Ok the final results..
But first: How uncanny that today is the 28September. EXACTLY 1 year since the day I stripped the car down for the rebuild!!! That's spooky.
You've all over-estimated the final peak power figure from the T25, but not by too far really.
It made 131.4kw at the wheels on the "17psi boost setting". That's about exactly spot on triple the factory power output of a k11 micra.
We've found the limits of the turbocharger, it holds 17psi for a while, but then tapers back down to about 15.5psi at higher revs. So it actually made the 131.4kw only on about 15.5psi. He revved it only to about 7400rpm to make that power, the graph still showed an upward climb in power at this final stage, but he left it at that due to his "mechanical sympathy" as he described it haha. He said there's only a couple of kw more at slightly higher revs, and he has it limited to around 7600rpm now just for extra safety and I'm happy with that.
The injectors are now at full duty cycle at the higher RPM simply because my regulator is delivering a low fixed pressure. A solution for that would be to install some kind of riding rate or adjustable regulator to give it a higher base pressure, and then re-tune the entire fuel map to dish out less fuel and there would be more for the same duration of injector open'age. But they are fine on max duty cycle right now, its not running lean or anything, but its just something Jake noted at the very high RPM while tuning. There is much less time available to hold the injectors open at high RPM, so raising the rail pressure is one solution to get more fuel out during that same open time..
The turbo is pretty much maxxed out, Jake commented that the other thing limiting peak power is my current intercooler. It has a very long core which equates to a greater pressure drop, but that combined with the anorexic end tanks equates to a reasonable restriction. The engine can handle oodles more, but its the turbo running out of puff and a restrictive intercooler limiting the peak power.
Jake said if this turbo was boosted at this level continuously for long periods day after day it would have a short life. You can hear it working a lot harder now compared to when it was running 13psi the other day and still making 123kw. So after an additional 4psi, its only equated to about 8kw. That's another good indicator that the turbo is running out of puff along.
In its present state, the car now lights up both wheels easily in 2nd gear when boost comes on. It wasn't doing that the other day. So now I have to back off just to get the power down. In 3rd gear is is close at times to breaking traction aswell depending on the road surface. Jake hit a loose bit on his test drive and 3rd gear darted around a bit. He said that he doesn't think he would like to see much more power put through this chassis. Its very lively now and even on the lower 13psi setting very nice to drive without the traction issues and extra torque steer in 3rd gear. He said I might even want to back the boost down to the 13 or 15psi setting to get rid of the traction problems and it might equate to a faster car if the traction becomes annoying in 2nd gear etc. So I'll see how it goes.
Jake said ideally for longevity and ideal fitment, a ball bearing turbocharger unit with a slightly larger compressor would be ideal. However the cost of that combined with a better flowing intercooler and the tuning etc would be probably $2000-2500 in total and it might actually equate to a car that's not as "FUN" to drive. He said a ball bearing unit might make another 10-20kw PEAK power, but it might flow that well that it HAMMERS onto boost very quickly and just lights up the wheels, making the extra benefit effectively useless anyway and you've just blown two or three grand. That combined with the thoughts that there's a fair bit of power going through that chassis now makes you wonder. Its all about how it drives on the road, and not some peak power figure just to win a dyno shootout day.
So I have a lot of fun driving to do now, and over time I will think about what I want to get out of it or if I'm content. I may well decide to go for a phase 2 upgrade which would mean upgrading the intercooler and the turbocharger simultanouesly. It would make more peak power but also probably come on boost a fraction earlier. The key thing Jake said was that a ball bearing unit would make the same peak power on lower boost levels. That just for its longevity benefits is a desirable advantage for me. But the car right now is ultra-drivable as a super-fun daily driver, already beats a whole packet of "fast" cars (285 clubsport, R33 GTS skyline etc) so I'm loving it. There is every chance that just that extra bit of flow causing boost to RUSH on faster will make it actually a worse car to drive, it also could bring the risk of having a laggy car which would suck. I don't care if my car made 170kw@wheels, if its laggy and not as fun on the street, I'm not interested in that. After all, when is enough power enough?? Jake was very big on this theme, he said if you're happy with it, don't waste the money on the other items because its likely it will make a higher peak figure, but may well be worse to drive as a street car - its completely the same attitude that I have.. If you can put your foot down in 2nd gear and have both of your 195 tyres light up through an LSD and you have to back off, that's pretty reasonable.. I think next tyre upgrade I will go for some decent semi-slicks and see what improvements I can get.. But until then, I'm content and happy and just enjoying it now...
Here's a video of the dyno run [7.8 Mb]
Some early tuning results.
He gave it a run at 13psi and revved it out to 7500rpm, it developed 123.1kw@wheels. I'm very happy with that considering that was with the slight boost leak as above and with the heavy GTi-R brakes installed.
He said to drive it around a bit more, then the car goes back on Thursday. He'll fix the leak and then tune it a bit further up to 16-17psi. He thinks that will be about the max from the T25, it may not make much more power. I would probably expect it to put out 130kw@wheels or somewhere around that ballpark figure on Friday, all depends on how the turbo goes.
I have the car back now and have been going on a couple of dodgy stealth missions. It is considerably faster than it was before even right now with this small boost leak and not final tuning. (a) the tyres - I didn't have the Konigs for very long before, traction with those and the LSD is brilliant, it doesn't break traction in 2nd gear at all when it comes on boost!! I think I can hear it just starting to, but its very intermittent and it never spins or anything, the car bloody launches off ahead like a slingshot. (b) Jun flyweel. (c) better flowing exhaust. (d) more boost. Its easy to spin both Konigs in first gear, but 2nd just grips 100% and off you go. 3rd is crazy aswell, but I haven't gone any faster than 100kmh.
I took mighty for a quick spin and we gave it a squirt in 2nd gear and into 3rd, pushed us both back pretty hard and was lots of fun hehe.
It's more power than a factory 200sx puts out at the wheels :)
I'm interested to see what the old T25 does on Friday at slightly higher boost levels. See how it goes and that will get me started thinking about turbos..
Ducked over to Jake's this afternoon and was pleasantly surprised to see the car almost completely back together. Definately not long now.
More dodgy findings:
Again: so glad for this thorough rebuild.
So give it another few days and all the remaining parts should have arrived and be installed.
Here's some photos of the new engine after being freshly dropped into place. We quickly sat the turbo, exhaust manifold and dump pipe in place just to see how it looked and how much clearance it had against the new radiator. We found that it hits the radiator a touch and so the radiator has to go off to be slightly modified on its left hand edge.
As the new engine will be running high boost levels and making a fair amount of power, it was anticipated that it would probably be generating considerably more heat. The existing radiator was definately not up to the task as it had been modified by removing about 3 cores so that it allowed the old dump pipe and intercooler piping to fit. That was a very dangerous move because the old radiator was just a normal factory micra one approx 16mm thick, so the removal of those cores meant approximately a 10% reduction in cooling ability. This was not good news for a turbo engine developing a multiple of the factory power output.
The beauty of this new radiator is that it is effectively equivalent to almost 2 of those factory radiators. Its 35mm thick in total (whoa), but if you look closely, its actually two separate cores inside the single end tanks.
Jake's performance got some local Canberra radiator guru onto the task and he designed it for my particular application. It looks very nice in the flesh and now I will not be paranoid about whether the car may overheat or not.
The radiator's driver's side edge had to be slightly modified to clear the dump pipe because the exhaust place designed the exhaust manifold slightly too far to the right (good one you idiots!). But there's not much in it, and only a small amount of the actual heat element stuff had to be removed and the outer frame brought into form a slight indented section. No cores were actually removed. Because the radiator is such overkill anyway it will have no effect on its performance in the micra.
Here's some photos during the engine rebuild when the old engine was pulled out just before fitting the new power plant.
Discoveries made have been:
The block was honed and machined. This engine was a low km import engine that I sourced from Campbelltown wreckers near Sydney. The whole thing was disassembled and cleaned throughout. The engine was in perfect condition with virtually no wear. You can see in the 2nd and 3rd photos where some grinding was needed on each bore so that the enormous conrod clamps and ARP bolts didn't foul the bored. They collided before this grinding and the engine couldn't rotate! So this is a pretty serious custom rebuild haha. Its just excess metal on the bottom of the bores and doesn't do anything for strength, if anything the engine is a few grams lighter.
These photos show the engine shortly after assembly with everything in place except for the sump and cam cover.
Originally I had a ported UK-spec micra head. When Jake commenced the engine rebuild though, it was decided that we were better off starting completely fresh and porting the japanese factory head just so we were completely aware of all the tolerances that changed and exactly what had been done to it. It turned out that they ported the japanese head slightly more than what the UK one had been done anyhow.
This is a major step in the prevention of blown head gaskets. It makes a blown head gasket virtually impossible to get, especially with the head gasket also being metal and still only 1mm thick for strength. I was very impressed when I saw this finished. Looks very tough, and you can clearly appreciate the bite it must have into the metal gasket locking it in place.
The rods are 2mm shorter than factory micra rods all in the aid of improving strength. And as you can clearly see they are much larger and thicker all round. Jake from Jake's performance in Canberra was responsible for chasing these up and I am extremely happy with how they have turned out. As was the case with the pistons, no one in Australia had made anything like this before for a micra, so I left the design with Jake and PAR produced the goods. Considering they are also forged and started off as a solid piece of metal and have gone through a whole stage of processes to strengthen them, you can start to appreciate the high labour time involved in making these.
The pistons are 2mm taller and very very dished to drop the compression to 8.2:1. They look beautiful! Great work Jake's Performance and SPS pistons, although the wait almost killed me.
The coating looks brilliant. There were some tiny "crow's feet" here and there, just tiny lines/defects in the shiny finish which don't affect the underlying ceramic later, only the outer finish layer. So the guy gave me a $200 discount yay.
The coating was performed inside and outside which doubles its effectiveness compared to just coating the outside.
They have thought of everything with this one, the rail you can see connecting the bolts that clamp on the 3" flange to the double-dump is there to fix the bolts in place because its difficult to get your hand on that side of the pipe. So you only need to remove from underneath, then the entire 3 bolts and rail pop out the top as one piece. Nice touch eh?
Its a 2.25" dump with 1.75" wastegate dump, after that they merge into a single 3" mandrel section for about 60mm before being reduced into my main 2.5" exhaust pipe.
Just after being made and before the HPC matt black temperature coating was applied.
I got this japanese CG13DE from a wrecker in campbelltown and sent to Jake's when this rebuild started. We wanted to start with a fresh factory engine with low Kms to ensure everything was started fresh and clean. The engine when disassembled was not even worn and virtually brand new inside, Jake was very impressed even though the wrecker said it has "no more than 80,000km on it". Perhaps it had a lot less.
Here's the details of my engine bay stripdown which I delved into late September 2003. My aim was to learn a bit about the micra engine and particularly see if I could find out why my engine was blowing some smoke occasionally and cyclicly overheating etc.
Due to some weird symptoms going on with my car as well as some needed repairs, I stripped down my engine and some major components. I removed the head, turbocharger, dump pipe, manifolds and anything that got in the way. My whole attitude was to learn as much as I could and inspect everything to see where possible smoke and overheating problems could be coming from. I've now got a slightly better idea of the guts of the micra engine and how everything fits together (allthough I haven't had the block apart yet).
I'll be getting the engine rebuilt professionally with forged pistons, 2mm head gasket, new exhaust manifold and new double dump pipe etc. I'm hoping to run around 14-15psi constantly and reliably - this should make the car pull pretty hard as long as its reliable. There are a heap of Japanese micras running 1 bar (14psi) of boost, so we should be sweet - especially with forgies and a nitrated crank and nitrated rods. I'm also having a major tidy up of the engine bay, any messy wires and tubes will be all cleaned up so that it looks great but also is easier to work on and maintain once its all back together.
Some interesting things that I discovered were:
Overall, I think these internals so far were in pretty good condition. The problems I've been experiencing could be attributed to a few things I guess, but I'm very glad that I've pulled it all apart and now know exactly what condition everything is in, and I have a perfect chance to replace anything that's damaged or insufficient while its all apart!
Anyway, here's a heap of photos that I took which may be useful..