Boost Precaution
10-23-2003, 12:14 PM
#1
Senior Member
Thread Starter
Join Date: Aug 2003
Posts: 145
Hi,
I am getting a street ported engine soon... i will be using the stock turbos for a while... ppl tell me that with a ported motor i will have to port the wastegate too... is that necessary??
can i do it my self.. Oh i have a boost controller too... will that help... or will i need to port the wastegate..
Pics would be appreciated....
Also how much boost can the stock clutch take??
thanks
I am getting a street ported engine soon... i will be using the stock turbos for a while... ppl tell me that with a ported motor i will have to port the wastegate too... is that necessary??
can i do it my self.. Oh i have a boost controller too... will that help... or will i need to port the wastegate..
Pics would be appreciated....
Also how much boost can the stock clutch take??
thanks
10-24-2003, 09:03 AM
#3
Member
Join Date: Aug 2003
Location: Greenville NC
Posts: 51
What ppl?
Don't even think about it!
All the wastegate is doing is routing exhaust gas straight through the exhaust system instead of through the turbo. It is wasting the boost that isn't needed.
I don't even think this is possible without doing some major work that could really mess up your turbo system. The only gain you may see from this is that your exhaust system would be less restrictive when wasting exhaust gas. Hardly worth the effort and/or risk.
If you don't feel comfortable with this answer, ask the guys that are porting your motor.
If you have the stock down pipe with the first stage cat in it, you would be better off replacing this with a free-flowing system. I feel certain that this is more restrictive than the wastegate on the turbo system.
The clutch is limited by total HP at the flywheel; not boost. I am pretty darn sure that your clutch is going to be fine for a while. I am also pretty sure that the manual specs out the stock clutch. Check it and see if your expected HP is going to exceed the capabilities of the stock clutch.
Don't even think about it!
All the wastegate is doing is routing exhaust gas straight through the exhaust system instead of through the turbo. It is wasting the boost that isn't needed.
I don't even think this is possible without doing some major work that could really mess up your turbo system. The only gain you may see from this is that your exhaust system would be less restrictive when wasting exhaust gas. Hardly worth the effort and/or risk.
If you don't feel comfortable with this answer, ask the guys that are porting your motor.
If you have the stock down pipe with the first stage cat in it, you would be better off replacing this with a free-flowing system. I feel certain that this is more restrictive than the wastegate on the turbo system.
The clutch is limited by total HP at the flywheel; not boost. I am pretty darn sure that your clutch is going to be fine for a while. I am also pretty sure that the manual specs out the stock clutch. Check it and see if your expected HP is going to exceed the capabilities of the stock clutch.
10-25-2003, 12:02 AM
#7
Senior Member
Join Date: Dec 2002
Location: San Diego, CA
Posts: 205
Well you don't port your wastegate to make exhaust flow more efficient. You port your wastegate because you've increased the airflow to the turbo so much that the stock size wastegate can't bypass air around the turbo fast enough to keep boost under control. This is called boost creep. As rpms rise your boost pressure will continue to rise even higher than you want it to because the wastegate can't keep up. It will usually happen on a stock motor if you remove the all the cats and get a high flow muffler. A ported motor would probably make it even worse.
10-25-2003, 01:54 AM
#8
Senior Member
Thread Starter
Join Date: Aug 2003
Posts: 145
Well you don't port your wastegate to make exhaust flow more efficient. You port your wastegate because you've increased the airflow to the turbo so much that the stock size wastegate can't bypass air around the turbo fast enough to keep boost under control. This is called boost creep. As rpms rise your boost pressure will continue to rise even higher than you want it to because the wastegate can't keep up. It will usually happen on a stock motor if you remove the all the cats and get a high flow muffler. A ported motor would probably make it even worse.
Exactly my point.... I don't want my new engine to get screwed because of the boost creeping... I have a Knightsports Dual Downpipe and a somewhat free flowing main cat and an Apex-i n1 installed....
The Engine i got direct from Japan and i don't want to screw it up.... It costed me alot...
Also how much hp increase should i expect from a street port with the stock turbos....
and any tip on how to run in the engine
Thanks
10-25-2003, 02:56 PM
#9
Member
Join Date: Feb 2003
Posts: 37
What do you mean by "somewhat free-flowing main cat"? What kind of intake are you running? What type of ECU? Boost creep is usually more of a problem if your exhaust system is fully open with no cats (as in MP); hi-flow cats don't suffer from it as much, although every car is different, so it's been known to happen.
Using the stock wastegate, a boost controller will basically only let you raise boost, not lower it (based on the flow capabilities of the stock wastegate compared to your intake/exhaust mods). Especially with a streetported motor, which is obviously opening up your intake side.
Too many variables to say "you'll get this much more hp with a street port using the stock turbos". Boost level, intake/exhaust mods, ECU, etc.
Everyone has their own ideas on break-in, but my pattern is to keep it below 4500 rpm for the first 500 miles with no full throttle/full boost applications, but some occasional short moderate-throttle bursts through the gears. Also, vary your rpm as much as possible; don't take it out on the highway and cruise it at a steady rpm for an hour to get 500 miles under your belt. The biggest part of break-in is multiple heat cycles-- letting the engine cool off, then run up to temperature. After 500 miles, you can do some occasional full throttle/full boost runs, but don't make a habit of it, and until you've done 750-1000 miles, don't do a "dyno-pull" full-throttle run all the way up to redline in 4th gear.
Using the stock wastegate, a boost controller will basically only let you raise boost, not lower it (based on the flow capabilities of the stock wastegate compared to your intake/exhaust mods). Especially with a streetported motor, which is obviously opening up your intake side.
Too many variables to say "you'll get this much more hp with a street port using the stock turbos". Boost level, intake/exhaust mods, ECU, etc.
Everyone has their own ideas on break-in, but my pattern is to keep it below 4500 rpm for the first 500 miles with no full throttle/full boost applications, but some occasional short moderate-throttle bursts through the gears. Also, vary your rpm as much as possible; don't take it out on the highway and cruise it at a steady rpm for an hour to get 500 miles under your belt. The biggest part of break-in is multiple heat cycles-- letting the engine cool off, then run up to temperature. After 500 miles, you can do some occasional full throttle/full boost runs, but don't make a habit of it, and until you've done 750-1000 miles, don't do a "dyno-pull" full-throttle run all the way up to redline in 4th gear.
