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Max boost


GreekPower
04-13-2004, 04:37 PM
I was wondering wats the max boost setting the stock turbos on a vr-4 can handle is it 14.5?if its more like 15 or something is it smart to run at that setting for daily driving?and for a turbo upgrade whats the type of turbo i should get if i am going to get all new internals like i mean wats the max psi the turbos should be at like 35 psi?

Igovert500
04-14-2004, 02:36 PM
First off, 14.5...and that is with an aftermarket boost gauge, the stock one is highly inaccurate. If you overboost, everything may seem fine....until your engine blows. Over 14.5 your stock fuel system can't keep up, you will run lean = knock = your screwed and on the side of the road kicking yourself. Also at around 15psi, the stock plastic y-pipe has a tendency to blow off, you will hear a thunk against the bottom of your hood and you will lose power and coast to the side of your road. So basically...boost oto 14.5 with a boost controller and aftermarket boost gauge....higher with fuel pump, larger injectors, new y-pipe, and air/fuel controller. IF you overboost without hte right supporting mods you just killed your car. Many run 14.5 when they race, and then turn it down to 12 for everyday driving.

As far as turbo upgrades...there are about 20 different kinds of upgrades that can be done to our car. So you would have to be more specific as to waht your goals are, if you want a race car or a fast daily driver...if you want it to be most effective in a straight line or autocross style race with turns...you really have to be more specific. I suggest you do some reading and get to know these cars better before going crazy modding them.
Check out www.stealth316.com and www.3si.org, and read backpages of previous posts here on this forum. There is enough there to keep you busy for months and you will learn ALOT, and can make decisions for yourself. 99% of questions posted on this forum could be answered if people simply took the time to read.

GreekPower
04-14-2004, 03:05 PM
ok so if i do get like a downpipe,boost controller,boost gauge,intake,bov,720cc injectors,skyline fuel pump,different y pipe and a/f controller what would the boost be able of getting from the stock turbos before they blow? im using this for daily driving but on the weekend its for drag racing.so im wondering will the stock turbos go past 15psi and not blow up or do i need to get bigger turbos?

Igovert500
04-14-2004, 08:10 PM
Well first off 720s with stock turbos is overkill and you will be dumping gas and running rich. Unless you are getting huge turbos there is no need to go that big injector size.
Also, with forged pistons, propane injection, and other mods to handle more boost you could turn it up to 20, but you have to realize that this isn't constant boost pressure. At 15psi, the stock turbos can only hold 15psi to around 5000rpms. If the boost was at 20, they would only be able to hold it to 4000rpms. With stock turbos running 15psi, and the mods you listed up there you could be running high 12s. If you tweak the boost with a racing gas or propane you could run even faster. So it really depends what you mean by a drag racer on the weekends. If you are going to be serious about drag racing...do it right and get bigger turbos.
Go to stealth316.com, click on library, then on upgrade guides and on turbos...like I said before, do some reading

GreekPower
04-15-2004, 08:45 PM
o ight thanks alot igovert u should get like ur own site to answer ?'s ur really good at this

Igovert500
04-16-2004, 01:30 PM
Nah, just too much freetime...in between classes I get stuck on campus, cuz gas costs too much. I just love my car and did alot of reading on the various sites so I could learn as much as possible.

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