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i was talking to ryan (vizualxtc) about this and thinking and after deciding to sell my T3 for a T25 'power on demand' type turbo, i thought why not bolt the turbo to the end of the header or cut off the header and weld in a flange and mount the turbo? technically, doesn't our stock header give out good flow, maybe even better flow than a custom or log manifold? the only problem i see would have to be making sure the turbo is mounted ABOVE the oil pan and not too low in case of floods or anything.<p>advantages: better flow, no need for expensive custom manifold/flow bench testing, save yourself some money, good alternative to b6e sohc owners if they dont want to buy a jgstools manifold<p>disadvantages: problem of turbo hitting floor if you bottom out *if its mounted too low*, should be mounted above oil pan, risky since it hasnt been tried

I think you need to look at the stock manifolds and think about that again. I don't know how you're going to weld a flange to that cast iron beast. Also, my K8 manifolds cracked from heat from the stock engine. How do you think it would handle boost?

Also, a T25 is a worthless turbo on anything larger than 1500cc. Ryan is, yet again, wrong in the suggestion to use a T25 instead of a T3 on a B6 turbo setup.

actually i thought of the T25 myself because of its fast spoolups.<p>thanks for that heads up on the header. never thought about the material factor.

The advantage of faster spool up would be in milliseconds and worthless. The over all gain of lower full boost temperatures of the t-3 would MUCH out weigh the "quick spool" of the t-25. The t-25 will just create more heat at the same boost level as the t-3, and heat is our ENEMY!!! Sure you might get a little more lag with the t-3, but the outcome of a t-3 is much greater, more reliable, and well BETTER My opinion at least...

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr>Originally posted by Timmyd865:
The t-25 will just create more heat at the same boost level as the t-3, and heat is our ENEMY<p>
My opinion at least...<hr></blockquote><p>some of that's not opinion...but fact. this is where the infamous book comes into play. it fully describes compressor effeciency.

ok then instead of the t25, what about the t28? if im not mistaken, its a hybrid of a T25 exhaust and a T3 compressor housing... now in theory, wouldn't this give me similar T25 spoolup times because of the T25 exhaust housing, but still give me more power than the T25 since the more powerful T3 compressor was mated/hybrid to it? or are there more factors that affect spoolup times. *since i have the T3 already, maybe i can get more bang for the buck if i buy a cheap T25*<p>i think they came off of sr20det motors or a few silvias... and remember im not going all out im just looking to 'bolt-on' an extra 30whp or so. then maybe later i'll start going crazy.<p>[ March 29, 2003: Message edited by: marshmallow15 ]</p>

the boost with a t3 turbo on a sohc comes in about 2800-3400 depending on setup. i dont think it will be much better with a t25 or t28. the t3 was a very nice power add on for this motor and suits it well.

ahh icic.. but everyone is assuming i want lots of horsepower, but my goal is for maybe 30-50 hp or maybe more with a bigger boost level, but i dont want the horsepower through the whole power band... only maybe from like 2000-3000 or 3500 rpms.. that's the thing. because im planning to turbo my ATX (don't hate, just wait) and since the protege lx tranny is around the low to mid 100 horsepower range with a stock pro lx, it'll be perfect for a boosted sohc.. see what i mean? maybe now you guys will know why i want quick spoolup and full boost before 3500 rpms.

so that i can get full boost before that atx shifts..<p>btw boostedmx, what injectors are you going to use for your sohc project? i already have my T3 not sure yet, im thinking of a starion intercooler or maybe a spearco FMIC for like 300 or 400, and i have my rx-7 fuel pump and rx-7 maf on the way... i know there's still more parts and little pieces i'll need to make it work, but at least the collecting of parts have begun. im just stumped as to if the stock injectors can work well or if i'll need to swap them out?<p>NOTE: im planning to go 5psi for a 800 mile break-in, then 6-8 daily for now.

actually a thought has come to mind.. since my car is ATX. ok this is FOR EXAMPLE, if i used a T3, and it spooled at around 2500 (which is when my car shifts on daily driving), would that mean if i daily drive, i would get around town normally (with turbo lag of course im guessing) and then just get power when i need it? (becuase if i floor the pedal, my tranny will shift at 4500rpms or redline if all the way down)<p>and thus meaning i would have to worry a little less about my transmission and axles?

<blockquote><font size="1" face="Verdana, Arial">quote:</font><hr> btw boostedmx, what injectors are you going to use for your sohc project? i already have my T3 not sure yet, im thinking of a starion intercooler or maybe a spearco FMIC for like 300 or 400, and i have my rx-7 fuel pump and rx-7 maf on the way... i know there's still more parts and little pieces i'll need to make it work, but at least the collecting of parts have begun. im just stumped as to if the stock injectors can work well or if i'll need to swap them out? <hr></blockquote><p>
my car is a dohc, i did this sohc turbo project for a guy down in pennsilvania. check it out here<p>http://colonelsmazdamx3.freeservers.com<p>he is just about ready for 200 wheel horsepower. minor piggybacks and some more tuning will need to be done. i suggested a small shot of nitrous but i dunno if hes taking that seriously just yet. as for the injectors he is using 300cc injectors that i had left over from a past turbo project. if you are only wanting 30hp more dont bother.<p>another thing,why would u waste power in an auto tranny. they are torque eating slushboxes. the auto to 5 speed conversion i did to chris's car
made the car fun to drive and made use of the new power. its cool to be different but thats just the wrong way to go

if your trans shifts before the turbo spools then you won't have the lag. (i think that's what you were asking above )<p>you would get the power when you stepped hard on the gas, in turn making the engine rev higher before it shifted.<p>i would go with this setup if i was you, because the only time i want to go fast is when i stomp on it. and you get better gas milage when you are below the turbo spooling RPM. (it would however be better with a manual like said above)

yea i know i know manual transmissions.. but i already have a manual rx-7. for the mx-3, im just looking for more power but i don't want to hassle with shifting gears all the time *i do lots of stop and go driving*... im an automatic kinda person.<p>plus i contacted levelten about them upgrading a pro lx tranny when i get one, they said once i start putting the pieces together and their upgrade kit for the transmission causes the tranny to start slipping *im not going to abuse the power much*, then they will replace the transmission and back it up with a 2-year warranty.