808 rev limit happening at 4500rpm?

[Jayme]

yeah ouch........ speedway cars running stock 808 tunes on ecotecs are a dead engine waiting to happen......

not enough fuel, too much timing... ecotecs run about 15 deg timing at WOT, 808's on APNX run about 24-29 at WOT. right up in ping territory.
go to an engine builder and tell them, hey my speedway rules say I MUST run my engine lean with too much timing and watch them shake their heads... from memory, some of the ecotec engine builders for speedway run with filed sensor teeth in their balancers to knock 10 deg timing off them lol.

when will the meatheads that make the rules realise that ecotecs are a DIFFERENT engine to buicks and let them at least run the correct factory ecu and tune???

[vlad01]

the pistons are brittle as in ecotec. I seen one guy on fb blaming The1's tune for going through 4 engines in a row, all smashed pistons. one even died in few min of driving.

I offered to help out and out of process of elimination of mods he'd done, soon as he said high flow walbro.

I told his to toss it and get a genuine stock pump, I was willing to bet the pump was shite china copy and starving the engine of fuel causing to detonate itself to bits.

I nailed that one right on the head. No more blowing up engines after that.

Amazing that they are that sensitive to knock damage. Not like the buick tough pistons lol.

[immortality]

LOL, yep, light weight pistons to reduce rotating mass, thin crowns cause they took a whole inch of the deck height compared to the old 3800 V6 but with the same stroke.

[Holden202T]

from memory of when I put the ecotec onto an 808 it was like jayme said, way too much timing, and it was rich as down low and lean at the top end, so its a recipe for disaster whichever way you look at it.

[vlad01]

LOL, yep, light weight pistons to reduce rotating mass, thin crowns cause they took a whole inch of the deck height compared to the old 3800 V6 but with the same stroke.

thats not the issue, problem is they are high silicon alloy which makes them brittle. This is so they have lower expansion rate, thus allowing for tighter tolerances, lower wearing alloy and thus less blow by and friction = better efficiency.

The old Buick ones are more malleable and even more interesting is the early ford e series pistons are so malleable I couldn't break them with a sledge hammer, they just kept mushing up like a block of lead.

[immortality]

Yes, that is very true about the high silicon content but does mass not effect the frequency at which an item resonates?

And I was under the impression that tighter tolerances should lead to a quieter engine, the quality of the rings and bedding in process would still dictate how much blow-by you get.

[vlad01]

Yes, that is very true about the high silicon content but does mass not effect the frequency at which an item resonates?

And I was under the impression that tighter tolerances should lead to a quieter engine, the quality of the rings and bedding in process would still dictate how much blow-by you get.

you're probably right about the blow by but a sloppy piston certainly wouldn't help it with less control over the rings in the lands.

higher silicon gives pistons anti scuff and wear properties.

[delcowizzid]

Currently have the same issue on a 304 turbo weak springs sounds just like limiter.can't even get past 5200 rpm in neutral lol.when on boost it hits boost and then instant limiter even lower in the rpm New springs on the way