Let's talk turbo!

So, I know just the basics on turbo's and turboing a car. If I wanted a turbo, would I need a piggy back chip and boost controller? Would I need an intercooler if running low boost? Talk to me, tell me some stuff that I probably don't know. You can be as technical or untechnical as you like. Does boosting wear down the cylinder walls or the engine more than NA? Pro's and Con's? I know something about turbo lag but minimal about exhaust/turbo's.

 

Noah,

If your just looking for some fun, I'd go with NOS, that way you dont have to deal with all that hardware, and having to speed a whole bunch of money to get and install it and tune it.

NOS is fun and is cheap, just dont get carried away.

Chong

 

Yeah, I found a couple of kits for $510-$550. So, what do you know about NOS?

 

You'll need a J&S Safeguard to control engine knock (ignition before spark plug sparks). Running low boost as in <5psi you won't need a intercooler, but you could if you wanted to be on the safe side. I don't think boosting will put more wear on the walls because basically it's just moving down.

Snails are slow. They're a car's friend and can be a car's enemy. Tuning makes a car happy with the snail. You have 2 snails turbine housing and compressor housing. The pretty silver one is the compressor housing, usually the darker snail is the turbine housing. The compressor housing it where the air is being drawn in where as the turbine housing is there the exhaust flows through it. Then there's the wastegate, your boost limiter. This keeps the turbo from over spinning via letting out exhaust gases via little vavle in turbo or an external wastegate, which is mounted before the turbine.

Compression ratio plays a big role on how to turbo your car. Running 10:1 (common on most NA cars) you'll be able to boost to 12psi assumming good tuning. The most relieble would be near 7psi or less in the long run. The down side is that you'll have to run high octane to reduce detonation. It also plays a role in torque curve. The higher the compression ratio, the sooner the torque peeks and also a flatter torque curve. Lowering the compression ratio will cause the torque curve to peak higher in the rpm range and also lower the curve in the lower range of the powerband/rpm.

Lowering compression ratio helps reduce this knock, detonation, thus allowing you to run regular pump gas.

A turbo gets hot, it needs cooling. Oil lines run to the turbo to cool it and the like. I don't think raditaotr fluid goes to it, does it not?

There's more, but someone can add more cause I have to go to class.

 

Thanks Fue! I already have to run Premium unleaded, are you talking HIGHER octane than 91-93? I hear that my stock compression is already 15:1 so they say that I shouldn't boost more than 4-5 Lbs more. Why? Is this where they talk about a "built" engine? I don't know what a built engine is. Is it like sleeves and titanium lifters and valves springs and the like? Fifteen lbs. per square inch doesn't seem like alot of force considering my tires are RUBBER not Metal and they can take 44Psi! :???::???: It doesn't make sense to me. Also, can running NOS (for instance setting it to open at Full throttle), adversly effect the cars longevity? Come on guys you know I am a sponge for knowledge! Talk to me.

 

Is a wastegate the same as a BOV?

 

Your car's compression ratio is definitely not 15:1. Depending on what year it is, it's 9.5 or 10:1 (there's one oddball year in there with 9.7:1 but you get the idea).

Like Fuji said, a wastegate is to allow exhaust gasses to bypass the turbine and avoid overspinning. A blowoff valve keeps pressurized air from entering the engine when you are off the throttle (shifting). On Subarus this air gets vented back into the intake tract instead of going out to atmosphere (which gives you the annoying POOOSSHHHH like on the SRT-4).

A built engine is usually stronger (forged) pistons and beefier rods, maybe a balanced crank, possibly sleeved, etc. Bigger, better, stronger internals. And if you have it all apart to do that, it's worthwhile to do headwork as well.

It doesn't sound like you've seen this site, so read up:
http://auto.howstuffworks.com/turbo.htm

 

Tanx bro! I'm going to the site right now.

 

I know Fue knows alot but I'm going to go with the veteran on this one. Thanks Matt. BTW: MY GOD! Your car is sweet!! You can't even tell! That black FMIC is incredibly incognito. Wow. Ultimate sleeperoo. Are you just going to sit back and let eveyone else tell me about turbo's though?

 

blah blah, smack my gran, i'm a huge idiot

 

Joel,

That is why he is OB1.

Chong

 

no for real, i'm an idiot. i have heard the correct explanation before but in my beer-deprived over-worked under-fed state i did not retrieve it from the proper place in the grey matter.

i'm going to go set myself on fire now

 

what do u mean? are u in some kinda DO DO?

 

Try this link http://auto.howstuffworks.com/turbo.htm

 

The compression ratio does have an effect on it, Matt, but by a little bit. But yes, I agree that bore and stroke plays a much greater role though.

 

Hehe! OB-Wan Mattobe. I started this thread, not only because I want to build on my car perse, but because I wanted to learn more about turbo's and turboing.

I checked out the Howstuffworks.com site and learned a good amount on the turbo and how it works. Also that BOV thing makes perfect sense now.

I wish I had the money to turn my car into a monster, but unfortunately, I don't.

My plan is to give it some extra power however.
Here's what I want: more 'off the line' pick-up, better flowing, more aggressive sounding exhaust (I have <font size="3">4</font id="size3"> cats), probably stiffer brakes (SS-lines) that don't warp (cryo'd rotors), and possibly stiffer suspension.

AND I want to keep it a daily driver.

Question: Theoretically, (Since I have 'True Dual exhaust' and dual throttle body's) could I put two, dual stage twin turbos on either side of the engine?

I can do the brakes, I now know enough about those.
I need to learn more about suspension.
I need to learn more about power mods.

 

Noah,

No offense, but I highly recommand learning how to drive first, so you can tame that car before getting too wild. I really dont know what your goal expectations are, but you should get with someone who has a reasonable power band that your trying to achieve and get a feel for how it really is first. Things get really dangerous when you dont know how to control your ride.

And besides you dont wanna spend all that money for something your not sure what your going to get. That is why I suggested NOS. Maybe get the car to breath better and flow better. Maybe get that thing out to a track event, that way it will give you a good idea what kind of ride quality you would want for street.

If your interested MAC has some pretty good inexpensive Autocross schools class that take place at the begining of each season, but you can still go to their events, there is a lot of nice people there that are willing to help out newbies. The next event is at Valley Fair, and its nothing like C-Spot (C-Spot Run, that is why they call it that). I always had a lot of fun doing these events til I moved over to Road Racing, but that is NEXT.

Enjoy!


Chong IMO $.02

 

Yes, I am definitely going to get some lessons. If not actual school/classes, definitely hit the track as a novice and learn the ropes. I have a good friend who used to live in Japan and did drifting over there. He's got a rex and let's me drive it whenever we get together. He's been teaching me stuff too. I need to look into it though. MAC you say Chong? Cool.

This is why I ask you guys.

Very humble of you Matt. I don't have any track experience nor do I have high speed experience (aside from the expressway). But, nothing like high speed maneuvering, chicane's, slolum. So, I need to learn that for sure. I also know not to push it too far though, I'm not trying to show off, I'm trying to learn. Family's too important; they need me alive and conscious.


Oh, it's that Dk. green <font color="green">Subaru SVX </font id="green">that was there on Friday. I used to drive the Lt. green Legacy Wagon.

I still have that question about NOS and the longevity of the engine unanswered.

NOS:$550 50-75hp

Small turbo w/o intercooler $3,900 60-70hp

:???:

 

Noah,

I think your on the right track, you will be glad one you have done all that you have listed above (training),someday your family and your live may depend on your highly skilled driving skillz.

As far as your NOS question, I still recommend it first, reasons, its inexpensive, and is safe if you learn to use it wisely. Honestly I dont know enough about this subject, other than I have friends who love running this on their cars. As far as the wear and tears it the same as anything else. There are many safety features that can be added to a NOS system. The only down fall is that you have to recharge the bottle and you cannot use it at sanctioned events.

I'm going to refer you to the same websites, that way you can get the facts straight.

http://auto.howstuffworks.com/question259.htm


"How does nitrous oxide help an engine perform better?

This Question of the Day talks about how sodium chlorate acts as a way to store oxygen. You release the oxygen in sodium chlorate by heating it. It turns out that nitrous oxide (N20) works exactly the same way. When you heat nitrous oxide to about 570 degrees F (~300 C), it splits into oxygen and nitrogen. So the injection of nitrous oxide into an engine means that more oxygen is available during combustion. Because you have more oxygen, you can also inject more fuel, allowing the same engine to produce more power. Nitrous oxide is one of the simplest ways to provide a significant horsepower boost to any gasoline engine.

Nitrous oxide has another effect that improves performance even more. When it vaporizes, nitrous oxide provides a significant cooling effect on the intake air. When you reduce the intake air temperature, you increase the air's density, and this provides even more oxygen inside the cylinder.

The only problem with nitrous oxide is that it is fairly bulky, and the engine needs a lot of it. Like any gas, it takes up a fair amount of space even when compressed into a liquid. A 5-liter engine running at 4,000 rotations per minute (rpm) consumes about 10,000 liters of air every minute (compared to about 0.2 liters of gasoline), so it would take a tremendous amount of nitrous oxide to run a car continuously. Therefore, a car normally carries only a few minutes of nitrous oxide, and the driver uses it very selectively by pushing a button."



The other benefit to buying a NOS first is that if you decide to upgrade and get a Turbo Charger kit afterwards you can still use the NOS for additional power or just to help with cooling the air.


"Mac" www.mnautox.com

Enjoy,

Chong

 

you can definitely turbo a car for cheaper, and i would say get used mechanical stuff, as it doesnt matter too much. But DO NOT skimp on engine management, it really is all about tuning.

i dont know who said you have 15:1 ratio, i wouldnt listen to them very much anymore.

A few have turbo'd the EG33 i believe on the boards, so try a search on NASIOC.

also check out www.forcedairtech.com

he makes a kit for the SVX and his products are top notch, only draw back is he needs the car to do it.

if you want to go the FAT route let me know i may be able to get you a discount, but more on that later....

hehe, if i get good at welding i could fab something up for you

although, im sure there are others already here that could do it much better, thing is im crazy enough to try.

If you are serious about it, i would look into what engine management you can use first and foremost, it could be as easy as getting an RS link plus, but maybe not since you have the six cylinder engine.

lots of others are more experts than myself, but i have learned a great deal in terms of aftermarket turboing from my own car, so feel free to ask

Joel-its the 99 RS's that have the 9.7:1 and manifolds that directly fit wrx injectors making them the desired choice.

Ben

 

Yeah, I'll try to make it. We'll have a good discussion.