i had my evo VIII for about a yr. now. Did some drag races got 14.5 sec keep in my i was very nervous and also it was my very first time. here's the question. I don't have a boost gauge and is it neccesary to get one. and will it help me on my 1/4 time. u see i know some what about what a boost gauge does. it tells me when my boost stops right. well i figure if i get that i would know when to shift. i really just shift @ 7000 rpm. what do u think ???

 

You wouldn't know when to shift by looking at a boost gauge. Since your car is stock, you'll notice it drop off on the top end anyways. A boost gauge is a necessity in a turbo car. It will not benefit you in any performance aspect, however. Do some searches, you'll probably find a more detailed/specific answer.

 

Your boost doesn't stop until you let off the gas. It won't help you "find" your 1/4 mile time, just provide you information as to what your engine is seeing from the turbo. You're 1/4 time is probably high due to poor launching...but that will come with practice. If you plan on installing a boost controller, then you absolutely need a gauge but until then its not needed.

 

You've really got to watch for other modifications such as an exhaust as this can cause a boost spike...Maybe not as critical as a boost controller, but vital nonetheless.

 

boost gauge is a must have.

 

how come evo 81?

 

a boost gauge is a must have because it allows you to keep watch on your boost levels. this is important for several reason.

1) certain mods (ie. exhaust, intercooler) allow better airflow which in turn raises your boost. When i put my turbo-back exhaust on I saw an increase in boost of about 1-1.5psi. You need to keep an eye on boost levels when modding to ensure a safe level of tune before driving WOT very much.

2) too much boost can melt a piston. You want to make sure you are running within safe limits of the engine. Too much boost can cause lean conditions, too little boost can cause rich conditions b/c there is not as much air being forced into the engine as there should be to balance the amount of fuel being dumped into the engine. Too rich is not as dangerous as too lean but both can cause problems.

3) It is a diagnostic tool used to assess the engine and turbo's efficiency. If you sense a loss of power, or something strange happens, alot of times it is a boost leak, or lower boost due to temperatures, etc. With a boost gauge, you can quickly troubleshoot a problem and most time solve it without much hassle.

4) When you get a boost controller, you are basically buying a volume knob for your turbo. You can turn it up and down as you please. How are you going to know how much to turn it up or down without a gauge showing you what the car is currently running.

A boost gauge should be the first mod anybody with a turbo car does. It can even be important with a stock car. I remember a few people who had completely stock evo's that weren't as fast as they should have been. When they hooked up a boost gauge, they were only seeing around 16 psi, when they should see 19.5psi stock. It's the same reason people put gauges for A/F ratios, EGT, etc. Like someone said above, do a search. Research about turbo cars in general as well as boost gauges and controllers. This may give you some insight as to why it is so important. It helps you keep you car from running poorly. Hope this helps

 

thanks en1gma19 .i would have just gave a couple of words,but you went all out.

 

You say a boost controller is like a volume knob for the turbo. Does that mean you could maybe turn off the turbo or make it barely functional, say to increase gas mileage?

 

you can only turn the turbo down as much as the wastegate will allow. With the boost controller set to the lowest setting it will allow, what happens is the turbo spools until the wastegate opens. The wastegate on the evo is set at 11-12psi. Therefore, 11-12psi would be the lowest boost you could turn it to.

See https://www.evolutionm.net/features/...machvcorner/30 for more info on boost controllers

 

If you ever start to mod it, buy one. Your boost will tail off at higher RPM's so if you short shift and stay in the higher boost and keep her spooling, you will get better times.
I don't think the computer will lean the a/f just because you restrict the intake pressure, I think it is more involved than that.
BMan

 

think so huh. do a little research and see what everyone has reported. I've been around long enough to know what i'm talking about. you'd be surprised what the stock ecu will do to try and keep things "safe"

and btw, shifting to early while trying to 'keep her spooling' doesn't necessarily net better times. there's info on that to. do a search.

 

This wasn't a dis on you.
I was commenting to 008 and you posted while I was typing.
I was only saying that the 1st mod should be a boost guage and that with my stock EVO, I find it to have better power (at least the rpm's rise quicker) from 4200 to 6400 rpm in every gear.
[edit] and that putting a mbc at real low boost will NOT increase gas milage [edit]
BMan

 

that's cool man. i wasn't dissin you either. i'm just saying that i've read many posts where people report richer or leaner a/f ratios due to the addition of a new mod. hell, putting on a turbo-back exhaust made my car run substantially richer.....i could smell it!!! that's all. you'd be surprised what the stock ecu will do when parameters are altered.