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Discussion Starter · #1 ·
Now that I have the donor motor stripped down, would there be any problem in installing the 550's now ??? Would they still perform at low impulse on stock signals ??? Not planning on the Lexus AFM upgrade for a while yet but dont want to have to get back to the fuel rail later.
Like the metal head gasket and arp bolts, is this something that should be done JUST IN CASE ???
I need FACTS here, not opinions.
Thanks guys
DJ
 

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I'm assuming you mean slapping in some 550's with the stock fuel management? Effectively, you'll be dumping about 25% more fuel into the cylinder. The car may run, but it will be pig rich (ie run shitty). The O2 will compensate slightly, but not enough. Not to mention, at WOT and cold engine operation the O2 is not used. Plus, when cold, it will run rich to begin with, plus that 25%, it may not run at all. Plus you run the risk of frying some cats. I'd hold off in that case. The injectors arent that hard to change later. Remove the TB and with some wiggling around you can replace them without too much hassle.

Christian
 

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You want the facts? Here are the facts: Do not use 550cc injectors in 5m/6m unless they're for a 7m with a Lexus AFM and AFPR. A stock HG and head bolts would be fine for boost up to 12 psi (although there are others who boost higher). If you're planning on boosting much higher with upgraded turbo and fuel system then I'd recommend MHG with ARP head bolts/studs (you'll have to make sure that your head and deck of block are prepped properly for MHG).
 

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Ya, I meant 12 psi for 7mgte. Thanks for clearing that up as I don't want to be blamed for getting someone thinking "hey, I can boost 12 psi on my stock 5m with turbo!" :p
 

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:rockon:

Also, if you are thinking about running enought boost to take advantage of 550cc injectors you should be looking at forged pistons on a 5m (and possibly forged connecting rods). I am running 11psi on non-forged pistons (although they are not OEM). I could go a little higher if I had 315cc injectors (versus my 295's) but I dont think I would push it above 12 (maybe 12.5-13 for one dyno run).

Also with 550's on a 5m or 6m I dont think a piggyback fuel computer would do the job. I think you'd probably want to go stand alone.

Just food for thought.

What engine are you working on anyhow? Hopefully it is a 7m and I'll just shut my cake hole.

:lol:

EDIT: The fact that you mentioned the Lexus AFM mod tells me you are most likley working on a 7M. My cake hole is shut.

:chair:
 

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well, i honestly think you can run 14-16psi on a 5m with stock hg as long as you have the fuel to tune it properly. it is the detonation that kills the hg. there are people on sf. running 1.2bar and more on stock hg's. they have the same cast pistons and the same material for the hg. just tq it to 75lbs and it must be tuned correctly. tuning is the big factor in this. you could run 295's with a safc and then run 1-2 more injectors controlled by an aic(aditional injector controller) and mount the injectors in the pipe on top of the motor and tune above 10psi with the aic. not hard to do at all. most aic's go between $300-500 on ebay. some can be had new for less then $500. as for the 550's, dont put them in till you have the lex afm to go with it. all you are going to do is have a crappy running motor, really bad gas mileage, and lots of carbon buildup on the pistons, valves, combustion chambers and in the exhaust, as well as black soot on the back of your car. also you might fry that ~$180 o2 sensor.
william
 

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CRF_Rider said:
.... I could go a little higher if I had 315cc injectors (versus my 295's) ....
Just an Off-topic FYI.. 295's and 315's flow the same amount of fuel. The 315's were tested and are run at a higher Fuel Pressure (42 PSi as opposed to 36 IIRC), and hence the higher flow of fuel they show. If ya run them at the same FP as the 295's, you'll get the same amount of fuel from them. You can use the higher pressure FPR from a Mk III, but you need to have an adaptor block built. Jamie B has plans for the block if your interested.

Oh..and William is right. The Stock HG on a 5M-GTE, tuned right with fuel, will hold every bit as much boost as a stock HG on a 7M. They come off the same presses, are designed the same, and made from the same material. When properly torqued, in a properly tuned motor, they should behave exactly as a 7M would... I've seen Mk III's running 16 PSI with nothing but fuel mods and a stock motor (well, he did retorque the HG down to 78 FT/LB's) and he's had it that way for ~70K miles or so.
 

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Discussion Starter · #9 ·
Thanks a lot guys !!
I guess its either shit or get off the pot. Hhhhhmmmmm........not expecting completion until end of April anyways so.......
We'll see :lol:
Thanks again everyone.
DJ
 

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Oh..and William is right. The Stock HG on a 5M-GTE, tuned right with fuel, will hold every bit as much boost as a stock HG on a 7M. They come off the same presses, are designed the same, and made from the same material.
are you sure about this, bob? i kept hearing stuff about the redesigned stock head gasket for the 7mgte, different part # than for the 7mge. it had metal irngs around water jackets and less space between the rings around the cylinder bore or something.


shiva
 

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it is the same material. those rings around water jackets arent needed. toyota wont admit that the tq for the head was too low cause then that is a recall and they will have a buttload of cash to dish out. 5m and 7m hg's are interchangeable. btw, how many 5m's have you seen with a bhg? not as many as a 7m, turbo or n/a. just tq the head to 75lb's and tune it right and your fine.
william
 

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I would like to know who has boosted a 5m with stock pistons and stock HG (even with ARP studs) to 16psi.

Sorry, but I dont buy it. While I agree that detonation is the single most important factor in melted pistons or a BHG I just dont think the 5M was designed for that much pressure.

So please point me to the person or persons who have done this. I'd like to hear it from them.

Please dont take this personal guys. If someone steps up and said "I did this on my 5M and drove it daily (not just one dyno run)" then I will conceed the subject.

:wedrunk:
 

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DJ,you definately need a fuel computer at minimum for the 550's.S-AFC works well :wink: The Lexus AFM is pretty much a no brainer,more air,quite a bit bigger.

Mark,I think the 5/6m pistons will take the same abuse as the stock 7mgte stuff.They are both cast,not forged.Anything above 16psi without timing control is pushing it on either.Thats next on the list of things to play with.
 

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CRF_Rider said:
I would like to know who has boosted a 5m with stock pistons and stock HG (even with ARP studs) to 16psi.

Sorry, but I dont buy it. While I agree that detonation is the single most important factor in melted pistons or a BHG I just dont think the 5M was designed for that much pressure.

So please point me to the person or persons who have done this. I'd like to hear it from them.

Please dont take this personal guys. If someone steps up and said "I did this on my 5M and drove it daily (not just one dyno run)" then I will conceed the subject.

:wedrunk:

well, like i said above, you must have the fuel and tuning. most people would go with a 7mgte swap before spending the money for the necessary parts to tune a 5mgte to 16psi. if someone wants to donate the money for the project ill do it.
william
 

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scarletlizard:

If you go with 550s and stock AFM besure to take the adjustment screw all the way out. This will help lean the mix some and raise the fuel cut. Also drill out the J-tube return line hole. This will also lower the fuel pressure some and lean the mixture even more.
 

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Discussion Starter · #16 ·
Thanks for the input Wade. Something to consider for sure.
To everyone else:
This is a 7MGTE build.
Honestly, I dont have time to be experimental, nor do I have enough knowledge to push the envelope in Frankenstein bolt ons. I am relying on feedback for what should be best.
Another 2 decades of typical Toyota trouble free driving obtained from an "enhanced" transplant would be my ultimate goal.
Just hope THEY continue to sell gasoline for the next forseeable future.
Pisses me off that after all this I could be faced with a _______ transplant :mad:
Kinda long winded, sorry...
DJ
 

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Well, my 5m w/ stock pistons (9.2) blew at around 14psi (due to faulty evc4). It blew the headgasket on every single cylinder. 2 of the cylinders had three, yes THREE, spots on each cylinder blown out. the other 4 either had one or two spots blown out. Needless to say the car didn't start :p . Most of it was probly due to detonation, as all I had was an RRFPR. But that's my experience, just wanted to throw it out.

Christian

would like to know who has boosted a 5m with stock pistons and stock HG (even with ARP studs) to 16psi.

Sorry, but I dont buy it. While I agree that detonation is the single most important factor in melted pistons or a BHG I just dont think the 5M was designed for that much pressure.

So please point me to the person or persons who have done this. I'd like to hear it from them.

Please dont take this personal guys. If someone steps up and said "I did this on my 5M and drove it daily (not just one dyno run)" then I will conceed the subject.
 
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