no shift weight.

 

I have my stock shifter assembly laying around, so maybe I'll give that a try; to clarify, you just line the shifter ball with duck tape and grease it with, what white lithium?

 

Yeah line the cup with a few small strips to start, and add to get the desired "stiffness" that you want.
I used lithium marine grease as that's usually my go to, but white lithium should work.

 

Oh yea I white lithiumed the hell out of the ball and the end of the cable made a huge difference

 

I haven't touched shifter cables yet but for a stock shifter cable setup the shimmed cup definitely helps with shifter slop

 

So, currently leaning towards a 5558 since Edge has a kit for it. If a downpipe would have had to be fabricated, then I'd likely run a G25-660, but currently lazier is better.

As a side note, I'll probably wind up buying shit before I even get to the engine portion and install it on the engine I already have, so I can eventually do a comparison between engines....You know, for science.

 

Well you should make sure to get the full zoom zoom boom experience from the current motor

 

I'm working on it; beat the fucking shit out of it today and probably lost half a quart as it is.

 

The Cams

Crower can fucking suck it.

PCV

This is probably the way you should go for PCV, I think a lot of your problems stem from this after seeing the set up back when we got that motor in haha.




I'm set up the same way and do not have to drain my catch cans any more frequently than during each oil change, so I wouldn't say it's a problem at all. Routing to the oil pan sounds like a huge pain in the ass.

Spare tire well

I've just started running a full size spare. A 245/40 -18 fits perfect in the genpu slot and I was able to just put the existing cover over it without too much tweaking. I obviously don't have the stock sub in there anymore.

Intercooler

TMIC is cool and I think I've proven that you can make good power with one, but man is it a huge pain in the ass to live with. Every time I have to do plugs or anything else I have to unhook a fuel line and it sucks ass. A nice FMIC setup would probably be preferable.

Clutch

I ran the Luk+Fidanza combo and if you make even a couple wtq over 400 you will smoke it. Mine immediately died after getting above 390wtq and I can't imagine that it'll last too long anywhere near that number. I picked up an ACT 6 Puck Clutch Kit + Streetlite Flywheel (ZX5-HDG6) to replace it and honestly I noticed no real difference in pedal feel or anything like that. I really didn't want a stupid leg day clutch that was shitty for DD and I honestly can't recommend this one enough. Holds the power just fine and is great for DD duty.

 

Yeah I've been reading up on that and that's probably what I'll move to next; probably have to fab up a bracket or something to lift it up higher so I can drain it from the top of the engine bay without having to jack up the car.

I actually want to put something useful in there; a while back I drove 2 hours at highway speeds on two flat front tires and didn't realize it till I did a pull and found it to be a bit wobbly. TPMS had died, so didn't know.

I'm eyeballing the CS intake mani, which, with short injectors, should just barely clear a TMIC as far as fuel rail goes. I could always have a custom TMIC made as well, later on.

I'm not sure I want to go all in on another full setup, but that depends on how long that 6 puck will last you and how hard it bites.