Some Questions

Forgive me for being a lil slow, but I'm really just now getting into forced induction so I would like to know as much about the extra details as possible (I read your lesson plan and it was very helpful).

I've read a lot on it from manufacturer pages and whatnot, but it wasn't explained well, what is the difference between a super-sequencial bov and a "normal" one?

If an intercooler must be positioned in front of the radiator, how is it that there are top mounted intercoolers?

Why do stock (turbo) cars come without a turbo timer or boost controller (I kinda get the reason for the lack of boost controller... but the turbo timer I would figure would be a requirement... or maybe I have the wrong idea of what it does...)?

Hate to bothor you with these questions, I just really wanna know.

well, its a good idea to cool down your turbo...but on normal cars "Turbo beatle" the turbo is not only mild but usually not run hard. It still takes it hard from the sudden lack of oil going through it, but not as bad as a car with a T3-60trim after doin 120 down the freeway for a while.

Top mounted intercoolers have a problem with "heat soak" Heat comming from the head heating up the intercooler, making it less effective.

You have the same problem if its behind the radiator. The hot air from the radiator heats up the intercooler instead of cooling it. When its infront the air cools it, then cools your radiator.

Boost controller is for performance. It's like adding a cold air intake (in the idea that it is a performance mod that wouldn't be on a normal car.) And if most people had them, they would need to be preset and idiot proof to prevent people from overboosting.

i think hes talking about a v-mount setup. thats when the i/c sits on top and the radiator sits right under it. the whole shape is made to look like a v. its useful if your worried about overheating because it give the radiator and the i/c more breathing space, but it takes a ton of custom work to complete. ill post pics later

check ou my mad drawing skillz!!:sunglasse
http://i25.photobucket.com/albums/c88/Attiman/vmount.jpg
i think the i/c is usually angled upward a bit, but hope that helps

Turbo timers are pretty much a waste of money imho. I mean, they do what theyre intended, but why not save yourself the $100 and just let the car cool down for a minute before shutting off the car? :2cents:

btw, just fix the whole heatsoak problem and get yourself a water/air intercooler. :grinyes:

well, if you watch exactly how hard youve been and how long youve been on the freeway and calculate how long to leave it running for through that, then go for it!

I like to let the lil thing ($60 for mine) do that for me. Drive on the freeway for 2 hours, its on for about 2 min, drive around town, one min. And I can leave it running as I walk away. Peoples reactions are great too. I left it on and walked to get food, a cop was walking to his car *right next to mine* and noticed it, started lookin at it funny so I yelled out "dont worry, it will turn off in a min" and it turned off right then, he got a laugh outa it and waved.

Good stuff!

Water to air is a great way, compact and effecient.

well, if you watch exactly how hard youve been and how long youve been on the freeway and calculate how long to leave it running for through that, then go for it!

I like to let the lil thing ($60 for mine) do that for me. Drive on the freeway for 2 hours, its on for about 2 min, drive around town, one min. And I can leave it running as I walk away. Peoples reactions are great too. I left it on and walked to get food, a cop was walking to his car *right next to mine* and noticed it, started lookin at it funny so I yelled out "dont worry, it will turn off in a min" and it turned off right then, he got a laugh outa it and waved.

Good stuff!

Water to air is a great way, compact and effecient.

Your right, I cant get the analytical answer as to how long I should let it run. But I know whether I've been on it or not and I can guess as to how long I can let it sit. Chances are, I probably let it idle too long just to be on the safe side. If I've gotten into boost at all and the EGT's are high before I park it, I let it idle for about 2 mins. If its just simple cruising around, I let it sit for about a min. I've had the turbo kit for over a year now and it still treats me well. :)

good to hear someone treating their car right :)

Most I know eather have a timer or do a hard run and just shut it down.

I'll try to answer the top mounted intercooler question. it could be that they can get more airflow up there. if you look at the evo's, they have a huge hole in the hood, that id for the intercooler. the wrx at some point had a top mounted intercooler, i don't know if they still do.
as for heat soak, you could do what the wrx did and have little water jets spray onto the intercooler if it gets too hot. that way you have the advanteges of an air-air intercooler, easy to install and you don't need to replace the water, with an added safety feature to keep it from getting too hot. the jets were just like winshield washer nozzles, they sprayed right onto the ic.

The early WRX's used a top mounted intercooler to make it easier to package.
Quite simply its cheaper than running pipe to the front, making space to put it, and then getting more boost from the turbo to over come the pressure loss.
It used air flowing in the top of the bonnet and out the underside of the car, but would suffer from terriable heat soak if stopped or traveling slowly.

The WRX STi, however was a little differnt, it used a front mounted intercooler, that also had a water sprayer. It ran higher boost levels, had a differnt bumber and also cost a bit more.

So, you guys are saying the lancer's front mount is better than the STI's top mount? Is that true for the newer STI's(04-06) too?

when the car is in motion, it really doesn't matter where the intercooler is mounted as long as its getting a large quanity of ambient air. That will counteract any heat soaking. Its when you're stuck in stop and go traffic, for example, and then suddenly hit full boost, the heat soak will have not been removed yet, and that could cause hotter intake charge temps than prefered.

The power difference between where the intercooler is mounted is mute. Its how you mount it that matters, how the tube's are routed, size and style of intercooler, not where it is. Pressure drop due to tube length is miniscule if you set it up properly.

Turbo timers were a great idea when turbo's were air cooled. With modern water-cooled center sections, its really not all that necessary. I have never bothered babying my turbo's, and they have never had a coking issue.

The early WRX's used a top mounted intercooler to make it easier to package.

The WRX STi, however was a little differnt, it used a front mounted intercooler, that also had a water sprayer. It ran higher boost levels, had a differnt bumber and also cost a bit more.


I can't say anything about how cars are over in NZ, but i have 2 friends w/ 2004 STi's and they're both topmount...no big deal, but another benefit the top mount is that there is very little charge piping which makes for less pressure drop and more instant throttle response. You use a smaller frame turbo and a foot of piping and you have low end power and torque all day long, but you do have to worry about heat soak. That's why, like Moppie said, they have water sprayers for the IC in order to cool it down in order to avoid power loss and detonation.

damn....i need an alarm to ring everytime someone post a new thread here cos i'm always last to answer