2006/04/10 12:13:24
mjbro10
as the compression ratio is just the ratio of the maximum volume formed in the cylinder to the minimum(clearance) volume, increasing it would have to produce more mechanical energy and a better thermal efficiency. Someone confirm?
2006/04/10 12:36:43
MR2Vaeth
mjbro: Yes, that is correct. However, it also reduces your ability to "add more boost" since the mixture in a higher compression engine is under a greater pressure than a mixture in a lower compression engine. A higher compression gives more torque (I believe), but will cause you to detonate at less boost (i.e. less air).
2006/04/10 13:06:25
KrAzE
quote:
Originally posted by MR2Vaeth
There you go, oils ain't oils. Use only the best full-synth oils for your engine if you care about it.



hmmm, VERY different from what Terry at Road and Track said on this issue. He said that the 3sgte doesn't like fully synthetic oil, and that people should only be using semi-synthetic oil, as the Synthetic stuff is too good for it...
2006/04/10 13:06:46
hotmr2
very interesting read. come on coming mate!
2006/04/10 15:46:11
MR2Vaeth
quote:
Originally posted by KrAzE

quote:
Originally posted by MR2Vaeth
There you go, oils ain't oils. Use only the best full-synth oils for your engine if you care about it.



hmmm, VERY different from what Terry at Road and Track said on this issue. He said that the 3sgte doesn't like fully synthetic oil, and that people should only be using semi-synthetic oil, as the Synthetic stuff is too good for it...



I'd have to say that the proof is in the pudding Kraze. Or in this case, the proof is in the lack of pudding in my opened engine.

Only possibility I can think of of why a semi-synth would be better than a full-synth is in circumstances/situations where the engine is already not in perfect shape (i.e. it has not been service regularly, and/or has been using mineral or semi-synth oil for a while) and putting in full-synth just highlights and brings out the problems already present. A semi-synth or non-synth in this case would hide the problems and makes the engine seem smoother.

That's my guess anyway.
2006/04/10 17:21:40
Renegade
Nice write up vaeth keep em coming. And your car is in good hands Tris knows what he is talking bout ;)

I have to agree with vaeth on the fully synthetic oil comment, when i first bought my car hmm 7 yrs ago I made the mistake of one day running normal pulp on a 38 degree day, anyway blown headgasket later which at the time I got the local toyota dealer to repair, and they were amazed at how clean and in good condition my motor was in, when they pulled it apart, they asked me what oil do I run as they have never come across a mr2 with 100,000ish km that was so clean. I was using mobil 1 full synthetic. Shortly after that they started using mobil 1 as there standard oil for services (so they must have been impressed)

And 3sgte motors are tough, i drove home with all 4 pistons totally destroyed, it was a little harder to start but apart from that it still went quite well all things considered
2006/04/10 21:40:57
2hardtop
[^]mmmmmmmm abused engine internals

Did you tell the workshop you do trackdays
as tuning for drags/street use (full throttle short periods)
puts in less heat stress than circuit(like 8 drags a lap,lap after lap for twenty minutes)
most customers just want a big number on the dyno, especially if another workshop says you should have at least xxx kw with that setup,
the customer thinks 'oh their crap tuners I should have xxx kw'

for circuit you need more margin for sustained heat and need to be generating less heat in the chamber(lean is mean)

a few workshops have tuned drift cars to the max dyno power
then blown them up when drifting for sustained periods.
2006/04/10 21:48:16
MR2Vaeth
Yeah I told the workshop I was going to be using it for the track, as I mentioned that many many times when I was telling him about the power band I wanted. Area under the curve >>> peak power any day anywhere in my books.

Besides, the track day that I blew my engine on was a track day run and organized by that same workshop. [B)]

And yeah, can't wait to get my MR2 back. The MX6 makes a good daily...big boot, sits four...but damn, and I hope I don't hurt anyone by saying this, FWD really really suxs. I mean, it's light and all that, and low, and it actually holds a tight turn pretty damn nice (credit where credit's due) but it just can't compare to an MR2.
2006/04/10 21:52:38
2hardtop
[}:)][}:)][}:)][}:)][}:)][}:)][}:)][}:)]
a plague on them then
[}:)][}:)][}:)][}:)][}:)][}:)][}:)][}:)]
2006/04/10 22:03:43
MR2Vaeth
Hehehe, thanks mate. I'm wishing them a plague of locust, frogs, and pox too.
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