Calvs Tuning Quest: Skyline R33 GTS25t

[Calvin]

Hi Everyone
I am new to the forum and am look for help. I have a R33 Skyline GTS25T and am looking to modify it (make it faster). Here in UK I am getting lots of conflicting info regarding tuning. All the info available seems to be GTR related. I would like to hear from people who have been down this road and can give me some good advice. I will keep the progress and results posted. Also a good parts supplier in the UK.


Calvin

[moondog]

filter and exhaust should help; bigger intercooler, as the standard one's almost big enough to use as a paperweight; increased boost (but not too much, otherwise you'll hit boost/fuel cuts); some sort of programmable engine management to tune the fuel and ignition. I don't know exactly how much that'd net you, but it ought to be quite a bit better than standard - I certainly hope so, as at this point I don't intend going further than that myself.

I'm sure our UK friends will be able to assist with suppliers over there.

[Revhead]

Get a full 3" exhaust system. That'll release a few extra hp, I dunno exactly how many but mine went noticeably harder with only a new exhaust. Next get a pod filter, an actual performance improvement (tried swapping the stock airbox back in and the car went HEAPS slower) and as an added bonus the turbo and stock BOV are FAR louder!

Then get a wastegate bleed, set it to 10-12psi and you should be in the high 13s if you launch it right. Beyond that just check the obvious stuff, make sure it's serviced, static timing is set correctly, etc. I ran a 14.1@101mph with these mods and I had a really shitty launch.

After that you'll need to change the BOV (factory one leaks over 10-12psi I've been told), new exhaust manifold (stocker sucks over 12psi) and maybe even a bigger turbo, then get bigger injectors and aftermarket computer. A new intercooler is a must because the factory one is a piece of shite, and while you're at it change the plenum to a "throttle body at the front" type, to clean up the engine bay a bit

One of the quickest Skylines in Australia (40RCD) is using the stock 2.5L bottom end with forged pistons, and has put a T60-1 turbo, tubular high-mount exhaust manifold, big intercooler, custom plenum and aftermarket injection. He's running a 3-speed Trimatic and C16 race fuel and, on 28psi has run a 10.69@127mph, bouncing off the rev limiter in top gear about 20m before the finish line.

[Slip]

Hhahah what a well thought out setup.......

Whats wrong with 14psi?

[zapf]

Hello Calvin,
First question... how much $$$ are you willing to spend and how much Power are you looking for... at the moment. your 25T being standard will put out anywhere between 120kW~130kW at the wheels.

Cheers
Zapf

[whatsisname]

Originally posted by Revhead
After that you'll need to change the BOV (factory one leaks over 10-12psi I've been told)

Then I'd say you've been told wrong, I've run "upto" 14+psi (usually stick to 13) & have had ZERO leakage on the standard BOV, on a number of dyno runs (& on the road) I've had no change in the dyno curve & no drop in boost press' @ all. I've never run over 15psi ever though, so it maybe no good from there up???.

[Calvin]

What is a BOV, Sorry to sound thick but this is the first turbo car I have owned, but am learning fast! I took her for a tune at a local rolling road on friday, but his experience is more with Cossies and RS turbos, turbo technics etc etc. I got a nice result however, 270 bhp @ 6800at the flywheel, 190bhp @ the wheels! I thought that they were only supposed to be around the 245bhp mark, I have attached the dyno print out, what do you think? is this accurate? The only mods to the car as far as I know is a HKS pod filter I fitted which improved fuel ecomomy no end and a Super Dragger back box, otherwise he says the car is totally stock. I asked him what mods he recommends, Everyone says larger intercooler raised boost etc, He said larger turbo and a chip, raised boost and I ought to see about 330-340bhp forget the intercooler as the larger turbo will create less heat, what are your thoughts as I am fast becoming confused. This guy definately knows his stuff but his experience does'nt cover Skylines.

Calv:flash:

PS cant get the dyno scan to attach sorry how do you do it when the only valid file extension is .txt? and how do you convert bhp to kw?

[Calvin]

I dont mind spending £2000 on it but where would it be best spent?, I want as much power as poss with reliabililty as I use it every day for work!


Calv

[zapf]

Hi Calvin,
In this case you want possibly the following...

- 3" Manderal bend exhaust. Locally made should be cheaper... or Jap one if you want to spend the money

- Some form of boost control, I suggest a Apex-i AVCR or the new Blitz Boost controller. [What year is your car? is it a Gen 1 or Gen II R33?]

- Intercooler if you have money left.

Keeping to about 12psi boost MAX with a Gen II or 14~15psi MAX with a Gen I, you should have a fast and reliable car. By running higher boost, some minor issues with your car could show up. In the form of misses. In which case could be one of the following things....

1.) gap spark plug to smaller gap. E.g 0.8mm
2.) Fuel pump failing.... New pump.
.... or others...

so set aside some money to get the car running good as well.

Cheers
Zapf

[Calvin]

The car is a 1994, this is Gen I isnt it? Will the standard ceramic turbo stay in one piece running 14-15psi? What stage does a new intercooler become a must?

Cheers for the info

Calv

Still cant attach the dyno printout

[moondog]

Originally posted by Calvin


PS cant get the dyno scan to attach sorry how do you do it when the only valid file extension is .txt? and how do you convert bhp to kw?

go here, and it will explain. You can upload a file and then link to it.

[Calvin]

Anyone else got any good advice?:grey: