Max Boost Questions
 

Ive been searching around and I have a few questions regarding the max boost that the stock fuel system can sustain.

Is the max. boost 10 or 12 psi? I read it was 12 if your running a intercooler and BOV. My car came w/ an intercooler and I was wondering to run 10 or 12 does it need to be a certain size because mine on the small side, being a foot squared and maybe 4" deep?

And I been searching around the net on this next ? and the answers vary widly, i guess because Engine setups are different and these were just generalizations. For 1 lb. of boost on the le28t (w/ intercooler and BOV) how much HP is gained? Or how much HP is gained from 10/12psi combined?

Thanks,
DGRIFFIN

yep... the exact answer to that question will always vary, as everyone has a diff setup. Here's some good info to read: Lots of good info on the web... http://www.mygen.com/users/dbruce/my...sor%20Maps.htm

The stock injectors start to lean out (on stock fuel pressure) at about 12-14psi. A RR FPR helps there. People refer to using an IC at higher boost for engine safety (cooler air helps prevent detonation) as well as performance (cooler air can increase power).

As for the size of IC to use... there's about 3 trillion intercooler calculator websites that help you pick the size you need.

And I remember reading somewhere that for each lb of boost, the basic estimate for hp increase on the L28 is 5-10hp.

Informative as always NismoPick. That really helps alot. Only 1 question what is a "RR FPR"?

Rising Rate Fuel Pressure Regulator. A good upgrade if you are going to keep the stock injectors & up the boost. There are different ratio ones, but 1:1 works best on the L28ET. 1:1 = For each lb of boost, the fuel pressure is increased 1lb. They go up from there... some extreme ones would be 12:1 (12psi increase for every lb of boost).

I know on my '88 ranger with the T-Bird turbo engine in it the stock boost was 9psi and I was able to run it at 14psi all day long..as soon as it hit 15psi it fell on it face and wouldn't go at all. Was that a fuel thing or timing thing...no intercooler on that truck either.

The T-bird engine had an intercooler from the factory... someone took it off? (I'm assuming it was an engine swap?)

You are correct sir, for some years, the year my engine came from was not intercooled. I actually bought the intercooler from a salvage yard but could not fit it under the hood anywhere or behind the grill.

If I raise the boost pressure & install a BOV what do I need to do to the ERV and the Wastegate? I've read you can either remove or modify the ERV.... which is better for engine life?

From this thread: https://www.zdriver.com/forums/showt...227#post164227

To increase boost, you need a boost controller. DO NOT BUY A MANUAL BOOST CONTROLLER. Spend the extra $$$ to buy an electronic one. To modify the EVR you need to drill out the rivet & install a washer or buy an aftermarket adjustable one. If your wastegate is in good shape, have an electronic boost controller, AND have an acurate boost gauge, you can cap it.

What's wrong with a manual boost controller? My homemade $10 boost controller works fine.

I made a $2 one that works too... but not very trust worthy. A pain to adjust too (pop the hood just to change the boost). I'd much rather pay for a more acurate, and easier way to control boost.

Mine has been rock solid. I just set it and forget it. If I need to change the setting, it takes maybe 20 sec. You're just lazy :unibrow: j/k

I do plan on upgrading to an electronic one eventually. I'm getting lazy too.

hehe... I am lazy, but I've found myself in several situations where I want to up the boost RIGHT NOW... I wouldn't have been able to pull over on the freeway, pop the hood, adjust it, and go. Instead, just pop my center console, dial it in, and wa-la!

I had alot of questions...man the search button really IS your friend....
So, 180hp est. stock at 7psi of boost...so if I am able to up the boost to 12psi I may be near 240hp??? Is this true??? As far as electronic boost controllers....what is cheap but good...I mean, what do you all recommend with a $200 cap? Back when I was messin with turbo stuff I was looking into the Profec B....am I outdated here?

240 might be a bit high for 12psi... but somewhere around there. Greddy, HKS, Apex-i, Turbo XS all make good EBCs. I bought my HKS one for about $150 on ebay. I haven't used the dial ones, but I think I'd still like mine better... push button selection w/ a screen to show me exact numbers.

http://memimage.cardomain.net/member...58_99_full.jpg

There is some drool coming out of my mouth......I think I am gonna try and get the ZXT home Friday. So much to look at and so much stuff to decide on....FMIC, BOV, RR FPR......I think it will be worth it....the ZX is a cool looking car.

I'm using a Profec B as my boost controller, no outdating there! It's very easy to use and install. Took me about 20 minutes to get it setup. 12 psi will probably get you anywhere from 210-240 whp depending on what you have done, and the quality of your gasoline. The 180hp is at the crank from the factory which is like 145-155 hp at the wheels. My Z bone stock hit 146 but that's with an autotragic transmission which sucks up more hp than a m/t would. Anyway, good luck and happy boosting!

I got the new AEM Tru Boost gauge-type controller. Basically, it's the size of, and shaped like a standard 2 1/16" round gauge. So I have it discretely installed in the middle slot of my center gauge cluster, where it's in easy reach. I'm keeping it around 9psi for the time being and hopefully I'll dyno it at MSA this weekend.

I was thinking, couldn't I install the manual boost controller somewhere in the car? Adjust the boost at anytime I want without pulling over to boost it? I haven't seen anyone talk about that, what the disadvantage of having a manual boost controller in the car?
Ben

Yes, that would work. You might have a slightly longer delay due to the vacuum tube length tho... which could cause boost spikes.

One other thing about some MBCs is that they are air density dependent. Meaning that your boost threshold will change depending what the altitude and air temp is. My friend has one and at night he has to change it a few clicks to maintain his boost, or else he ends up anywhere from 2-5 psi higher than he was in the daytime.