i did a search on this but came up with nothing. i was wondering if you have constant boost in fifth gear(ex. highway driving) , if you are putting a lot of stress on your motor. the reason i am asking is because i drive a lot of highway miles and always cruise at the speed of 75-80 mph(but never higher). and i was wondering if it would be safe for me to be boosting for long periods of time while on the highway. if not then i don't think turbo would be my route.

p.s. i only wanted something for good power but more importantly reliability so i have my heart set on a greddy turbo kit. i drive a 00 si

 

you wont boost when cruising, do not worry. freeway driving is fine. i have also wondered about this before. from what i read, its ok if its tuned. gotta watch out for the EGT.

i have boosted in 5th several times when i am too lazy to downshift.

 

The boost generated by driving on the freeway is fine. You probably won't hit your max boost unless you floor it, or have a tiny turbo. My tiny stock wrx turbo spools everytime I tap the gas at 80

A bigger turbo will prevent that problem though

 

it's not exactly good to do cuz even though it may not boost as much it will put a lot of thermal loading on the blades which will produces a lot of heat and i think it puts a lot of pressure on ur cylinder walls too <- not 100% on that one

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vteg &raquo;</TD></TR><TR><TD CLASS="quote">The boost generated by driving on the freeway is fine. You probably won't hit your max boost unless you floor it, or have a tiny turbo. My tiny stock wrx turbo spools everytime I tap the gas at 80

A bigger turbo will prevent that problem though </TD></TR></TABLE>


yeah i worry a lot about freeway driving. my setup is basically stock gsr with apexi IHI p13 bb turbo (which is only lightly larger than the wrx turbo)

spool will come fast....

 

I used to boost in 5th gear and it was fine, if your running the afc hack it advances the timing under partial throttle, so try not to boost in 5th gear at partial throttle.

 

Shouldn't be too bad. Just keep an eye on temps....Your intercooler works best on the highway because it has a constant flow of cooler air.

 

you can boost on and off in fifth. just not longer any way 10-15 seconds

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by System-7 &raquo;</TD></TR><TR><TD CLASS="quote">you can boost on and off in fifth. just not longer any way 10-15 seconds</TD></TR></TABLE>

Yea that's what I was going to say. Just as long as you're not like topping out in 5th gear from low rpm with a lot of load, you'll be fine. I always boosted in 5th gear on the highway. All of the n/a suckers have to downshift

 

I love 5th gear boost. MPH climbs so fast. 80..90.100..120..ok enough of that. You'll be fine

 

see someone said just don't boost in fith for like more than fifteen seconds. thing is, is that on my si to go 80 mph my rpm is at about 4500. so i go eighty miles per hour constantly for about forty five minutes. this is my question on whether my motor will withstand boost for that long of a period. if it can't then i may just go all motor type-r.

 

Are you listening to what people are saying? You do NOT boost all the time. It is totally up to you when to go into and out of boost. It's completely controllable.

 

sorry but i am not a turbo pro so some of that stuff is going over my head. but how do you control your boost? how do i dictate it when i am at 4500 rpm for like forty five minutes?

 

If you plant the gas... ****'s gonna boost captain.

If you have the cruise on/partial throttle then your turbo isn't really "boosting" persay.

So to answer your question... you'll be fine cruising @ 80 MPH w/ a B16-T.

 

Do you know anyone w/ a turbo car and a boost gauge? If you ride/drive one, it'll all make sense to you. Basically, when you want to GO, boost comes in

 

you dictate boost with trottle. just because your engine spinning faster, doesn't mean its automatically going into boost. its not so much rpm related.. its rather throttle related.. yes, at higher rpm you'll have more response.. but until you really hit the throttle, you will not go into boost..

btw.. driving at hwy speeds and boosting in/out generates the most heat. if you want temps to stay down, take it easy on hwy if driving for long periods of time.

 

i cruise all day at 80mph and i'm at like 15 - 20 inches of VACUUM.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vtec.dc2 &raquo;</TD></TR><TR><TD CLASS="quote">you dictate boost with trottle</TD></TR></TABLE>

boost is dictated with LOAD not throttle. bottom line, ur not going to be boosting while cruising on the highway. my SOHC greddy kit doesnt even, only when i pass people.

mike

 

Well, when I cruise on autobahn, I usually drive ~110mph for almost half hour... when need to slow down for traffic, i just nail it in 5th gear.. sometimes even for longer period for nice speeds (a little longer than half minute floored).
On my tiny D14 with small turbo at that speed (~110mph) I'm usually at ~2psi boost.
So far no problem.... hope it won't blow :&gt;

 

Okay. Let's dispell a common misconception.

Revolutions per minute have little to do with boost.

Boost is a function of CFM. CFM is dictated by throttle position. Meaning that boost is more dependant on how heavy your foot is on the pedal than anything else. RPM are dependant on throttle position, but it does not take nearly as much throttle to maintain engine revolutions as it does to accelerate.

Constant speed driving = insignificant boost.

 

when going down the the higway you will go into vacuum when cruising even if your rpms are at 4500. if you jab the throttle the turbo will spool super fast since the rpms are already up. that answer is DONT WORRY ABOUT IT. you will not have a problem driving to work. when you boost your car and you are driving down the road you will figure out what i am saying. you wont be in boost.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Freemantle &raquo;</TD></TR><TR><TD CLASS="quote">Okay. Let's dispell a common misconception.

Revolutions per minute have little to do with boost.

Boost is a function of CFM. CFM is dictated by throttle position. Meaning that boost is more dependant on how heavy your foot is on the pedal than anything else. RPM are dependant on throttle position, but it does not take nearly as much throttle to maintain engine revolutions as it does to accelerate.

Constant speed driving = insignificant boost.</TD></TR></TABLE>

CFM is NOT dictated by throttle position for the simple fact, when you go up a hill and it creates load the turbo may spool without pressing the gas(depending on incine)..therefore LOAD is the dictator. Load can be increased by gear, throttle position AND acceleration (amongs several things).

mike