Around 300hp power goals?

[Alec]

change your fuel filter like i said on sf. when i put my motor in my new shell it was running lean by the looks of the whitish plugs(didn't have a wb) and just wasn't pulling like it did up top in my old shell. changed the fuel filter and problem was solved. i even cut it open for fun. and holly shit is all i can say. there was so much grit in there. not to say yours is going to be as bad but its cheap and easy to do. just dont twist the line.

what you really need to do is check the compression. that will tell you what shape you engine is in. if the #'s are low i would hold off on the mods.

http://www.cygnusx1.net/Supra/TechTips/compression_test.aspx

lol, my Supra runs rich. Most Supras run rich, and I have my BOV vented to the atmosphere which makes it run even richer, lol. So I don't think I need to worry about it running lean. But I will change the fuel filter and Lambda sensor when I have a chance.

 

[SUPERIUM]

I doubt you will hit 300 @ 11psi but crank it to 15+ you probably will depending on how healthy your motor/turbo and bolt ons are.
My friend just dyno'd his stock rebuilt setup and made 312rwhp and 417lbs tq. @ 15-18psi on the stock turbo. His mods include 3" Brullen exhaust/hi-flow cat, Raptor Racing ddp, lex afm, bosch bpv, 550s, 255 pump, griffin rad., stock i/c and piping.
He probably would of made a bit more power but the stock wastegate reached its limits.

 

[Alec]

I doubt you will hit 300 @ 11psi but crank it to 15+ you probably will depending on how healthy your motor/turbo and bolt ons are.
My friend just dyno'd his stock rebuilt setup and made 312rwhp and 417lbs tq. @ 15-18psi on the stock turbo. His mods include 3" Brullen exhaust/hi-flow cat, Raptor Racing ddp, lex afm, bosch bpv, 550s, 255 pump, griffin rad., stock i/c and piping.
He probably would of made a bit more power but the stock wastegate reached its limits.

I'm going to stay just under fuel cut, around 11 psi. I don't care how much power it makes, I'll be happy with it.

 

[HommerSimpson]

I give you 2 weeks at 11 psi before bhg if that long.. on 140k mile hg.. no ofence.. just have not heard much of them lasting 140k at stock psi..

 

[Alec]

I give you 2 weeks at 11 psi before bhg if that long.. on 140k mile hg.. no ofence.. just have not heard much of them lasting 140k at stock psi..

There's people who have 250k miles. Don't jinx me, think positive!

 

[hvyman]

those peopel with that amount of miles without a bhg are like .2% of produced mk3s. valve covers wont help detonation and venting a bov only makes you run rich when let off the gas.

 

[berniek]

The stock head gasket has rolled back metal liners in each of the cylinder bore openings. All other factors being equal, construction of that type would be fine. However, it ignores one very important fact: The engine is long (unlike a V6), the head is aluminum, and the block is iron. Over slightly more than a 100C temperature cycle, the head grows slightly less than .035" in length with respect to the block. THAT is the cause of the problem with stock head gaskets, because the temperature cycling "rolls" the rolled-back metal liners each time the engine is started from cold and each time the engine cools down. Eventually the rolled-back liners fatigue. THAT is the reason that the end cylinder sealing fails first, because the end cylinder gasket roll-backs suffer the most during differential longitudinal growth and shrinkage from temperature cycling.

Metal HGs are made in layers to SLIDE with respect to each other. My Cometic has four layers, if I'm not mistaken. The present car is a '91 with a built up JDM GTE. The former car was a 90, fully stock, which blew the HG despite retorquing. The gasket blew at 165K miles.

Be safe. Get a metal HG. Lap the top of the block. Check it with a precision straightedge and feeler gauges to get it flat.

BernieK
'91T, non-targa, refreshed JDM, Walbro, Lex, 550cc ND injectors, 57 trim turbo at 17 PSI (at 3000 pipe), '98 wheels and engine mounts (strong!), Lipp, modified stock FPR, Treadstone IC, hardpipes, Cometic, ARP, Random Tech 3" single cat downpipe, HKS LET-T16 exhaust, Exedy organic clutch (street use), Cr-Mo light flywheel, Raptor BOV (recirculated), deflashed valve bowls, exhaust helicoils, tower strut.

Ignore that guy. People have made over 500rwhp with stock head gaskets and stock bolts. It's not that bad. Follow my advice, keep it out of detonation and it will last.

 

[FranklinWaters]

I give you 2 weeks at 11 psi before bhg if that long.. on 140k mile hg.. no ofence.. just have not heard much of them lasting 140k at stock psi..

those peopel with that amount of miles without a bhg are like .2% of produced mk3s. valve covers wont help detonation and venting a bov only makes you run rich when let off the gas.

Mine had 163k and I thought it was a BHG. It ended up being loose head blots that gave me the symptoms of a BHG, but I just went ahead with a MHG. I was running 10psi at the time. Not saying this is the case for all supras but I might be in the .2% :biglaugh:.

 

[Alec]

Besides guys, the previous owner of my car has had 11 Supras and he said that this engine is as strong as all of his other ones. One of which he ran 16 psi daily, stock HG, stock bolts. He said that he would feel comfortable boosting it.

 

[RazoE]

well yeah, the HG is not weak, it's just torqued down improperly..

if you're running mild stuff, you could possibly get away with just a retorquing, but that all depends on the individual motor, previous owner, current owner, and lady luck...

the thing is, once you hit 300, you'll want more, which will then require a MHG anyway, so you might as well do it now, as the last thing you'd want is a BHG, followed by rod knock..

It's a rod knock life for us, it's a rod knock life for us...for you get the B-H-G, then you get the R-O-D..!

 

[Alec]

well yeah, the HG is not weak, it's just torqued down improperly..

if you're running mild stuff, you could possibly get away with just a retorquing, but that all depends on the individual motor, previous owner, current owner, and lady luck...

the thing is, once you hit 300, you'll want more, which will then require a MHG anyway, so you might as well do it now, as the last thing you'd want is a BHG, followed by rod knock..

It's a rod knock life for us, it's a rod knock life for us...for you get the B-H-G, then you get the R-O-D..!

I'm not gonna want more than 300hp because I wouldn't be able to afford to. lol

 

[7MsuprO]

Besides guys, the previous owner of my car has had 11 Supras and he said that this engine is as strong as all of his other ones. One of which he ran 16 psi daily, stock HG, stock bolts. He said that he would feel comfortable boosting it.

The previous owner also wanted to sell you his car and you bought the car and the things he told you. The fact that this motor is "as strong as the other ones," or "he said he would feel comfortable boosting it" doesn't mean much. I'm going to differ from others and say do whatever you want to do which seems to be to run the stock HG. If it blows, dont be surprised...

Oh and also, did you re-torque the stock head bolts? Torque to yield bolts tend to stretch (like any bolt) but do not un-stretch (like normal bolts) if that makes sense. Because the head bolts are so old AND the head is aluminum which has a high expansion rate, the bolts maybe stretched far enough to not provide a sufficient clamping load. On top of this your head could also be slightly warped which is common. All these things will affect your head gaskets longevity. Not trying to be a downer but food for thought...

 

[Alec]

The previous owner also wanted to sell you his car and you bought the car and the things he told you. The fact that this motor is "as strong as the other ones," or "he said he would feel comfortable boosting it" doesn't mean much. I'm going to differ from others and say do whatever you want to do which seems to be to run the stock HG. If it blows, dont be surprised...

Oh and also, did you re-torque the stock head bolts? Torque to yield bolts tend to stretch (like any bolt) but do not un-stretch (like normal bolts) if that makes sense. Because the head bolts are so old AND the head is aluminum which has a high expansion rate, the bolts maybe stretched far enough to not provide a sufficient clamping load. On top of this your head could also be slightly warped which is common. All these things will affect your head gaskets longevity. Not trying to be a downer but food for thought...

Stock bolts are NOT torque to yield. And yes, they were re-torqued. The previous owner was not just "saying that" to sell me the car. I am good friends with him and he is an honest guy. Besides, he told me this after I purchased the car.

 

[tlo86]

jzs had the TTY iirc

 

[Alec]

jzs had the TTY iirc

That might be true. All I know is that the 7M stock bolts were NOT torque to yeild, they were the same design as the ARP's.

 

[7mgtorC]

Get a metal HG. I just blew my headgasket on an 80,000 mile 7m.. It leaves you traumatized! lol..

Stick to bpus and do not put up the boost at all if your not going with the metal HG. Intercooler and descent sized hardpipes as well as a DDP will make a big difference like Razoe said.

Just keep in mind that the Head gasket is a MUST. Either now or in the future if your modding your car. If i were you id get it done ASAP.

 

[Keros]

As far as I know, a stock ECU should not "lean out and detonate" because fuel cut will stop fuel long before the fuel pump or injectors are maxed out... assuming that the rest of the fuel system is in decent shape. If you add a lexAFM or different injectors, or both, the ECU will not work the same.

Basically what I'm saying is you cannot detonate a stock ECU with a stock fuel and ignition system in good condition. If it's been done, it's likely that something wasn't stock or wasn't in good condition.

As for any dicussions on bolts and the stock headgasket, you're playing the cards if you keep the stock headgasket and up the boost past stock. It might hold longer than you keep the car or it could blow tomorrow... there's no way to know. Doing things like headbolt/stud replacement, retorques, new rad, new coolant hoses, ect, will all help keep things intact. But nothing short of a rebuild will be 100%. And even that... well, can be screwed up.

I'm running an internally stock JDM 7M-GTE, stock headgasket, with ????km, ????prior condition, and an installation job that left much to be desired. I keep the boost as close to fuel cut as possible without going over and so far it has taken what I've thrown at it, including track days. I replaced all the trouble coolant hoses, cleaned up the rad, new intercooler system, 3" elbow back exhaust, K&N, new PCV system... and other nits and bits. It's probably a solid 280rwhp, more than enough to get into serious trouble pretty fast.

But after all that, I know that at any moment I might hit the gas and it'll bog because coolant just flooded a cylinder. I sleep soundly at night and keep a premium AMA membership up to date. I've done about all I can to keep the engine together without doing a rebuild. I have 550cc injectors and a LexAFM sitting in my bookshelf at home... I debate whether it's really worth it. Do I fuck with it for just a little more or do I thank my lucky stars it's lived as long as it has and leave well enough alone.

The age old question. A question I'll probably debate right up until my 2JZ is up on a hoist going in the chassis.

My advice to you, is if you want to drive the car, don't dink with it. If you're willing to rebuild it after you fuck it up, then go ahead and make more power. I'm not going to tell you your headgasket will take it, but I know that's what you want to hear. Just make a simple choice to accept the responsibility that YOU blew up the headgasket, not the car, the Gods, or Jerry Sienfeld. If you can accept that and can still sleep at night, go ahead. If not, then leave well enough alone and don't screw with something that works.

 

[Alec]

As far as I know, a stock ECU should not "lean out and detonate" because fuel cut will stop fuel long before the fuel pump or injectors are maxed out... assuming that the rest of the fuel system is in decent shape. If you add a lexAFM or different injectors, or both, the ECU will not work the same.

Basically what I'm saying is you cannot detonate a stock ECU with a stock fuel and ignition system in good condition. If it's been done, it's likely that something wasn't stock or wasn't in good condition.

As for any dicussions on bolts and the stock headgasket, you're playing the cards if you keep the stock headgasket and up the boost past stock. It might hold longer than you keep the car or it could blow tomorrow... there's no way to know. Doing things like headbolt/stud replacement, retorques, new rad, new coolant hoses, ect, will all help keep things intact. But nothing short of a rebuild will be 100%. And even that... well, can be screwed up.

I'm running an internally stock JDM 7M-GTE, stock headgasket, with ????km, ????prior condition, and an installation job that left much to be desired. I keep the boost as close to fuel cut as possible without going over and so far it has taken what I've thrown at it, including track days. I replaced all the trouble coolant hoses, cleaned up the rad, new intercooler system, 3" elbow back exhaust, K&N, new PCV system... and other nits and bits. It's probably a solid 280rwhp, more than enough to get into serious trouble pretty fast.

But after all that, I know that at any moment I might hit the gas and it'll bog because coolant just flooded a cylinder. I sleep soundly at night and keep a premium AMA membership up to date. I've done about all I can to keep the engine together without doing a rebuild. I have 550cc injectors and a LexAFM sitting in my bookshelf at home... I debate whether it's really worth it. Do I fuck with it for just a little more or do I thank my lucky stars it's lived as long as it has and leave well enough alone.

The age old question.

My advice to you, is if you want to drive the car, don't dink with it. If you're willing to rebuild it after you fuck it up, then go ahead and make more power. I'm not going to tell you your headgasket will take it, but I know that's what you want to hear. Just make a simple choice to accept the responsibility that YOU blew up the headgasket, not the car, the Gods, or Jerry Sienfeld. If you can accept that and deal with the aftermath, go ahead. If not, then leave well enough alone and don't screw with something that works.

Like I said earlier, I'm changing my valve cover gaskets this week along with my spark plugs and wires. The only mods I'm planning on doing are EBC at right below FC, full turbo-back exhaust, intercooler hard pipes, Fluidyne radiator, and possibly FMIC. I never really take my car above 5000 rpm. I generally shift at 3k-4k rpm.

 

[Boosted516]

I doubt you will hit 300 @ 11psi but crank it to 15+ you probably will depending on how healthy your motor/turbo and bolt ons are.
My friend just dyno'd his stock rebuilt setup and made 312rwhp and 417lbs tq. @ 15-18psi on the stock turbo. His mods include 3" Brullen exhaust/hi-flow cat, Raptor Racing ddp, lex afm, bosch bpv, 550s, 255 pump, griffin rad., stock i/c and piping.
He probably would of made a bit more power but the stock wastegate reached its limits.

dont stock cts die out after 14psi anyway?

 

[radiod]

Does anyone else feel like this thread is just circling around itself? 6 pages in short form:

Can you run 300hp with the stock hg/bolts? Yes
Do you NEED to change to a mhg/arp hardware? No
Should you change to a mhg/arp hardware? Probably

You can go and throw 300hp at the setup the way it is right now. All people are saying here is don't be suprised if the head gasket does blow on you because >50% end up blowing up on you. With chances like that, I would do the work before it bhg's and potentially causes more damage, and that's all that people are saying. Nobody here is telling you what to do, just giving their honest opinion because you asked for it.

Fact: My car's blown 3 stock head gaskets before a previous own put on the metal head gasket, and it's running around the same power that you are aiming for. I have receipts for machine work and rebuild parts, and it's not something you want to do if you don't have to.

It sucks getting answers you don't want to hear, but let's face it, we're all just being honest.

And to answer your question from a few pages back Boosted516, the car was dyno'd at 330rwhp.