no stupid questions jsut stupid people

ok just a few questions that i think i need cleared up before i start to mod out my vr4.
1. Wastegate. What is it and what does it do?

2. Blow off valves. Do i need 1 or 2? And where do i put it(them)?

3. Boost controler. Is it worth having without upgraded internals or fuel pump and injectors?

4. What is the main differance that makes more hp in the later gens vs the 1st gen?

5. If i buy a different downpipe do i need one with an 02 eliminator for a 92 vr4?

6. What can i do to beef up the tranny?(manual)

ok just a few questions that i think i need cleared up before i start to mod out my vr4.
1. Wastegate. What is it and what does it do?

2. Blow off valves. Do i need 1 or 2? And where do i put it(them)?

3. Boost controler. Is it worth having without upgraded internals or fuel pump and injectors?

4. What is the main differance that makes more hp in the later gens vs the 1st gen?

5. If i buy a different downpipe do i need one with an 02 eliminator for a 92 vr4?

6. What can i do to beef up the tranny?(manual)

1. http://www.rtec.ch/turbo_basics.html

2. There is one on the car and, no, you don't need to replace it if you are only going with BPU.

3. Yes - its worth it. The stock boost does not get to what the fuel system can handle. You can take it to about 14psi and a boost controler is what you need (along with a guage as the stock one is innacurate).

4. Mainly the boost is upped 3psi, which can be overcome by the boost controller.

5. I don't understand the question. Getting the downpipe will improve airflow which will increase performance, but I am confused by what you mean by an o2 eliminator.

6. Nothing.

ok just a few questions that i think i need cleared up before i start to mod out my vr4.
1. Wastegate. What is it and what does it do?

2. Blow off valves. Do i need 1 or 2? And where do i put it(them)?

3. Boost controler. Is it worth having without upgraded internals or fuel pump and injectors?

4. What is the main differance that makes more hp in the later gens vs the 1st gen?

5. If i buy a different downpipe do i need one with an 02 eliminator for a 92 vr4?

6. What can i do to beef up the tranny?(manual)

i'll reply to this one too :biggrin:

1. A wastegate functions by opening and closing allowing how much boost will be run by the turbocharger. It stays closed until the controlled boost level is achieved, then opens up.

2. You wouldnt need 2 unless you are trying to accomplish some sort of show, 1 bov is plenty, although i do recommend replacing the stock blow off valve (bypass valve) because it tends to leak. A common cheap replacement is the 1st generation dsm (eclipse/talon/laser) blow off valves

3. Get yourself a proboost mbc for now, its $18, and you can turn up the boost to roughly 14.5 psi max without any problems, any higher and you will hit fuel cut. The internals can take a beating, nobody has ever maxed out the 3/S internals yet, and is predicted that they can hold up to 1,000 hp (4 bolt main) and the 2 bolt main has proven to hold over 600 hp. If you do get an mbc, you will need an aftermarket boost gauge, but you can get a VDO for around 30 bucks from www.importpoweronline.com

4. The only difference in power between the 1st gens and 2nd gens are the boost levels. You can easily take care of that by removing the nipple restrictor in your boost solenoid, and then you will be making 2nd gen boost levels.


5. Aftermarket downpipes will bolt up without problems if they are made for the 3/S.

6. To beef it up, really nothing, only thing you can do is get a more powerful clutch and a lightweigh flywheel. My buddy with a BPU RT/TT has trouble holding his power at 14.5 psi and therefore needs a better clutch.

thats exactly what happen to me, my clutch got destroyed from the power my car is making, it was just twisting and barely catching.


if you are getting or have a 1st gen vr4 you will only be able to turn boost up to 12psi without fuel cut, i'll explain.

2nd gens are at 11 psi and can turn up the boost by 3 making 14psi without any trouble. 1st gens go up by 3 from 9psi to 12 without any problem. but at that point you need the super afc to push it above 12 in 1st gens.

if i'm not mistaking yogs i think i remember you saying that with a fuel controller you can go up to 17psi? i know a guy who runs 17psi with a fuel controller and thats just for racing, he's actually at 8psi for dailey driving :dunno: so in question do you guys think that we can use 17psi without damage as long as we have a fuel controller, this guys vr4 is still fine stock turbo's and all, what do you think?

thats exactly what happen to me, my clutch got destroyed from the power my car is making, it was just twisting and barely catching.


if you are getting or have a 1st gen vr4 you will only be able to turn boost up to 12psi without fuel cut, i'll explain.

2nd gens are at 11 psi and can turn up the boost by 3 making 14psi without any trouble. 1st gens go up by 3 from 9psi to 12 without any problem. but at that point you need the super afc to push it above 12 in 1st gens.

if i'm not mistaking yogs i think i remember you saying that with a fuel controller you can go up to 17psi? i know a guy who runs 17psi with a fuel controller and thats just for racing, he's actually at 8psi for dailey driving :dunno: so in question do you guys think that we can use 17psi without damage as long as we have a fuel controller, this guys vr4 is still fine stock turbo's and all, what do you think?

i'd say that its possible to run 17 psi just for the fact that the stock turbos will begin to fall back if running 17 psi at around 4000-4500 rpms and will hold about 10 or 11 to redline

but electronic boost controllers can alternate that to hold for a longer period of time. for the simple fact when i put mine at 14psi and punch it if fuel cut didn't come to play it would hold for a nice while. i think gain hs something to do with it.

did miss read what you said? or am i right(well i know i'm right just looking to see if you know were im coming from)

but electronic boost controllers can alternate that to hold for a longer period of time. for the simple fact when i put mine at 14psi and punch it if fuel cut didn't come to play it would hold for a nice while. i think gain hs something to do with it.

did miss read what you said? or am i right(well i know i'm right just looking to see if you know were im coming from)


well, what i'm saying is that you could probably get enough fuel in for the stockers to run that much boost if you tune it properly, although on an upgraded turbo you would not be able to supply fuel to hold 17 psi to redline. The reason why you could do it on stock turbos is simply because the boost level falls back because they dont flow enough air into the engine to maintain its 17 psi to redline.

You can run 1st gens higher than 12 psi without a air/fuel controller. You only need to add a fuel controller if you upgrade the fuel system(injectors/pump). You can use a controller to achive better milage or get tweak a few more HP from it.

If you want to push any 3S past 14 psi you should invent in a datalogger that will let you check for knock. Knock will tell you what the limit for boost is.

14.5 seems to be the limit for pump gas. Some have gone to 17. But to me its not worth the risk of blowing the engine for that few extra HP.

My theroy, every dollar that you spend on doing the job right and not running on the ragged edge, is a dollar you won't have to spend on replacing a blown enging.

well then i guess every 3kgtvr4 is diff because i cannot go over 12psi without fuelcut and i'm not the only one. once i go over that and punching it it will get up in rpms and then stutter and jerk basically telling you to bring it down cause this is too much for me right now. i even checked on the internet for suggestions and they all say get the superacf II and you can remove your early fuelcut. so, i guess there all different.

Are you sure your not getting spark blow out?

What do you have your plugs gapped to?
How old are your plugs?

Yeah that sounds like spark blowout to me to, get copper plugs and gap them to .28-.32, then see if you can boost higher. Fuel cut is really violent and the car dies, spark blowout is like hestation/stutter jerk repetative cycle feeling.

If its spark blowout, he does not need coppers, just gap the stockers to .28

The advantage of copper it that you can run a wider gap. Of course you have to change them more offen.

i changed my plugs about 2 months before i got my boost controller, mitsu gave me a tune up. this only happens when i go above 12psi. thing is this other guy says the same thing happen to him and the superafc removed the problem. thats why i thought it was fuel cut.

and also i know what your talking about, with the spark plugs, befor i got mine done thats exactly what was happening which is why i got the tune up. then it was gone. but this feeling is diff, its similar to boost cut. hell it might be boost cut but when i look for a boost cut remover for our cars they always point to saying the superafc will remove your problem

If mitsu instaled the plugs their gapped at .38-.35

Pull them and gap them down to .28-.29 and then you'll be able to turn up the boost.

i HOPE your right seriously cause this would be a lot cheaper on me lol, instead of buying this $350 fuel controller. if your right i'll give you some points :)

I trust the info I get from the forum I admin ;)

And from running 14 on my car before the turbos and other mods ;) ;)

i HOPE your right seriously cause this would be a lot cheaper on me lol, instead of buying this $350 fuel controller. if your right i'll give you some points :)Have you checked this out yet?

not yet, i'm a sluffer, and its irritating for me to get to the back plugs so i was just gonna spend a bill to have somone do it for me. but i'll get too it soon.

oh yeah and it only occurs at full throttle cause i put it up to 13psi and it will psuh smoothly but if i punch it all the way at around 5 grand it will hesitate.

again thanks for the help