Thursday, February 2, 2012

Car project Nissan Skyline

I have been running a little bit of car project over the last year or so. I found it quite fun fiddling around with bits and pieces.

The car is or was a relatively stock auto Nissan Skyline GTS25t R33 4 door. I bought an auto for the wifey who preferred driving them.

Some of it's features are:

- A 4 wheel steering HICAS system
- I put some 18" second hand mags on it :D
- It has an RB 2.5L single turbo engine (Rb25det), a little brother to the famous twin turbo GTR (RB26dett engine). Interestingly the RB25det engine which I have, is actually de-tuned so that it would not compete with the upper market GTR which has the Rb26dett.

Here is a youtube example of the power an RB25det can release.

And here is a heavily modded skyline at 1100hp

With reliable power of up to 260 rear wheel kilowatts on stock internals (many are tuned for higher output), I thought this car was a good base for a project. At stock they start with 185kw at the flywheel which is about a grunty 130rwkw ( with an auto), a manual about (140rwkw). The turbo runs a 7psi boost into the engine which is compressed air to allow better (more intense) combustion.

I have no intention of wringing it out to those ridiculous power ratios (260rwkw +) as I will have no need for that much power and will suck to many $ to upgrade all the supporting mods around the engine.

I started with getting a bigger 3" exhaust to remove any restriction for the engine to get rid of waste gasses. I noticed after doing this that the boost crept up to about 8psi since the engine could breath a bit better. After this the car needed a better fuel pump as these pumps are only designed for stock and cannot do much more than what they were made for. I installed a walbro 500hp pump which to this day goes well. The what was needed was a boost T which is a manual boost controller which allows me to bleed off air which then allows me to control the amount of boost the turbo runs at.

The stock turbo for long life reliably can only handle 10psi of boost (some people run more). But though it cannot run high boost, it does have a light ceramic wheel which enables a very quick spool time (The turbo reaches 9-10psi at low rpm). This makes the car very responsive and loads of torque down low.

 Now, the stock computer will cope with a little more power/load increase before it goes into safety mode and pulls back the ignition timing. So instead of retuning the stock Rb25det ecu which cannot be tuned very easily, I went for a Z32 ecu. This ecu was tuned by mail order by tuner in Auckland, but as I found out through trial and error the car was detonating at high rpm so a proper dyno tune needed to be done.
Do it once do it right.

So we dyno tuned it to a decent 168rwkw on 9-10psi of boost in Auckland.

 and found the reasons why it was pinging. It was partly timing and partly the little side mount intercooler (which cools the air coming from the turbo) was getting hot enough to fry an egg. So as intake temperatures rose detonating occurred. So I decided to get a front mount intercooler off a Mitsubishi Evolution IV since these intercoolers are larger, apparently flow well and fits real nice behind the crash bar. With that now installed it will be running a little more power and is safer for the engine on hot days. I am pretty confident there was not a heavy amount of damage to the engine since when it was pinging/detonating there was a lot of petrol going in, enough to dampen the effect.

So now everything is running pretty good these days, though second gear is slipping a little at times, just showing wear and tear for its age I guess and becoming obvious as I up the torque :D
I also had to change the radiator myself for a turbo one since there was a non-turbo version in there (WHO KNOWS WHY) and it was struggling to keep the engine cool. Temps were rising to 94 degrees C, partly due to the small radiator that should not have been in there and partly because the previous owner hadn't flushed the coolant regularly and so it got blocked.

All cheers to the Rb motor for what it gets put through by me :) It was slightly over heating with that little radiator for who knows how long, I didn't get it tuned right at first so it was pinging, and then there was the time when I had a leak in my boost gauge and accidently ran 20+ pounds of boost into the engine lol. Poor thing. You live and learn, but it still purrrs today.

Bullet proof they say? I would say pretty close.

... and one day down the road I might take it from stock and run a bigger turbo to crack the 200rwkw + mark. Not that I need it but it is simply a fun project. Huge learning curves has made it well worth it. I am pretty confident to work on a lot of areas on the car now without a mechanic... still with a fair bit of head scratching I might add.

Stay tuned :)

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