lazzer408

iTrader: (1)

I can reach the plug on mine. Maybe my arms are long. I do the filter from above. It's a 15min job. Ofcorse... if the last filter was cranked on to tight and 2 filter wrenches, a flat blade thru the filter, and a pipe wrench doesn't get it loose then it's a 2 hour job since the manifold bracket has to come off to get at it cause the sending unit is in the way due to turbo cooling lines... -sigh- That was a bad day.

mazda/nissan

iTrader: (2)

The filter is a bitch to get to with big hands, took me the better part of an hour to contort my arms under the intake manifold. In other news: I agree that lower compression makes room for more boost, but while out of boost you better be running nitrous to make up for the power you took away because you can't always be in full boost. Take a look at yadayada's turbo setup, he's running 10:1's and making 230hp at 8psi; true he can't boost as high as 9 or 8:1's can but he still has power out of boost and doesn't have to run as much boost to get the same power as 9:1's do. But as someone has already stated, this is my *** speaking.

guitarrc6

haha good point, i totally didn't think of pre-boost. when i get on this site i kinda get tunnel vision.

has anyone run the T3/T4 with 50 trim setup? how did that work out for them. i'm debating on if i should just keep the HP lower, (t25 turbo) or go all out (T3/T4) i'd want the more power and could put up with the lag, but is it worth the time and effort to build up the motor for the t3/t4?

AND is it possible to run low boost with the t3/t4 and still enjoy the car (basically trying to save the stockie parts until i buy the new ones) ?

i need to go do something productive.....

guitarrc6

haha had to get the 20th post to be "miataturbo" LEGAL!!

eunos1800

What a great thread.

Surely the whole purpose of lowering compression is to reduce the det threshold?

If you Fi a Miata at 20 psi your gonna have to retard the timing by a fair margin unless you have WI or use high octane fuel.

The result of retarding timing is astronomical EGT's, even retarding my stock timing by 6 degrees from a 14btdc base gives me over 900c EGT's at only 9psi.

Now double your boost and retard your timing even more and your starting to get in engine component melting temps.

Lower the compression though, and hey presto all of a sudden you can start clawing timing advance back in turn steadily watching your EGT's drop.

Until you up the boost again of course


Also remember that your MBT will change dramatically depending on your compression and boost.

From what i've seen so far, reaching MBT before det starts occurring is the real balancing act, with boost playing the lead role.

I've never worked on a Miata running over 20psi of boost, but i imagine on the stock compression ratio its virtually impossible to reach MBT before knock starts raising its ugly head.

Anyone running 20psi + on stock compression ratios?
Can you get anywhere near MBT without WI?


Cheers
Mark

guitarrc6

EUNOS thanks for the info but it puts up a question i asked in another thread. if you are screwing around with the timing that much, can you set up your turbo to only hit 4 psi and then put it on a switch for 15? evryone was saying that you can with an MBC or multiple MBCs blah blah blah but its not the actual ammount of boost, how would timing be affected for the switch? or would you just tun timing to the high boost level and suffer with a subtuned engine at 4psi?

yeah this thread is good cause its like theortical so every can pitch in.

mazda/nissan

iTrader: (2)

well it depends on what ignition retard systems you have on the car. Some systems will automatically retard timing if knock starts to occur, so if you have a system like this you can switch back and forth all day and the system will read this change and therefore change your timing...... i think

eunos1800

What he said,

I'm probably not the best bloke to ask as i'm running a SC.

But don't the PRofec E-01 and EMB or EMU work together?
If the EMU could control the boost, then you could switch between timing maps on the front panel.

You'd also need 2 injection maps to switch between as well though, the fuelling needs at 7000rpm at 4psi are a damn sight different to the fuelling needs at 7000rpm at 15psi.


Cheers
Mark

Paramour208

Eliminator77 from the miata.net forum recently posted a 493hp dyno using the 50 trim hybrid. Keep in mind he has done a lot to get to that point and is looking for maximum power.
If you are wanting something that spools fast, his setup might not work for you.
You need to determine your hp goals, then match your turbo to that goal. In general, the more power you want, the more lag you will have to put up with.

As for the stock internals, I have heard of several people running 8-10 psi on otherwise stock engines. If I were you, I would upgrade the injectors so that you minimize the chance of a lean down condition due to fuel starvation under boost.

guitarrc6

cool yeah thats like 150 more hp than i was thinkin i wanted to be between 300 and 350 with forged internals. i was thinkin the gt28rs but from what i read that maxes out at 320 and with my lead foot i wouldn't want to overstress the turbo. so i'm looking for the next best alternative, thats why i was thinkin the T3/T4. i would upgrade the injectors and stuff, basically i want to make a kit thats detuned for the stock engine while i save up money for the forged goodies that way i can run boost while i'm waiting, and by the time i get sick of only 160 hp i'll be able to swap in a different motor and get twice that!

Paramour208

Get a t3/t4 50 trim with a .43 ar hot side. The small hotside will spool relatively quick at the cost of top end power. Later you can upgrade to a .63 or .82 ar hotside housing for minimal cost, you just unbolt your hotside housing from the chra, bolt the new one one and go. That would probably be your most cost effective solution, and only require buying one turbo.

The advantage: You could use all the same connections, and just change springs in your wastegate and bov when you want to add boost, or use a manual boost control valve.

magnamx-5

iTrader: (7)

dude 160 hp are you getting a M45 :gay: go with a 3271 and the 300-350 is doable. with less lag. And remember people it isnt the boost it is the air flow that kills us.

guitarrc6

airflow or boost i just wanna make sure i'll have a turbo that can support the level of power i want it to.

Paramour208

Boost is POWER! You increase boost, up to a point of diminishing returns, you create more power!

Airflow is efficiency, The more airflow your engine is capable of, the more power it can make on a given AMOUNT of boost.

A stock engine will produce significantly less power on 8 psi, than a built engine with lower reciprocating mass, larger valves, extensive flow work on the head, etc.
He wants a turbo that is CAPABLE of giving him the power levels he wants, AND still have some room to grow. I still stand by my former suggestion. The 50 trim t3/t4 WILL be a bit more sluggish on his stock engine, but as he adds to his engine, INCREASES the airflow capability of his engine, the turbo will spool faster and make more power in the long run.

guitarrc6

cool thanks, yeah i'd probably do a mild port and polish myself, and at least get larger valves. upgrading the cams would be like last on my list of stuff to do. what about the turbo on this site? (the one that retails for 489) http://www.westcoast-turbo.com/turboa.html

DamienSTi

Crower will cut you a one-off crank starting at $2400 or a full 4 cyl one off stroker kit for $4000 or 6 Cyl kit for $5500.

http://www.crower.com/cat/stroker.shtml

Paramour208

If they are reputable, that is a hard price to beat! I got mine at cost and still paid more than $500 for it.

Pitlab77

iTrader: (3)

racing mazda uses stoid

Markp

Yes, with a .48 hot side you can have a very enjoyable T3/T4 at low boost. Even with the .63 hot side at low boost you can have a lot of fun. Is it worth it, oh hell ya, the delay in boost is worth every bit of HP. 300 RWHP is very enlightening and considering that this was happening at 17 PSI of boost, there was a lot left in that T3/T4. It felt VERY solid at 10 PSI of boost although it was late to spool (1st gear spool was 5000 RPM, 3rd gear 4500 RPM, 4th and above was around 4200 RPM spool.)

Mark

Paramour208

Guitar,
I found something you might want to read bfore buying from WestCoast!

http://www.turbod16.com/viewtopic.ph...c772e7021d8ef8