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Rear mount 12v, Simple questions before getting started.

1K views 15 replies 4 participants last post by  Audi90sportQ 
#1 ·
So i just began college and plan on starting my project to rear mount my 95' 90. I have all the basic mods, IE: Large bore MAF, TB and gasket matched IM. I plan on running 5psi just for a little bit until i get the kit dialed in, and then add meth inj. and most likely standalone. I plan on getting a custom burned chip for a 5psi tune from 034, i think that is reasonable until i can scavenge the money for standalone. Im going to have to stay stock compression 10.3:1 until i can afford pistons, so how high could i up the boost with meth inj before detonation? and what should i gap my plugs too? Let me know what i should watch out for when piecing together this kit. I wont be running an intercooler until i go above 8 or 9psi.
Thanks
Dustin.
 
#4 ·
if your handy do some variable resistor hacks or the like, if your not so good, get an interceptor like an apexi afc or the like... get one used and cheap.

you WILL need some way of trimming it out, especially timing. which is why im suggesting these.

with all these crutches and methanol injection, it would probably be ok.
 
#5 ·
I was thinking about throwing in an AFC so i could trim the fuel, Im going to have to do more research because i dont know if you would want advanced or retarded ignition in low boost situations, and all my crutches. I will have to contact 034.
 
#6 ·
you have an engine with 10:1 compression... all you are ever going to do is retard the ignition! LOL
 
#7 ·
I wonder how well 034 would be able to burn a chip for a car that is not on their dynos. I have a couple of IHI turbos from a 2.0l Jap spec Legacy that made 280 hp from the factory. They are tiny little guys, and I have often played with the idea of cutting off the flanges and welding on V-bands like i did on my 30r. They are light, and I bet you could just put them at the bottom of the stock downpipes and run 6psi all day long with the internal gates. It wouldnt be a rocket, but I bet 250 whp would be possible with the right tune.

Hrm.. that would be fun..
 
#8 ·
the_natrix said:
you have an engine with 10:1 compression... all you are ever going to do is retard the ignition! LOL
Haha true true, i contacted Eagle for a custom set of pistons, and i didn't know what compression i wanted im thinking 8.8 or somewhere around there? Can our rods take 300hp? I got my oil pick up pump and return most likely going in the trunk, and im just going to have a shop weld a bung to my pan.
 
#9 ·
my v6 i had made them for 8.8:1 but i also dropped the combustion chambers a bit with cleaning them up and such by 3-4 cc ... so in the end it will be mid 8:1 compression. which is fine considering the watercooling on the v6's heads is about a bajillion times better then the 10v.

i had arias pistons make mine, so they have the cad design already. when i get home and i find the work order, you might beable to just give them to the arias guys and get the pistons done. i think it was around 600-700 ish but they are completely custom forged pistons with several key design changes for turbo duty, i kept the conrod piston pin offset so the pistons would run quiet like stock.
BTW the arias guys were VERY impressed with the factory ring set, and wanted to know everything they could about it ( i did send a set but they wanted to know more) so imho if you get custom pistons made by someone else, make them use the stock rings. PS be careful and dont fuck up the conrod piston pin bearings..... otherwise your either looking for a new conrod, or an entire conrod set ;)

the rods are the same as the v8 rods which guys are abusing left right and center, so all in all considering this has 1 more piston then the 20vn/a motors id assume 300-350 could be ok with GOOD TUNING.

what oil scavange pump are you going to use? not one of those assball diaphragm pumps is it? im going to use a good gearpump (because i dont want my car to sound like an sears aircompressor) and the like with an improved water/oil main oil cooler and a secondary oil/air oil cooler on the turbo feed line.

why bother WELDING a bung in the oil pan? its cast aluminum, drill and tap for 1/2 npt and thread one in there instead of paying some monkey to do work. what pan are you going to modify? the upper or lower pan? be very careful on the upper pan it has the oil pressure control system in it.
 
#10 ·
Ya ya you should really get those receipts because i was quoted closer to 900 bucks! this is getting me excited, if i could get those pistons then maybe i could just have they guys at 034 set me up for 12psi, bassicly the chip will just be for timing purposes and maybe a baseline A/F graph since i plan on dialing the fuel trim in with an adj. fpr or an afc. Anyways im using a pump from scavangepump.com and plan on returning the oil through the oil cap? And that is a very good idea to tap the pan, i plan on doing the lower just for ease of access if a leak or line replacement were to occur. Now im trying to figure out how to regulate boost. I was thinking about getting a turbo with an internal waste gate and cranking that then using my already owned mbc to set the boost to what my tune is. How far are you on your build up? and pictures and or tips? are you going rear mount or where you the one who tried running the exhaust pipe under the pan for a passenger side mounted turbo in the bay?
 
#11 ·
wait wait wait.... if your drilling and tapping the pan, why would you return the oil through the oil cap? seriously wtf?, the reason you put a fitting on the pan is to return the oil there. unless you were thinking of getting the oil from the pan to FEED the turbo? cause that will not work, you need to get oil from a pressureized source, the easiest would be to put a tee fitting where the oil pressure sensor is.

asfar as my own setup... thats to be announced when its finally running :p
but yes im the guy that your rmt a4 guy was talking to about the crosspipe running under and infront of the oilpan.
 
#12 ·
the_natrix said:
, you need to get oil from a pressureized source, the easiest would be to put a tee fitting where the oil pressure sensor is.
Ok Ok good thats what i was thinking, but I was just thinking the pump could pull oil from the pan, So pushing the oil back into the pain through the tap is a good idea? I was searching and im going to stick to the K03 turbo with and internal waste gate at 8.7psi, which im going to limit to about 5 or 6 ( which ever i get the tune at) with my mbc. What do you recommend for plug gap when running around that psi of boost?
 
#13 ·
you want the engine to supply the oil pressure. the oil pump is strictly for the return line after the turbo! this is because as the oil passes through the turbo, its turned into a whipped foam and will not flow like oil anymore, it flows much more like whipping cream or something like that.

this is why the feed line is 1/8 npt, but the drain line is a giant 1/2inch hose drain.

because your planning RMT you require a scavange pump with very high volume to pump all this oil back into the engine... anywhere is ok, but if you can install a check valve in the returnline (AFTER THE PUMP FOR GODS SAKES!) or keep the entire system above the sump level, then you can pump it directly back into the pan. otherwise its recommended to pump that oil above the sump, through either the upper pan, or side of the block somewhere.

so this is how it works to be 1 billion percent crystal clear. oil pressure sensor > tee fitting> tee fitting feeds oil to turbocharger oil input> turbocharger> turbocharger drain line> oil scavange pump> return to unpressurize hole in engine (oil cap, side of the block where its safe to return oil, oil pan (upper or lower))

honestly the ignition system on the 12v cars is pretty decent, stick with the factory gap and run plugs 1 number colder.

the k03 sounds like a nice idea, but if it were me, id do it different... slightly bigger atleast. my impression of the k03 is its overworked in the 1.8t's that are making 150 hp, putting it on an engine that already produces 180hp isnt performance.
look for a minimum of the larger t3's like a super 60 or something. your pulling a ricer trick, which is taking a high compression engine and boosting it... basically you want airflow to make more power, and you want it done efficiently with minimal intake heating. a tiny turbo is not the way to do that. most ricer setups for high compression low boost, use a big t4 turbo, then you just gotta select the right turbine to spool the turbo properly without putting you into surge... there are other tricks too. but you get the idea.

dont go too small.
 
#14 ·
Perfectly clear now, I think i will return through oil cap. And you are actually right about the high compression big turbo idea, since my engine will be pumping out more air than a lower compression motor that little snail would be able to keep up, the bigger house like a super 60 would also provide a more suitable back pressure in the exhaust track i would assume. Im going to start looking at some Pressure maps. Problem is i would have to buy a waste gate now, hmm i shall research.
thanks for the input keep me updated! [edit]: After doing some research i did find a T3 with a internal wastegate! with and AR of .53 which is alot better than the ko3 .36 or something like that. One quick question about oil return. Should i place the return pump lower than the turbo using gravity or do you think the pump could pull it up and then push it back? I guess it really depends on what kind of pump i get.
 
#15 ·
you dont have to buy a wastegate... most t3 and t3/t4 turbos have integral wastegates.

dude be very clear on what you are reading on the turbos, as most people get confused and dont understand whats going on. the compressor map (not pressure map) will indicate efficiency vs flow vs pressure... you want a turbo that will flow your expected HP of air. hence my suggestion of avoiding the k03.

the A/R for the compressor side is not of particular importance... please ignore it, if a turbo states the A/R but is not CLEAR about which side, then ask for clarification... you only use the TURBINE SIDE A/R as an indicator of how restrictive the turbine can be, and thus how fast it may spool.

most ebay turbos completely ass this up and state the compressor side A/R, and do not state the compressor wheel trim, or call the compressor wheel trim the A/R in which case this becomes very confusing.

read these
http://www.automotivearticles.com/Turbo_Selection.shtml
http://www.moddedmustangs.com/forums/po ... -trim.html

infact read everything on turbos until you clearly understand it, and go to the turbonetics websites and get a feel for how the garrett turbos are sized... once you know what parts are normally made for the turbos, you will spot missmatches and screwups on things for sale... ie 0.53 is not a common A/R for the exhaust turbine. 0.63 and 0.48 are, so something is jacked with that turbo or he is quoting the compressor side A/R which is kinda meaningless.

http://64.225.76.178/main.htm

http://www.turbobygarrett.com/turbobyga ... onyms.html

lastly, it is best to allow the pump to be lower then the turbo for maximum effectiveness... since its pumping a slurry of oil/foam that stuff does not travel easily up hill, allow it to gravity drain to the pump, and then let the pump do the work pushing. pumps are awesome at pushing but litterally suck at sucking unless its in an incompressible medium (fluid), and even then its not perfect.
 
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