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Discussion Starter #1
just changed my exhaust to 3 inch and divorced the internal wastegate from meeting up w/ the exhaust stream til further away...now the car went from 10 psi to 13...how much is too much???
 

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well depends on how much you care about gas mileage...
but if its not knocking and you arent outside the efficiency band of the turbo than its all good
 

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Hell yes it is.

Think about it, n/a pistons can usually handle about 8psi with 11:1 compression ratio before they blow the ring lands out. I'm supprised the kit is a 10psi kit in the first place. That seems pretty dangerous in itself.
 

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Discussion Starter #4
just went and drove it, i bailed out at 7000 rpm...the boost went up to 12 psi
i am spraying water/methanol....does anyone know if the efi standalone can see knock?
 

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It ain't free power... You will definitely reduce the engines safety margin as well as decrease the life of the engine at that boost level.

How long do you expect to get out of the engine before you need a rebuild?

I don't believe there is anyone with a Turbo in a Elise application that is running that much boost without a built engine.
 

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13 PSI big bang

The earlier writer is correct, the ring lands, the area between the rings will collapse and that will be the END!

5 to 8 PSI is a max and if you don't have a controller and waste gate it is probably spiking above the 13 PSI in third gear.

Good luck!:mad::(
 

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Unless you ask for it, I don't think DRS sets up the EFI to monitor knock. The 2ZZ is apparently quite noisy and that sound dynamic changes a good bit under boost, which makes the stock knock sensor somewhat unreliable...

Your best bet, regardless of knock sensor, is to pull your plugs and take a peek... Big surprise coming from me;) Check those plugs for little black specs on the porcelain. If you have a spare set of plugs laying around, take this as an opportunity to cut the threads off and look at your mixture.

Chances are that 12 psi is pushing the limits with stock compression and pump gas...

Best,

Phil
 

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What mixture of water/methanol are you using? 50/50? Which injection system? Is it progressive?
 

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00 MRS - 2ZZ NA
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You guys really need to visit that lowly Celica GTS website that happened to have had the 2zz since 1999...

http://www.newcelica.org/forums/showthread.php?t=243977

The purpose of this thread is to explain once and for all the relationship between power, strength of internal components and boost.


The Boost myth

I couldn’t even begin to count the number of times a week someone asks the question “How much boost can I run on a stock 1ZZ” or “How much Boost can I run on a stock 2ZZ” or “How much Boost can I run with these internal mods” without any more info on their setup.

So – newsflash – aside from how it impacts type of couplers and clamps used boost is completely irrelevant. Boost will be different at the same power level based on turbo efficiency, intercooler efficiency, tune, cams, intake and exhaust, etc. Anything you do to improve the VE (Volumetric Efficiency aka how easily the engine breathes) will allow you to make more power at a lower indicated boost level. Boost essentially is a function of the turbo or superchargers ability to cram more air into the intake manifold than the engine can effectively pass. This is why you tend to see a flat spot or dip in boost when lift engages on a 2ZZ – the larger lift and duration of the big cam lobes drastically increases the vehicles VE (ability to breathe). This reduces the “restriction” that the cylinder head poses allowing a higher volume of air to flow at lower pressure. Less efficient turbos will also heat the air more, which will result in higher pressure or boost, but a much less dense and hence less potent air charge. This is why bigger turbos tend to make much more power at lower boost levels.

OK – now that you understand that boost is irrelevant, what you need to know is that what matters are power and tune. The amount of power being made is what determines the point at which components will fail. This is dependant on a good solid tune. A really bad tune can cause internal component failure on any vehicle at very low power levels. Torque is really the factor that matters, but it isn’t talked about much so I’m going to talk in terms of HP instead.

This being said – on a perfect tune the following seem to be the limits of the stock components:

2ZZ
Pistons – ring lands seem to crack or fail at the 250 / 275 WHP mark
Rods – No reported failures from over-power
Block – no block failures due to power, but based on the lack of ring strength most people who want over 300 whp get sleeves and aftermarket pistons
Bearings – probably best to change these out at or above 300 WHP
Head bolts - Replace with studs if you have to take the head off for any other upgrades. They seem to be fine at most common power levels, but they should not be re-used.


1ZZ
Pistons – ring lands probably will fail at about the 250/275 WHP mark
Rods – have failed below 250 WHP mark
Block – No block failures due to power that I am aware of. Best to stick with close to stock bore size at higher power levels above 300 WHP
Bearings – probably best to change these out at or above 250 WHP
Head bolts - Replace with studs if you have to take the head off for any other upgrades. They seem to be fine at most common power levels, but they should not be re-used.


That I am aware of no-one has failed ANY of the aftermarket upgraded rods, pistons or bearings due to over-power.


Jesse's thoughts on Tuning and how much boost is safe on a stock Celica Motor:



While I didn't intend this post to be a "You need to tune your car" thread, Jesse is exactly right. There are a couple people on this board that are accomplished tuners, and there are a couple high level recreational tuners, and then there are a WHOLE lot of people with basically untuned time bombs
 

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I'm running the EFI with 12 PSI, upgraded to the GT28RS from the FF275's GT28R turbo. Has had a few thousand miles running this way and the car just feels so perfect. I don't know how long this engine will last but who cares, when it blows up, it'll give me an excuse to built the motor up and go to 16 or more PSI. :nanner:
 

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I'm running the EFI with 12 PSI, upgraded to the GT28RS from the FF275's GT28R turbo. Has had a few thousand miles running this way and the car just feels so perfect. I don't know how long this engine will last but who cares, when it blows up, it'll give me an excuse to built the motor up and go to 16 or more PSI. :nanner:
Did the FF kit involve changing the pistons?
 

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Hell yes it is.

Think about it, n/a pistons can usually handle about 8psi with 11:1 compression ratio before they blow the ring lands out. I'm supprised the kit is a 10psi kit in the first place. That seems pretty dangerous in itself.
+1
 

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I'm running the EFI with 12 PSI, upgraded to the GT28RS from the FF275's GT28R turbo. Has had a few thousand miles running this way and the car just feels so perfect. I don't know how long this engine will last but who cares, when it blows up, it'll give me an excuse to built the motor up and go to 16 or more PSI. :nanner:
I don't remember the exact numbers, but Ronin was starting to get some leakdown on one cylinder after running his stock compression engine hard for over a year at around 270whp. Of course that gave him a good excuse rebuild the engine and up the boost. For more info you can find info on the other Monkey related board.

Ring lands are known to catastrophically fail, but I would bet that this is more than likely due to detonation than sustained pressure.

So keep the boost and run higher octane fuel to avoid detonation and you'll likely be fine from blowing up... but you'll be likely still looking at a rebuild in the near to medium future regardless.

(p.s. I have a fully built engine with custom turbo setup, bigger GT2871R turbo going on next week and redoing my manifold. Looking at ~350whp at 20 psi - dyno in a few weeks.)
 

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00 MRS - 2ZZ NA
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I'm running the EFI with 12 PSI, upgraded to the GT28RS from the FF275's GT28R turbo. Has had a few thousand miles running this way and the car just feels so perfect. I don't know how long this engine will last but who cares, when it blows up, it'll give me an excuse to built the motor up and go to 16 or more PSI. :nanner:
Instead of going through all that trouble...how about you purchase Mahle 9:1 low compression drop in pistons from dustylax here for $500 shipped and run as much boost as you want up to 400 whp (as long as your block is within specs)...MWR ran past 400 whp on a completely stock block...and past 700+ whp without sleeves in their built block and Mahle drop in pistons...

The only reason I could ever warrant buying a built 2zz past 300'ish whp over a stock block is if I want to have a greater margin of safety for the bearings not breaking (which is the 2nd to go after the stock piston ring lands)...or 9,000+ rpm rev limit with a built head that will also improve VE.
 

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Well if he is tracking the car it would be a lot wiser to buy a built block vs. just dropping in pistons due to the severity of driving that is involved in track days.

My next step is methanol injection then built motor. Hopefully have it done by this time next year. We will see how the fall/winter goes for me.
 

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Mahle pistons are usually NOT drop in.
Mine were fortunate and dropped in... although my block only had 6k on the clock. Don't forget to upgrade the rod bearings and head studs... and while you're at it the oil pump... and if you're going to do all that you better do the clutch as it won't hold... then you might as well do the flywheel. If you're now running that much power you may want to think suspension and brakes too... the list grows.

Even if the Mahle pistons drop in, its not a completely trivial job. Going over 300hp takes more work than pistons and upping the boost. BTDT.

You might as well buy the built block that Aztec has for sale.

My advice for the OP is to turn the boost back down to 8psi (if you haven't retuned already you're likely outside of where your car was tuned for) and be happy or bite the bullet and do it right like many have already done or are doing right now (Mainelotus).
 

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Discussion Starter #20
thats a lot of input for one day! thanks
the ignition timing is at 9 degrees advance or so above 11 psi. with the water/methanol and the fact that i don't track the car other than an occasional drag race, i'm optomistic that the motor will be fine for a while....if it goes bang i'll put pistons & studs in the thing...i would rather stay with at least 10:1 compression pistons though, are they available in a production unit or only custom???
 
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