Max boost with stock head gasket

[savagebreed]

I have a 87 with a upgrated turbo te44, intercooler 23 row slic, 3"downpipe, 009 injectors, fuel reg all that good stuff. I was wondering the max boost I can run without blowing a head gasket? How much boost can this motor handle the internal is stock? has 130 on the clock.

 

[Ryan87GN]

If you have the fuel, a lot. Mine has seen about 38psi. When I put a grainger valve (mbc) on my car, nobody else really ran them at the time. I wasn't sure how to set it right. I turned the valve all the way in (up), and shortened the wg rod as far as I could

My combo is about the same as yours, but bluetops. I ran 25 to 30 psi on 28* timing regularly. 110 to 117 octane most of the time. Make sure there is ZERO knock. At that level sh*t goes boom real quick.

 

[86george]

I have a 87 with a upgrated turbo te44, intercooler 23 row slic, 3"downpipe, 009 injectors, fuel reg all that good stuff. I was wondering the max boost I can run without blowing a head gasket? How much boost can this motor handle the internal is stock? has 130 on the clock.

Anything above 0 is risky.With good gas 20-22 lbs is fairly safe.Anything above that,the head gaskets can let go anytime.The bottom end can take some abuse but then again the crank can fall out while driveing down the street.Tune it safe on the fuel and don't get crazy with the boost and enjoy the car.

 

[Razor]

I have a 87 with a upgrated turbo te44, intercooler 23 row slic, 3"downpipe, 009 injectors, fuel reg all that good stuff. I was wondering the max boost I can run without blowing a head gasket? How much boost can this motor handle the internal is stock? has 130 on the clock.

Using what gasoline? 93 premium 15-17 PSI. 110+ octane 25+ PSI.

The stock gaskets are tough to blow.. as long as you dont detonate it. :redface:

 

[turbodave231]

Answering your question is difficult because there are so many variables involved.......and You are really asking the wrong question. You should ask: How much detonation can the stock HG take?

Answer: Very little. It takes only a small amount of detonation during High cylinder pressures to push out a stock HG.

Stock unopened engines have been pushed up to and beyond 30 psi boost with no head gasket failures. How, you ask? only by avoiding detonation. To avoid detonation, you need to get a handle on tuning these engines.

To explain: Detonation is the premature ignition of the air/fuel mixture before the actual ignition event occurs. That means the peak cylinder pressure happens before the piston reaches TDC on the compression stroke. All the force of combustion is trying to push the piston back down the bore before the piston even gets to the top. Something has to give..........If you're lucky its only a HG......not so lucky and you'll drive over the crankshaft.

Alot of things help avoid detonation: Cooler inlet charges, higher octane fuel, richer Air/Fuel mixtures. Under power forced induction engines need richer mixtures than Normally Aspriated engines. 11.0-11.75 to 1 ratios seem to be common for Turbo engines. Some guys prefer even richer mixtures. Alcohol injection as an example, richens the mixture, drops the inlet charge temp and depending on the type of alcohol used has at least 100 octane (if used by itself). You can see that improving these variables all help avoid detonation. That's why alcohol injection is very popular for these engines.

 

[bison]

I ran 28psi long ago with c16 or maximal and a mild ported head combo with an old PT54. Car went 124mph at 3600+.Circa 1999. You cant have any detonation. If you dont they wont blow for a long time. More often than not guys have head gasket failure from not enough octane. Id shoot for a 10.8:1 a/f in 3rd on a wideband. 11.0-11.3 is ok if you have c16

 

[savagebreed]

I have razors alky kit forgot to say that in the first post. I was just about to order a chip from tt and eric wanted know my max boost I wanted to run. I figure I wanted to be safe 21-22. would it be that big of a difference from 21-22 to 23-24 max? I have ran 20lbs at the track with the alky and have no issues I run 13's flat with stock tires. I wanted to step it up for more power but as I said I want to be safe. Thanks for the help

 

[turbodave231]

If you want to be safe, start monitoring the engine and turn up the boost slowly. Don't turn up the boost if you have no idea what is happening!!

I'd monitor one or all of these parameters: Knock Retard, A/F ratio, EGT

EGT isn't as necessary as the first two, but can be a good indicator of A/F ratio if you don't have a wideband. And in my case, I don't monitor Knock Retard because I run solid roller lifters (which create some false knock). So I use C-16 fuel and concentrate on A/F.

You will notice that I didn't include the stock narrow band O2 readings?!! Reason: Simply not accurate enough for good tuning decisions

If you blindly follow someone else's " build recipe", sooner or later you will end up with a broken engine. Understanding what is happening inside the combustion chamber will allow you to make the changes needed to avoid dangerously lean operation.

 

[Razor]

I have razors alky kit forgot to say that in the first post. I was just about to order a chip from tt and eric wanted know my max boost I wanted to run. I figure I wanted to be safe 21-22. would it be that big of a difference from 21-22 to 23-24 max? I have ran 20lbs at the track with the alky and have no issues I run 13's flat with stock tires. I wanted to step it up for more power but as I said I want to be safe. Thanks for the help

I see said the blind man

The boost you seek is no problemo as long as it doesnt pickup spark knock. And as you increase your boost you want to see an increase in MPH. If it doesnt increase MPH, back it down.

Street tires can get your tranny into trouble as your prone to peddling it when it blows the tires. This also causes the knock sensor to flare up as well.. I have never had luck with knock sensors and spinning tires..

Keep fluids clean, keep it out of knock, for a 12-13 second car the narrowband has worked for many. Just make sure its in the upper 700's/low 800's and work on it from there.

HTH

 

[salvageV6]

Get the chip made for 23/24 psi.

You can start around 20 with it and work your way up.

Learn the scanmaster, EGT, wideband O2, direct scan, powerlogger, and use what you can afford and can learn out of those devices.

A good fuel pressure gauge helps too.

Oh yeah knock sensors/meters and audible alert help too.

And you shouldn't have any issues getting to where many were about 10 years ago.

These days with better alky. chips out there it isn't that hard to do relatively safely.

 

[gczarny]

I see said the blind man

The boost you seek is no problemo as long as it doesnt pickup spark knock. And as you increase your boost you want to see an increase in MPH. If it doesnt increase MPH, back it down.

Street tires can get your tranny into trouble as your prone to peddling it when it blows the tires. This also causes the knock sensor to flare up as well.. I have never had luck with knock sensors and spinning tires..

Keep fluids clean, keep it out of knock, for a 12-13 second car the narrowband has worked for many. Just make sure its in the upper 700's/low 800's and work on it from there.

HTH

agree 100% here , our T Buicks need to be loaded all the time which means traction all the way , if you brake tires loose , trans sleeping ETC , load goes away and MAP sensor starts leaning out , before you know it.... it detonates ,this all happens very fast , also agree with " RAZOR " first replay that stock HG are hard to blow but I need to add to it ...only if it is stock motor ....iron to iron / stock heads .... once you put GN1 heads and bigger turbo :biggrin: ...detonation is a killer but it is a bigger killer when you making 600 RWHP then 300 RWHP hope this is clear , so play safe , 22-24 lbs boost with right tune and Razor alky is safe even with major motor build /big turbo it has to be however ....like everybody here said .....O deg. of detonation ,last thing ...13 sec. pass on 20 PSI with TE44 /009 is slow period ,so either you have no traction or realy bad tune , we need to figure out what it is before you crank up the boost

 

["Turbo-T"]

To echo some of what the others have said, I've always heard it's not how much boost, but if you have detonation or not.

 

[savagebreed]

When I launch I have 0 boost and traction is a huge issue tires break really bad. Car is also out of tune as I had the wrong chip. I just ordered the new chip and asked for 23-24 psi max. I will start at 20 and see how it goes. I'm buying some wheels from summit along with drag radials this week.

 

["Turbo-T"]

IStreet tires can get your tranny into trouble as your prone to peddling it when it blows the tires. This also causes the knock sensor to flare up as well.. I have never had luck with knock sensors and spinning tires..

How do street tires get your tranny in trouble....???

Just wondering......

 

[waddell87]

Poor choice of words edited by Lee_Burough

 

[waddell87]

How do street tires get your tranny in trouble....???

Just wondering......

WHY YOU WONDERING??? DONT YOU KNOW EVERYTHING????????

i got what RAZOR was saying quite easily, guess you live in your own world, obviously Razor doesnt have clue what he's saying, that's why you don't understand...RIGHT? hmm why don't you tell us what HE meant MR "oh so know so much" Pretty simple to the average joe I think! Please Enlighten us NEWBIE'S

 

["Turbo-T"]

This quote repeated multiple examples of poor choices in words not by 87Regal3.8SFI. Edited by Lee_Burough

Uuummm I was talking to Razor, not you. PS don't bother sending me anymore threatening PM's either.

 

[ttypewe4jim]

Uuummm I was talking to Razor, not you. PS don't bother sending me anymore threatening PM's either.

What is so hard to understand excessive wheel spin can make the knock sensor go off..... juding by half your post lately on the forums you know everything anyway tho

 

["Turbo-T"]

What is so hard to understand excessive wheel spin can make the knock sensor go off..... juding by half your post lately on the forums you know everything anyway tho

Jim,

I understand wheel hop can cause the knock sensor to send off a signal. IIt's happened to me before, many times. I wasn't sure exactly what Razor meant the way he worded it which is why I asked. Guess I should have not asked?

And I never claimed to know more than anyone else, if I did then why would I be here asking questions?

 

[ttypewe4jim]

Watch the LV8 when the tires break loose

87regal sry for the attack its been a long week.