Reliable and responsive 320whp, All opinions wanted

[kilcourse64]

So I am fairly new to the SR scene, and am really looking for some opinions on the most cost effective way to obtain a reliable and responsible 320whp SR (Yes I've searched). My previous experience lies with the boxer engines of Subaru's, and Audi's 2.7L Bi-Turbo unit, so this is new ground for me.

I have searched for hours and hours over a period of many days, but I've arrived at the conclusion that first hand knowledge from SR owners themselves is the best way to go about achieving my objective.

Now this is what I know so far: First off, I do not trust these SR's that all of the engine importers are selling, it seems that regardless of where you go you can get a bad tomato. So I want new internals, but my question to you is, what do I get? Going inside an engine is beyond me, and I will be paying for someone to install these parts. But basically I am looking for a torquey and reliable 320whp, so what internal engine modifications do I need or would you suggest? What would your spec sheet look like? I don't need a bulletproof engine, just something reliable, as I just don't trust these older imported engines.

Now for turbo options, I've read that for what I'm looking for, ideally I should be going with a twin scroll GT3071R from Full Race, but I'm not sure that I want to drop that kind of money, so what are my options? 850cc injectors, a Walbro 255, and a Z32 MAF all seem to be common in this range as well, but if you can point me in a better direction please do.

Any and all info will be of great help.

[kilcourse64]

Sorry to sound so impatient guys, but I really would like to hear what everyone has to say. 320whp is a minimum, so if you get bored with that number feel free to bump it to 350whp.

[jdm240sx122]

Ls1...Done and done
A relaible 300 to 350hp all day long.:rl:

[Pure_JDM]

For 320 at the wheels, you won't need anything forged, but if it helps you sleep at night, then get some CP pistons, an Eagle crank, and a GT2871R should put you at that level to my knowledge, but as you're stating, go with the GT3071R. No reason to spend that kind of money on a Full Race if you're only wanting that kind of power... Garrett, Precision, Turbonetics are plenty reputable for quality and reliability. And as you mentioned, a Z32 MAF, a Walbro 255, and injectors 600-800cc should be plenty.

[lazysk8er2]

before you get flamed badly as you seem to be a nice guy i would recommend to search and read the stickies and then search some more.

after 20 years theres more than enough info to google your basic question.

[Pure_JDM]

http://zilvia.net/f/tech-talk/124925-gt2871-users-sr-motor.html

that should help if you're questioning the GT2871R.

[s13 loverr]

First off GT3071r is huge for 320whp those turbos are for 400whp and up. Forged Pistons are not needed for that amount as 400whp can be hit with good tuning. GT28's have great response and can hit up to 400whp if you are pushing the turbo. 850cc injectors are also big for that amount of horsepower. If you don't know how to check out an engine yourself then take it to a shop and have them check for compression, leaks, etc. Check out the chat forum has lots of people's car builds to see what they are running.

http://zilvia.net/f/chat/

Read all the stickies to help your searching and before someone gets mad theres is a small questions thread here if you still can't find anything next time you are searching.

http://zilvia.net/f/chat/297481-small-questions-thread-use-insted-making-new-threads-61.html

good luck with your car!

[kilcourse64]

Ls1...Done and done
A relaible 300 to 350hp all day long.:rl:

I've considered it, but that just kills part of an S-chassis's spirit in my opinion. Not to mention they're pretty heavy engines and can disrupt weight distribution, so it's just not an option for me.

before you get flamed badly as you seem to be a nice guy i would recommend to search and read the stickies and then search some more.

after 20 years theres more than enough info to google your basic question.

I actually did read the stickies, and have done a lot of searching, but it's hard to know what to look for when you have no experience with the engine you're searching for info on.

http://zilvia.net/f/tech-talk/124925-gt2871-users-sr-motor.html

that should help if you're questioning the GT2871R.

Yes, this is definitely useful. Thanks for the help, your earlier post was almost exactly what I was looking for.

First off GT3071r is huge for 320whp those turbos are for 400whp and up. Forged Pistons are not needed for that amount as 400whp can be hit with good tuning. GT28's have great response and can hit up to 400whp if you are pushing the turbo. 850cc injectors are also big for that amount of horsepower. If you don't know how to check out an engine yourself then take it to a shop and have them check for compression, leaks, etc. Check out the chat forum has lots of people's car builds to see what they are running.

http://zilvia.net/f/chat/

Read all the stickies to help your searching and before someone gets mad theres is a small questions thread here if you still can't find anything next time you are searching.

http://zilvia.net/f/chat/297481-small-questions-thread-use-insted-making-new-threads-61.html

good luck with your car!

I appreciate the well wishes! I've read the SR sticky and a few others, as well as searching through the forums and outside of Zilvia, so I have been searching, but it's like I said above, it's hard to know what to look for when you have no experience with the engine that you're looking for info on.

I know GT28's can lay down some high numbers, but you really have to push em, and the main reason I brought up the Full Race twin scroll GT3071R, was because I had seen a dyno chart of one spooling quicker than a GT28, and of course the GT3071R has a lot more breath left in it, so I could easily go for much more power.

As for internals, I really don't trust the imported engines, regardless of compression testing, leakdowns, and all the other various preventative measures (I've heard too many horror stories). So I am definitely going to do something inside the engine, but I am not looking for anything extreme at all, I'm just looking to replace the common wear items. I'm not looking for any power gains, just simple reliability.

Also, thanks for both of those links, I have already been checking out the first one, and I'm sure the second one will be useful.




Sorry I couldn't get back to everybody who chipped in sooner, I'm on the east coast, and the last time I checked this thread it was past midnight here.

I greatly appreciate not being flamed, and the information thus far has definitely been useful. I will continue to search, but please feel free to chip in here, I would love to get some more opinions.

[Pandapants]

I've considered it, but that just kills part of an S-chassis's spirit in my opinion. Not to mention they're pretty heavy engines and can disrupt weight distribution, so it's just not an option for me.


They weigh just about the same as an sr swap, way less than an rb or ka.

[kilcourse64]

Miss-post. I would delete it if I knew how.

[kilcourse64]

They way just about the same as an sr swap, way less than an rb or ka.

I've read information that has lead me to believe otherwise. Roughly 500lbs for an SR20DET engine and transmission, as opposed to the 700lbs of an LS1 engine and transmission. I believe the transmission alone from the LS1 is almost 200lbs, so that definitely adds some weight to the equation. Either way it's just not for me.

[Pandapants]

i saw it weighs ~450lbs. thought it included tranny, my bad :/

[kilcourse64]

i saw it weighs ~450lbs. thought it included tranny, my bad :/

No worries, I believe you're pretty close if you're referring to the LS1 alone weighing 450lbs. An SR is a bit more than 350lbs if I'm not mistaken. The real difference between the two seems to be in the transmission weight, that T56 is pretty heavy. LS1 equipped S-chassis are definitely very capable, they're just not my cup of tea.

[95KA-Turbo]

The motor set isn't 700 lbs LOL.

I can pick the transmission up by myself. I highly doubt thats 200lbs.


Its incredibly well documented that overall you'll gain at most 70lbs from a LS1 swap. Since the majority of the added weight is in the transmission you keep the 50:50 weight balance of the car.








320whp + responsive =/= a 4-cylinder turbo motor period.

[s14_sr20_silvia]

320whp + responsive =/= a 4-cylinder turbo motor period.


A 4 cylinder turbo might not be as "responsive" as a LS-x, but a 2871R is exactly a slouch. Also I agree with the OP about losing the original 'spirit' of the S-chassis. Not that the LS wouldn't be awesome in a 240 it just isn't for me.

I'm eventually shooting for the same goal 320-350whp, and I plan on using: GT2871R (64 A/R), 740cc, ROM tune (Enthalpy or JWT), 264* cams, valve springs etc., ARP head studs, and stock bottom end. If you're more comfortable with forged bottom end and you can afford it go for it.

[kilcourse64]

The motor set isn't 700 lbs LOL.

I can pick the transmission up by myself. I highly doubt thats 200lbs.


Its incredibly well documented that overall you'll gain at most 70lbs from a LS1 swap. Since the majority of the added weight is in the transmission you keep the 50:50 weight balance of the car.



320whp + responsive =/= a 4-cylinder turbo motor period.

I didn't say that the motor weighs 700lbs, I agreed with pandapants that the motor weighs about 450lbs, and according to Hot Rod magazine the motor weighs 430lbs, so we weren't far off. Post #10.

ls1 weight - LS1TECH (http://www.ls1tech.com/forums/new-ls1-owners-newbie-tech/242392-ls1-weight.html)

I admit I was way off on the T56, I thought I had read somewhere that it was around 180lbs, so I rounded it to 200, but according to the post below it is 125lbs (Dry weight and clutch-less I'm assuming). See post #4, but also check out post #5 (GM state that a fully dressed LS1 is 497lbs)

http://www.ls1tech.com/forums/small-block-big-block-chevy-
specific/264150-weight-ls1.html

So if we average GM's LS1 weight with Hot Rod magazine"s LS1 weight, (to give you the benefit of the doubt) you get 463.5lbs to be exact. Now a dry and clutch-less T56 weighs 125, so if we total this up we get 588.5lbs. If we go with what GM specifies the LS1 to weigh, you get a total of 622lbs, and this is with a dry and clutch-less transmission. I said that the combo would be somewhere around 700lbs (for sake of using a round number). So my rough approximation was off by 75lbs.

A complete SR20 including gearbox, clutch, etc weighs 477.3lbs. Post #21.

sr20det weight... - FreshAlloy.com Forums (http://forums.freshalloy.com/showthread.php?t=7490)

So there's about a 100lb difference between the two, more like 150lbs if you go with GM's numbers. So I think that you were pretty close when stating that you would gain 70lbs from an LS1 swap.

Regardless, the balance of the car is disrupted, however slight it may be. It's not just the weight of the engine, but where it sits, it's length, depth and all of that. What really bothers me is the simple fact that it's a V8. I wouldn't do this swap, so we can end the discussion of this topic. I do appreciate the thought though.

Also, not all 320whp four cylinder turbo engines are responsive. That's a very generic statement. My friends 300whp EVO III 16g WRX feels dull and unresponsive below 3500rpm and his car was professionally tuned. The boxer engine is notorious for having more torque than other 4 cylinders, so the SR20 worries me. I've also driven an S14 with a stock redtop SR20DET and found the turbo to be very intrusive on the powerband, but this could have had something to do with the tune.

Basically I just want a responsive and reliable SR. Ideally I would like 350whp, but 320whp will be fine for the sake of reliability. Please, I would really like some opinions.

[kilcourse64]

A 4 cylinder turbo might not be as "responsive" as a LS-x, but a 2871R is exactly a slouch. Also I agree with the OP about losing the original 'spirit' of the S-chassis. Not that the LS wouldn't be awesome in a 240 it just isn't for me.

I'm eventually shooting for the same goal 320-350whp, and I plan on using: GT2871R (64 A/R), 740cc, ROM tune (Enthalpy or JWT), 264* cams, valve springs etc., ARP head studs, and stock bottom end. If you're more comfortable with forged bottom end and you can afford it go for it.

I appreciate the contribution, it seems that the GT28 is the way to go for this kind of power. I don't plan on messing about with the bottom end, I'm just looking to replace the common wear items and all of the various gaskets required in a rebuild.

From what I understand, SR20 bottom ends are pretty solid, but if someone can tell me otherwise and can offer a solution to the problem I am all ears.

I'm personally going to stay away from cams just because they add a bit of lag, but valve springs do seem like a good idea. Does anybody know if they are a common wear item?

What should I replace! I'm looking for reliable, not bulletproof. Any help is useful.

[4-20sx]

that gt2871r threat is VERY useful for you.

320 hp thats relaiable.

gt2871r + cams + injectors + ROM tune + 17psi boom boom bom! ur good to go

[kilcourse64]

that gt2871r threat is VERY useful for you.

320 hp thats relaiable.

gt2871r + cams + injectors + ROM tune + 17psi boom boom bom! ur good to go

Thanks for the input, sounds like this is the common route.

[whiterps13]

I know youre worried about reliability and what not, but that doesnt mean you need to start digging into internals. If anything, go for an s15 SR with lower mileage, newer production, and a 6 speed. Broadfield has been putting down 400+ hp and 300+ torque on stock s15 internals reliably for a while now.

In fact, his s15 motorset is for sale at the moment so that might be a great option for you. Slap on a decent manifold, a mild turbo, and get a -good- tune and you will be pushing 320 hp with absolutely no reliability problems what-so-ever. We have all heard horror stories, but it really makes a difference when you know the person who owned the engine has taken care of it and performed proper maintenence for the life of the engine. There is no real need to do internals until something goes BOOM.

Just a thought, might be better to save the money and put it aside for a rainy day or for other mods. PM "Broadfield" on here.

[95KA-Turbo]

I appreciate you citing your sources. I loved my SR when I had it, but when I decided I wanted ~350whp that was reliable and responsive I pulled the motor out and went with what offered me just that, a LS swap.

I can totally understand everyone is not OK with doing that swap, but I am happy to see you acknowledge its isn't super freaking heavy and that yes it does add weight to different places of the car - it moves the weight back and down in the car (those are both good things).

I was weighing out the costs between doing a minor build on my SR, going with a GT28, 720cc injectors, and standalone and it was only slightly more to do the LS so I went for it.


I am not sure how accurate this page is but it has some useful information about turbo size and power output on a lot of the Japanese turbos and you can directly compare the sizing to the stock turbos:

S13 Silvia Tuning (http://www.sr20tuning.com/japturbos.html)


If I were to build an SR I'd probably do a tomei set up, just because they're supposed to be really responsive and make good power. My friend had a GT28 and it was significantly more laggy then a stock set up - but if you're up in the higher RPMs and are shifting properly you can keep it in the powerband easily.




edit - I see you've seen cams cause lag. They shift the powerband up in the RPMs, taking away a lot of mid-range and low end. The GT28 will work better at higher RPMs so cams can allow the turbo to work more effectively. I put the Greddy cams in my old SR that were made for a stock motor and they made it sound cool but I only gained 7hp from 6000-7000rpms, and lost ~20whp from 2000-5000rpms. Thats about the time I realized that modifying a SR leads to less and less bottom end/mid-range.

[kilcourse64]

I know youre worried about reliability and what not, but that doesnt mean you need to start digging into internals. If anything, go for an s15 SR with lower mileage, newer production, and a 6 speed. Broadfield has been putting down 400+ hp and 300+ torque on stock s15 internals reliably for a while now.

In fact, his s15 motorset is for sale at the moment so that might be a great option for you. Slap on a decent manifold, a mild turbo, and get a -good- tune and you will be pushing 320 hp with absolutely no reliability problems what-so-ever. We have all heard horror stories, but it really makes a difference when you know the person who owned the engine has taken care of it and performed proper maintenence for the life of the engine. There is no real need to do internals until something goes BOOM.

Just a thought, might be better to save the money and put it aside for a rainy day or for other mods. PM "Broadfield" on here.

This is what I was initially considering, but after reading about the speed sensor relocation requirements, the fact that the wiring harness is completely different to the S13/14's, and the weak 6 speed I was turned off to the idea.

I appreciate your information, and letting me in on the availability of Broadfield's S15 motorset, but I'm going to hold off on purchasing anything until I know exactly what I want.

I appreciate you citing your sources. I loved my SR when I had it, but when I decided I wanted ~350whp that was reliable and responsive I pulled the motor out and went with what offered me just that, a LS swap.

I can totally understand everyone is not OK with doing that swap, but I am happy to see you acknowledge its isn't super freaking heavy and that yes it does add weight to different places of the car - it moves the weight back and down in the car (those are both good things).

I was weighing out the costs between doing a minor build on my SR, going with a GT28, 720cc injectors, and standalone and it was only slightly more to do the LS so I went for it.


I am not sure how accurate this page is but it has some useful information about turbo size and power output on a lot of the Japanese turbos and you can directly compare the sizing to the stock turbos:

S13 Silvia Tuning (http://www.sr20tuning.com/japturbos.html)


If I were to build an SR I'd probably do a tomei set up, just because they're supposed to be really responsive and make good power. My friend had a GT28 and it was significantly more laggy then a stock set up - but if you're up in the higher RPMs and are shifting properly you can keep it in the powerband easily.




edit - I see you've seen cams cause lag. They shift the powerband up in the RPMs, taking away a lot of mid-range and low end. The GT28 will work better at higher RPMs so cams can allow the turbo to work more effectively. I put the Greddy cams in my old SR that were made for a stock motor and they made it sound cool but I only gained 7hp from 6000-7000rpms, and lost ~20whp from 2000-5000rpms. Thats about the time I realized that modifying a SR leads to less and less bottom end/mid-range.

I really appreciate this info, it's a great help, and is exactly the sort of stuff I'm looking to hear. Real info, from real SR owners (Or previous owners).

I do realize that for what I want, an LS1 is the ideal option, and I have considered it, especially due to the fact that before my turbo experience I was a 100% n/a guy. Nearly all of the best cars I have driven were n/a: Miata, AE86, S2000, M3, 350z.

I know it doesn't make sense, but for some reason a V8 in an S-chassis just doesn't sound right to me. I think of heavy and unbalanced muscle cars and the exhaust note is like hearing opera music from Eazy-E's mouth.

Maybe I can get over my affliction with the V8 transplant, but for now I plan on sticking with the SR, and I greatly appreciate your help in my pursuit.

[HayaiSaru]

Look into the new borg warner turbos.

[kilcourse64]

Look into the new borg warner turbos.

Great advice, I am definitely liking what I'm seeing. Somewhat pricey, and they're yet to really be tested, but they do look very promising. Nice contribution.

[SmogSUX]

Ls1...Done and done
A relaible 300 to 350hp all day long.:rl:

^This. Ls1 bone stock=reliable, responsive, good gas mileage.

[kilcourse64]

^This. Ls1 bone stock=reliable, responsive, good gas mileage.

I appreciate the idea, but if you read through this entire thread, you'll see that I'm planning on sticking with an SR. The LS1 does seem to make the most sense though.

[Om1kron]

come to zilvia,
search new posts on zilvia
see guy with under 10 posts asking how to build a reliable 350hp motor
probably will never build motor after having questions answered
time wasted
bandwidth wasted
mission accomplished.

Seriously these threads should be an instant pink for not reading the posting rules.

[Y0SH]

For the longest time i hated the idea of a LSX swap. Then i read 95KA-Turbo's build thread and ever since have been wanting to do a LS swap. good power and reliable.

[s13dan]

Garrett's gt28rs,550's , tuned ECU and Z32MAF, DONE. Easy 320hp and much more responsive then any other similar turbo set up. Makes power sooner too, so it proves to be faster than guys making more power at much higher revs.

[kushlivin]

come to zilvia,
search new posts on zilvia
see guy with under 10 posts asking how to build a reliable 350hp motor
probably will never build motor after having questions answered
time wasted
bandwidth wasted
mission accomplished.

Seriously these threads should be an instant pink for not reading the posting rules.
DONE and Done... Nuff said thank you

[GripTerror]

just go with the v8 you'll be happier in the long run and more reliable/less worries......... get a few lightweight parts like frp hood, fenders, etc... and stiffer front springs or something and you'll balance it all out woopie do

[herbieS13]

KA-T torque monster but if u wanna do SR, punch out those sleeves and get some 87mm pistons since youre gonna have a shop build your motor, a 2871r is ideal for the power range you have in mind, if you dont plan on going much higher in power 740cc injectors will give you what youre looking for with some wiggle room. i personally use PFC Djetro w a 3bar GM map sensor so no MAF

[handinpants]

I will be paying for someone to install these parts. But basically I am looking for a torquey and reliable 320whp, so what internal engine modifications do I need or would you suggest? What would your spec sheet look like? I don't need a bulletproof engine, just something reliable, as I just don't trust these older imported engines.


Now for turbo options, I've read that for what I'm looking for, ideally I should be going with a twin scroll GT3071R from Full Race, but I'm not sure that I want to drop that kind of money, so what are my options? 850cc injectors, a Walbro 255, and a Z32 MAF all seem to be common in this range as well, but if you can point me in a better direction please do.

Any and all info will be of great help.

so what you are saying is, you don't trust non american engines, your not mechanically inclined and you don't have a whole lot of money to spend, but want the most bang for the buck. is that correct?

If i knew ahead of time, how much i had spent on my sr to make it have 320whp, I would of just gotten a chevy lsx swap in my car, and maybe a bag of sand in the trunk to keep the wheels on the ground, reliable, torquey, oh i from what i read the ls1 weighs 40lbs more than a ka24... it will not offset the weight balance of the car, all that can be adjusted in the suspension set up, plus when it comes to cars, the hardest place to shed weight is in the drivers seat.
gas is cheaper in your area than it is here,


oh and your fear of imports came from audi's awesome electral system

[kilcourse64]

come to zilvia,
search new posts on zilvia
see guy with under 10 posts asking how to build a reliable 350hp motor
probably will never build motor after having questions answered
time wasted
bandwidth wasted
mission accomplished.

Seriously these threads should be an instant pink for not reading the posting rules.

I'll view this as inspiration to follow through with what I have mentioned in the above posts.

For the longest time i hated the idea of a LSX swap. Then i read 95KA-Turbo's build thread and ever since have been wanting to do a LS swap. good power and reliable.

The idea has been growing on me, and 95KA-Turbo has been very helpful in this thread.

Garrett's gt28rs,550's , tuned ECU and Z32MAF, DONE. Easy 320hp and much more responsive then any other similar turbo set up. Makes power sooner too, so it proves to be faster than guys making more power at much higher revs.

Yes, from what I've read, and what people seem to be posting, a GT28 and various other supporting mods seem to be the most common way to achieve what I am looking for.

DONE and Done... Nuff said thank you

See my response to Om1kron

so what you are saying is, you don't trust non american engines, your not mechanically inclined and you don't have a whole lot of money to spend, but want the most bang for the buck. is that correct?

If i knew ahead of time, how much i had spent on my sr to make it have 320whp, I would of just gotten a chevy lsx swap in my car, and maybe a bag of sand in the trunk to keep the wheels on the ground, reliable, torquey, oh i from what i read the ls1 weighs 40lbs more than a ka24... it will not offset the weight balance of the car, all that can be adjusted in the suspension set up, plus when it comes to cars, the hardest place to shed weight is in the drivers seat.
gas is cheaper in your area than it is here,


oh and your fear of imports came from audi's awesome electral system

Ok, first off to answer your question of whether you are right about your initial assumptions, no you are not. I don't consider myself mechanically inclined, but I know enough to install a set of coilovers, remove and install a turbo-back exhaust systems, and swap differentials among other things. I trust non-american engines even more-so than I do others (I am particularly fond of Japanese engines). I just don't trust the engines that these engine suppliers are selling (I've heard numerous horror stories, regardless of where you go). Also, you don't need to worry about my financial situation, if I didn't have a enough money to go through with this, I wouldn't be asking the question. Just because you have money, doesn't mean you need to blow it, I would prefer to be cost effective in my parts selection.

Now to respond to your second statement, as I have mentioned above, yes the LSX swap does have a certain allure for me, but I believe some of the S-chassis' spirit is lost in the process.

Lastly, I actually don't mind Audi electrical systems, but then again my experience only lies with B5 and B6 S4's. Now BMW's are a different story, my M3 was a bit troublesome.

KA-T torque monster but if u wanna do SR, punch out those sleeves and get some 87mm pistons since youre gonna have a shop build your motor, a 2871r is ideal for the power range you have in mind, if you dont plan on going much higher in power 740cc injectors will give you what youre looking for with some wiggle room. i personally use PFC Djetro w a 3bar GM map sensor so no MAF

Thanks man, I appreciate your insight. That might be a bit more extensive than what I am looking to do, but it is an option none-the-less, so I will check it out.

[Kingtal0n]

plz feed im trying to have some fun.

"Either way it's just not for me. "
He doesnt want the Lsx engine, or any V8. he wants the S-chassis engine that it was designed for: SR20DET. Personal preference, both great engines.

That said, with the sr20det in mind, you only have one option:
S15 SR20DET, 100% OEM
or
S15 SR20DET, GT2871r .64 / 550+

And thats it. There is nothing else worthy of providing the sr20det power you crave along with the cookie cutter reliability status, along with the pre-determined steps and parts necessary to do the job available all over the internet, and especially here.

/thread

and just in case you are thinking of posting more questions i already thought of the answer:

#1 Anything else is a deviation from reliability or non-cost effective
#2 because you want to do only oil changes and drive it every day until you wreck it
#3 you said you didn't want to try the LSx. But if you did, I would recommend that instead, obviously. What? an extra 4L of displacement for like 250~ possible extra pounds? rofl i would take 2 extra sr20det engines under my hood for an extra 250lbs... am I crazy?

[teh smithers]

Please stick with the SR! I share your original sentiments of "ruining the S-chassis spirit" with a LSX. So, to hit your projected 320-350whp...

-You can keep the stock bottom end. It can handle what you're looking to throw at it. If someone is taking the motor apart though, definitely get new bolts/studs to be safe.
-The optimal turbo would probably be a GT2871R. If you wanted a little more response, you could run a GT28RS, but it will take more tuning to hit your power goals.
-740cc injectors will be plenty.
-GET A GOOD TUNE. Can't stress that enough.

[guitaraholic]

I've been looking into the Borg Warner EFR series. Heck, even the smallest one will flow 45lb/min (~450hp) and from what I've seen on a few scarce dynos it will be as responsive as a disco.

The one dyno I seen of a 6255 on a 1.8 liter. It was at full spool at 3000rpm. Even had 3psi by 1900rpm. It also made 260whp at only 10lbs of boost, very impressive for a 1.8liter. From what I have heard they have already dropped the 6255 in favor of the 6258 because spool is identical but the 6258 has about 100 more HP potential. Heck 320whp the turbo will be well into its efficiency zone with lots of room to grow. I only see a few disadvantages of this turbo.

---It's Expensive
---Custom Downpipe (not too big a deal)
---Slight mod to get it to fit stock mani (I believe something to do with the water pump)

But it would be one hell of a sleeper turbo to. People look down and see a "baby" turbo, yet you can crank the boost and hit close to 400whp.