A/R in turbo's?

[DeleriousZ]

anybody know what the perfect a/r would be to have on a turbo for a newer gsr motor? can anyone tell me what it is?? lol. i am totally clueless about this compression size housing and all that stuff, no idea what the good sizes are to run on a b18c1... i heard the GT35R was a good turbo, but i prettymuch have no idea what this means. i'm looking for something that's ball bearing for sure.. not more than 1500 american tho as i am attempting to stay on a budget, as well as me being canadian, i gotta pay like a whole bunch more... anyway i'm starting to ramble.. would anyone care to inform me about turbo's?

[duplox]

sure. Just give me some detailed plans of what you're going to do to your engine, and I'll tell you what you'll need. this is what I need to know:
Bore
Stroke
Head type(SOHC/DOHC, valve sizes(4 or 2 valves per cyl?)
RPM range
Compression ratio
rate your intake manifold and exhaust manifold's flow capabilities on a scale of 1-10, since i doubt you have flow numbers. 1 would be poor flowing stock, 10 would be full race. I'll bullshit it from there.
do the same thing for your heads intake and exhaust ports.
Intercooler? What kind(air-water, air-cold water, air-air... and how good is it?)
Water/alky injection?
How much boost?
I'll give you what turbo would work best, my recommendation on specs for a cam, a hp estimate, and what size fuel injectors you need.

[boosted331]

A/R is a ratio.

A = area of throat at intake
R = radius of scroll in housing

Basically a smaller A/R ratio makes the turbo spool quicker, but becomes more of an exhaust restriction at higher RPM's, limiting top end power. A larger A/R ratio promotes top end power, at the expense of low-end boost response. A .63 A/R T3 housing gives you a nice mix of spool and top end power for a stock honda, a .48 is too small, and a .82 is too big for most mild motors.

[DeleriousZ]

well i'm pretty sure i'm gunna stay safe and not do anything to the bore or stroke, but it'll be on a 96 or 99/00 gsr engine (not sure yet) with gsr heads
probably take the cr to 9.0ish, definitely go with a stainless steel tubular exhaust mani, maybe a new intake mani if it's needed.. as for the ports i've got no clue (suggestions) as for the intercooler, whatever the best is for the best price, so most likely the one in the middle.. if it's crucial i'll go all out, stock injection (just plain 93 octane pump gas) most likely 15 psi.... that's about all i know about the engine, as i am a n00b to engines (i'm only 18) so i'm totally open to any suggestions on setups and such.. looking for 15 psi as a solid number tho.. and a for sure on the pump gas... doing a rebuild tho, so i might be replacing the heads or something... i dunno, it's all so overwhelming

[GWInquisitor14]

Alright w/ that 15 psi, have fun blowing your motor. You're gonna have to definatly lower the compression to 9.0 like you said but w/ a stainless steel exhaust manifold, you'll crack that in an instant. Go w/ the cast iron cuz the steel is just welded pipes, it will crack easly unless this is a race application only. You will FOR SURE NEED NEW INJECTORS. You will run way too lean for that much boost, you'll definatly overheat you engine and then bye bye GSR motor. You will definatly need to resleeve your block, get stronger rods and probably some stronger head internals likke valve springs and retainers. Since GSRs have more compression than the LS, you will only be able to run 7-8 psi, at best. If you do anything to the bore or stroke, that is a huge process that requires a lot of work if your gonna turbo also, not the work of a noob. Remember you will still need shit like a wastegate, BOV, intercooler piping, oil lines for the turbo, Id susgest getting a Hondata and not all the FMU shit, its much cleaner and easier to have all the management in one thing. Its a little bit more expensive but you will be thanking me later. You will probabyl need a new fuel pump and regulator if you want 15 psi. Id susgest starting out basic and run just 7 psi then upgrade later and boost the pressure. Replacing the heads wont do much in a rebuild unless they are stronger. Sorry for being so harsh, just that I'm barely 17 and dont consider myself a noob. My turbos goin in this summer once ive gotten all the parts. For a noob, id susgest getting a kit.

[duplox]

air-cold water is going to be pricey, big and complex unless you build it yourself, and it will still take up lots of space and be complex and still cost more than an air-air unit. I built one for drag racing. It is hands down the best style intercooler for drag racing, but it ain't cheap or simple. For a street car, air-air is probably best. Heads - performance heads will definately help make more power. Do GSRs have aluminum heads stock? if they're iron, then aftermarket aluminum heads will help a lot. they allow more boost by dissipating heat much better than iron which prevents detonation.

As for my recommendations/predictions:
can't really help on cam specs too much, since I dont know valve sizes/port flow #'s for the heads... But based on my educated guesses, this is what i recommend:
Intake:
centerline : 110* ATDC
duration @ .050" : 205
valve lift : .442"
Exhaust
centerline : 116* BTDC
duration @ .050" : 210
valve lift : .476"

113* lobe separation, 3.0 advance

I estimate 219 ft/lbs @ 4750rpm, 262hp @ 7250rpm

For a turbo, I'd say a T3 "50" or "60" trim... I'd say a .42/.48 A/R t3 may be a bit small and restrict top end a bit. a .48/.60 would be better. These came stock on the late 80s Ford Thunderbird Turbocoupes, and can be found frequently on ebay. Here is a new one on ebay : http://cgi.ebay.com/ebaymotors/ws/eB...tem=2467730367

38lb/hr injectors, 40s are more common and would be best bet in case you ever want to increase boost.

[GWInquisitor14]

Ya this guys talking about boring and stroking his engine and port and polishing it, yet he doesn't know a lot about cars, as we can tell, BTW, i just wanted to say that "modding" cavaliers isn't stupid, i know a kid w/ a sweet ass Z24 2 DOOR, so its a coupe not a sedan, making it not a family sedan. His car is fast as hell and has amazing body work, shaved trunk including the half of the tail lights on the trunk, CF hood, z3 fenders, "drift" spoiler and repainted black by himself

[DeleriousZ]

i think what i meant to say was that i'm a n00b to honda engine's.. i've rebuilt the odd 350 small block in my day, but that was a few years ago. as for bore and stroke, i never said i was going to do anything to it, and if you were to read some of my other threads you would realize that i know about most of the internals stuff, especially the pistons/rods business. as for sleeving the block, i've asked the question elsewhere and was told that i definitely didn't need to get it re-sleeved, as people are running 15 psi on stock gsr sleeves with no problems at all. for the fuel system i'm for sure getting new injector's/rails/fuel pump (that should have been a given) as well as the aem ems (bit more pricey than the hondata but it hooks right into the obd II configuration, and has way more options. as for all the extra's on the turbo, eg/ wastegate, bov, all that stuff.. well no sh*t!? it's not like i'm 12 years old. the only thing i'm still kind of in the dark about is the stuff to do with the heads, and what type of *aftermarket* turbo would work best on my *swap*. as for the stainless steel exhaust manifold, i've been told that they are much stronger than the cast iron manifold, and can handle high temperatures much better. just as a side note i have already put about 500 hours of *research* into this turbo/engine swap thing, so i mostly know what i'm doing.. oh and by the way duplox thanks for the help but right now you're speaking jibberish to me, give me a few hundred more hours of research and i'll know what you're talking about and as for intercoolers.. know any good places to go to that's relatively close to west coast canada?

cheers

[GWInquisitor14]

Sorry man, but you were pretty hazzy on your post. Sounded like u were one of those kids who like to name off performance parts like no other yet not know a thing about em or even what they do, they just the names from F&F and 2F2F. but u did say stock injection. Yeah id rather have the AEM unit also, its just like 3 times the price of a hondata. But wow 500 hours, thats a lot, maybe a lil overstreched. Myself, I'm between the Garrett and Turbonetics...I'm leaning towards Garrett because they put more technology into their turbos. Ive heard bad things about GReddy. Heres a great site for info on DIY head port and polishing
http://www.sa-motorsports.com/diyport.htm
With a turbo car, you dont want to port your heads to the fullest unless its a large race application. The polish is more important. If you have a very large port, the air and fuel dont mix well and dont burn well. You'll still get HP gains but not as much as you will a lighter one. That site pretty gives the just of what you want on a turbo application. The cast iron is definatly stronger for a daily driver car, ive talked to a metals expert. On the steel manifold, the tubes are just welded together and aren't as strong as one solid piece of iron. The steel manifold is better if you wont be daily driving the car because it wont heat up as much. Iron is less likely to crack when it is heated up from the exhaust then cooled when the car is off than a steel manifold is. Even look at the prices, cast iron manifolds can run as much as $800 while most steel manifolds are less than $200. THe only thing steel manifold benefits from is equally balanced piping. A good way to find out what your timing should be set at, is dyno tune it. With a stock motor, its no big deal but w/ the turbo you'll want the timing set up but i asume that after 500 hours you know that when you dyno tune it, you'll be able to adjust you cam specs also.

[DeleriousZ]

yeah sorry about that post man.. it was like 2 in the morning and i had school the next day so it was a little rushed (no spring break GRRRR) but yeah that site looks like an awesome read, yeah, 500 hours does seem like a lot... but when all you do is come home from school and sit down at the computer for a while.. it adds up quite quickly, as for the cast iron manifold thing, that'll take quite a bit of convincing my friend, cause he was dead set on making me one (works at a machine shop) but i can see where you're coming from with the strength issue.. but are you talking about the actual pipe or where it's welded? yeah, and i must agree that people who watch the f&f movies and come on here and talk like they know what they're saying are WANKERS, but that's a whole different story.. and i'm not going to get started on that. looks like i've got a long few nights ahead of me... i wanna get this turbo issue worked out for when i put my rims on..(saturday) w00t w00t!! lol... yeah i'm stoked.. just had to get that out
although.. i'd rather have done some performance stuff before i got the rims, but if i didn't buy some new rims/tires my baby would be up on blocks when it's time to take off the winters (stupid snow).. yeah i'm rambling.. and it's time for work
cheers

[GWInquisitor14]

Ya that sounds EXACTLY like me, i come home at 3 and sit on the computer till 10 looking at all kinds of car stuff. Especially i have a friend whos set on helping me make intercooler pipes outta steel and not alunimum cuz steel is stronger, hes a big metals nerd....spends 4 hours a day at school in the metals room doing random shit. I haven't even put my turbo kit in yet, im reading as much as i can and making as many posts as possible to make sure i know exactly what I'm doing.

[boosted331]

Originally Posted by GWInquisitor14

The cast iron is definatly stronger for a daily driver car, ive talked to a metals expert. On the steel manifold, the tubes are just welded together and aren't as strong as one solid piece of iron. The steel manifold is better if you wont be daily driving the car because it wont heat up as much. Iron is less likely to crack when it is heated up from the exhaust then cooled when the car is off than a steel manifold is. Even look at the prices, cast iron manifolds can run as much as $800 while most steel manifolds are less than $200. THe only thing steel manifold benefits from is equally balanced piping.

For one, a cast manifold is MUCH MUCH more prone to cracking than a well built tubular header. Since you're only making one header for hondas it is still affordable for most people to buy a 321SS header, which pretty much will not crack. The "horror stories" you hear of headers cracking are cheap 304SS or mild steel headers built from thin-wall steel that is MIG welded instead of tig welded. I think you have the prices mixed up here, the highest priced cast manifold on the market for hondas right now are inlinepro's cast manifolds, which are around 480 dollars. A good stainless steel equal length (Only companies I would consider buying from if I were to buy a new manifold would be Full-Race, Lovefab, or Super-T) is going to be around 800-1000 dollars, provides much faster turbo spool and, if you buy a good manifold, they have very good wastegate positioning to practically eliminate boost creep. Go look at drag manifolds, the wastegate only bleeds off exhaust gas from ONE header primary, and that manifold is very prone to boost creep.

[duplox]

http://www.sdsefi.com/techheader.htm

Thats all you need. Show that to your friend, it will be very helpful for him.
Notice this: "This thickness is necessary with non-stainless tubing for longevity at the high temperatures encountered. Standard mild steel header tubing will quickly self destruct if used for a turbo header"

[DeleriousZ]

kick ass site duplox, mega props to you man, that's gunna be soooo helpful!! and yeah i was pretty sure the stainless was stronger (properly constructed that is) so you recommend constructing the manifold out of 321 stainless steel boosted? is there anything better than that out there (that's practical of course)
as for you GW, you sound freakishly exactly the same as me
but i'm off to party it up.. happy st. patrick's day guys

[boosted331]

Originally Posted by duplox

http://www.sdsefi.com/techheader.htm

Thats all you need. Show that to your friend, it will be very helpful for him.
Notice this: "This thickness is necessary with non-stainless tubing for longevity at the high temperatures encountered. Standard mild steel header tubing will quickly self destruct if used for a turbo header"

If you're going to build a header like that, you might as well buy a mass-produced cast one. That header doesn't have a merge collector, which right there pretty much nullifies all the benefits from a tubular header.