I'm building a Tii with stock port motor for my 88 and since its stock internals, i want to keep it conservative for reliable so im shooting for 12-14 psi. I will be running Borg Warner s363 (.88 undivided), divided tubular manifold, FMI, complete KGParts fuel system, racing beat exhaust, tial wg/bov and tuned on Microtech LT-10. My compression tests came back with over 90 psi on all faces with a dieing battery. my mechanic said with a fresh battery, he would expect well over 100.

anywhoo.... with the list above, can anyone tell me how much power i would expect from 12 psi vs 14 psi?

thanks!

 

the S363 is a 570 rotary hp turbo and as such it really is not the right size for your objectives.

check out my sticky thread "Turbo Comparisons" and look for a turbo around 6.3 sq inches or less. (60-1)... that way you won't be pushing too much wheel mass and your wastegate will have an opportunity to close

it may not be possible, even w a wide open wastegate, for you to put your foot down w a S363and be in your desired boost range.

if you already own the S363, you will need 850/1600s for fuel and i suggest you spend around 300 for a base water injection system as you will not be able to hold that setup under one bar and the water will keep your motor internals both clean and unbroken.

it is very difficult to predict hp at low boost levels as alot of complex things come into play. i will leave it to others.

good luck,

howard

 

Its definitely not easy to predict a power level unless you have a fresh motor, and specific other factors being known.

If you have a divided manifold, why not use a .91 or 1.00 divided turbine housing?

 

thanks guys. i asked about those specific items because i already collected them. my s5 motor is a brand new crate motor that was never installed in a vehicle. it is not a reman/rebuilt and was sitting at a mazda dealership till it closed. so its essentially as new/fresh of a motor you can get.

a local has a used R85 kit that uses a modified s362 for 1,800 so i thought it would be smarter to buy a brand new s363 since i found it for 725 shipped. unfortunately they were out of stock on the divided housings so i purchased the .88 undivided and was told that should suffice considering i was buying a divided manifold and the ar is small enough to help with low end boost.

then i went on to purchase other supporting mods and ended up with the Tial 44mm wastegate and 50mm Q BOV. For fuelling i bought a surpra pump and KGParts fuel system that came with primary and secondary rails, injectors, lines, automotive fpr AN fittings ect.

...so thats how i came up with the parts. its my first time turboing a car so im not familiar with the logistics of what parts work better with what and on how much boost. Howard, when you say "that way you won't be pushing too much wheel mass and your wastegate will have an opportunity to close" im assuming you mean the turbine wheel? why would that happen in my setup and why might that be bad? sorry for all the noob questions but what will cause the wastegate to stay open and, again, why is that bad? lol

I dont really have the option of returning these items any more since they were all mostly ordered. Im pretty much stuck with these parts. with that said, should i just run higher boost levels with my setup? in essence, are you saying i may damage or ruin something down the road by boosting under 1 bar? how would water injectors help in this case?

i have put my fire suit on so feel free to flame on guys. at least i might learn something. i have spent a lot of dough and have not really been told "im doing it wrong" lol so if there are any suggestions, please HELP =)

 

your mechanic is not a rotary mechanic? he didnt suggest a setup?

 

Care to elaborate on this statement, not questioning its validity just curious as to why this is?

Thanks!

 

So the point of asking questions about your system components after they are purchased would be what.....? If you're dead set on a certain boost range why not find a turbo that is on its efficiency island at that boost pressure? Why waste a divided manifold on a collected turbine housing? Have you done any research on turbos at all? (serious question)

 

he is and he suggested the r85 kit but because i'm on a budget i went with putting my own kit together which was a lot cheaper. instead of buying the kit or paying 1800 for a used one, i tried to imitate it.

 

^^+1 lol

 

the original point is, like the title asks, what power would i expect?.. im not "dead set" on a boost range. 12-14 psi was my goal to keep the major components (engine,turbo) relatively reliable enough to last at least 50,000 miles. i was unaware that a Borg Warner s363 or any of my other purchases are inefficient for my boost goals. i knew the kit i put together is capable of a lot more than my current goals but i still went with it because i figured that when im ready to make more power with a port job, all the components would be there without me having to buy things all over again. I thought worst comes to worst, relatively low boost on a bigger turbo would mean it would take longer to spool, reach full boost or lag... but it seems that most of you are suggesting that 12 psi may be damaging at worst and not very efficient?

i know it can be irritable when a new comer doesnt familiarize themselves as much as most forum member would hope but i tried to read what i can with the time that i have and thats why input from those of you who are experts on this trade are seriously appreciated. my bad yall

 

That turbo will work, and you can expect similar/slightly lower numbers in that boost range than more 'normally' sized turbos. say ballpark 275whp

That said, for your apparent goals, you would be much better off with an s256 or soemthing in that size range.

 

i was hoping for closer to 350whp haha

guess ill push for 14-15 lbs to reach my goal...

would a new, good condition/compression, stock port S5 motor see another 50,000 miles with 350whp assuming it receives routine maintenance?? i dont plan on beating on her at the track, launching the snot out of it or redlining every gear but obviously i would drive her pretty spiritfully here and there on the highway ect

 

16 psi