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Re: 4-cylinder turbo performance

Posted: Wed Apr 30, 2014 12:44 am
by jamal555
I went for NGK 9 because i have idle problems in the summer when the car is hot, very hot.
I mean, not problems, but its not as smooth as with these i had 7 and 8, 8 are ok all year round, but in hard driving with stock ignition 9 give me smoothest engine running both on and off throttle in the 40c outside temperature.

Jim do u drive you car in winter? at -10c or similar, isnt 15w oil little thick for this engine?

Re: 4-cylinder turbo performance

Posted: Wed Apr 30, 2014 2:36 am
by Jim K
Yes I drive it all year round but -10*C?? In Athens we very rarely see less than -1*. The norm in winter is ~8-12*. Summer.... 42* is unfortunately frequent these last years. World climate changes....
Jim K.

Re: 4-cylinder turbo performance

Posted: Wed Apr 30, 2014 3:11 am
by bteoh
Ahhh....... Athens has quite similiar weather to Perth, Western Australia.
I normally use NGK B6ES or B7ES :)

Re: 4-cylinder turbo performance

Posted: Wed Apr 30, 2014 10:03 am
by jamal555
Thx Jim,

Mats u got brutal winters there, 15w not thick for u? i know 10w is default. or u dont drive turbo in the winter :)

Re: 4-cylinder turbo performance

Posted: Fri May 02, 2014 1:46 pm
by Mats
I never worry about the first number really, all modern oils are good enough.
Don't drive my hobby cars in the winter, no. But when I did drive my 75 T in the winter I used the same oil/plugs as in th summer.

Re: 4-cylinder turbo performance

Posted: Tue Sep 02, 2014 12:55 pm
by Jim K
The 1.8T I built for a friend showed 346hp (314whp) and 440Nm (318ftlbs) at ~4500. I drove it and I don't like it as it doesn't have much under 3500. I had asked them to buy the GTX2860, but Garrett here didn't have it and gave them the GTX2863 instead... Bad move. 350hp at 1.8bar (26.5psi) is not bad but I still don't like it. The intercooler is very small and they didn't get any more power with more boost. I asked them to take it up to ~2.2bar(32.4psi) but no luck. The owner is happy with the result so I'm happily out of the loop.
That's why I'm getting the GTX2860 for mine -maybe next week? Its a bolt-on replacement for my GT2871 even using the same water/oil pipes. I certainly expect better low speed performance and the possibility to exceed 2bar (29psi) provided the MSD6530 advance map can cope -that will be the result of very many uphill runs with the help of Knocklink and ...the human ear!
Jim K.

Re: 4-cylinder turbo performance

Posted: Sat Sep 27, 2014 7:18 am
by buzzed
Interesting thread, looking forward to seeing the end results.

Suggestions and queries:

1. Agree with others, air filter needs to go, I have seen this style of airfilter sucked into the compressor housing. I am surprised you only lost 2-3Hp through it, but as Hp increases the loss will also increase of course. Perhaps you can route the pipe to near the headlight? That would get it away from warm air also.
2. Are you able to use E85 fuel? You will enjoy less knock (but worse fuel consumption), and so will be able to wind in some more boost for given timing.
3. I do not expect a large change for the 2860, I think you will still be less than impressed with the lag, just a reality of higher mass turbo rotating assemblies. Of course I fully support your quest for yet more and more Hp :-).
4. Interesting conversation on squish before, my take on it is even in a turbo engine a smaller effective chamber is more desirable (less surface area for heat ot dissipate through). My understadning is that to achieve true squish (ie a volume where the flame can not effectively travel, the final gap must be less than 0.5mm, otherwise, the flame will traverse the gap).
5. what are peoples thoughts about very large turbines and larger overlap cams, in the quest for higher peak power (Jim, I know this goes against your quest for a good torque spread for streetability)? That is, seeking the possitve pressure ratio across the head? You should install a pressure gauge pre and post turbine. This will be very informative.
6. does this engine have piston oil squirters built into the block standard? I understadn they do?
Really enjoying this thread. I hope I can chime in with some dyno results of my own in the near future. I am running a 2L 8 valve engine....I am sure someone will take pleasure in telling me I am about to split a liner!

A pick of mine.

Re: 4-cylinder turbo performance

Posted: Sun Sep 28, 2014 6:36 pm
by Jim K
Here is the graph with wheel figures. Again, I don't like the non-existence of low range. I hope to improve a lot (in my car) with the GTX2860. There are no oil jets in these engines. Its not a question of lag, but of late spooling we have here. Reading the GTX2863 vs 2860 specs will show why.
Image
Jim K.

Re: 4-cylinder turbo performance

Posted: Mon Sep 29, 2014 4:26 am
by Greg Gordon
Jim, those are great numbers. Although the low end seems weak, it's important to remember this is all relative. Even at 3000rpm it has more power than just about any NA 2.0 has at peak power, and more than most NA 3.0 V6s have at that RPM.

Re: 4-cylinder turbo performance

Posted: Mon Sep 29, 2014 7:13 am
by Jim K
Wheel figures:
At 3k: ~60hp, 150Nm (109ftlbs), 0.15bar (2psi) boost
at 4k: ~185hp, 330Nm (239ftlbs), 1.05bar (15.2psi) boost
at 5k: ~295hp, 420Nm (304ftlbs), 1.8bar (26psi) boost
at 6k: ~310hp, 375Nm (271ftlbs), 1.75bar (25psi) boost
I would prefer a much better lower end... We'll see how mine pans out. Like I said, max power for me doesn't mean much out of the racetrack; it's just an ego trip. And then, there's always the question of driver ability -being able to handle power. Naturally enough, most people disagree with this!
Jim K.

Re: 4-cylinder turbo performance

Posted: Mon Sep 29, 2014 9:17 am
by Greg Gordon
OH, I was looking at the wrong scale. I thought you had around 150hp at 300rpm. Yeah, with only 60hp there, you need more.

Re: 4-cylinder turbo performance

Posted: Mon Sep 29, 2014 8:46 pm
by MD
Hey Greaser,

Why don't you stop scratching your butt looking for nuggets and fit a twin charge.
A supercharger for the bottom and a hair drier for the top. Best of both worlds.

If Shakespeare was alive today, he would snuffle you for top drama queen role I am certain. :mrgreen:

Re: 4-cylinder turbo performance

Posted: Tue Sep 30, 2014 4:00 am
by Jim K
Wise words from the 'Weirdo of Oz' or toilet bowl poetry? I think you have a blow-off valve issue! Try olive oil+valve grinding paste :lol:
Jim K.

Re: 4-cylinder turbo performance

Posted: Tue Sep 30, 2014 9:53 pm
by Maurizio

Re: 4-cylinder turbo performance

Posted: Wed Oct 01, 2014 6:13 am
by Jim K
The purpose of this 1.8T project is to come up with the best cost/performance solution without changing the original basics and the daily driver character of the car. The project is ~80% done, the only things remaining are the new snail, high-Z injectors and possibly a better intercooler radiator -remember the stock IC has been converted for water cooling. Thanks to std pistons/rods durability, no special forged components are needed even for serious trackday use. Stay tuned for end of story and dyno results with the GT2871 and GTX2860 snails.
Jim K.