recommended spec......

[pegliobaglio]

Right chaps,
I am almost done with my chassis upgrades now, was just wondering what sort of cost and spec I would need for a solid reliable 350-400 bhp. As hopefully will start accumulating parts soon ,just wondering which parts are tried and tested,and if there are any suppliers/parts companies I should be wary of. Any info will be much appreciated! Thanks for your time
Chris

 

[LuPix_S15]

I think as long as the engine's still relatively fresh and lively then internals wise you're perfectly fine with stock. But unless you want a much bigger turbo than the normal upgrade ones (which I'll mention later), you'd probs need uprated cams like the Tomei 256 deg ones which will lift horsepower a bit higher at the top end etc. If you're planning on this it doesn't hurt to get the head sorted with new springs, MHG and rocker arm stoppers as extra precaution

Other than that you can achieve 400 bhp or near enough with a Garrett GT2871R turbo. You can even go for the more responsive smaller 0.64 AR version which comes on boost early so will still drive and respond similar to stock S15 tubby. Supporting mods must include the usual uprated fuel pump, FMIC, colder plugs, Z32 AFM, 740cc injectors and a remap with something like the Nistune which is very popular these days :thumbs:


Edit: forgot to say IMO if you're going above 350 bhp then it's best to get a much stronger gearbox sorted as the chocolate S15 6 speed is asking to breakdown when you get to 400+ bhp!! I'll be getting an RB box conversion BEFORE I even attempt to get a new turbo and power/torque above 350

 

[pegliobaglio]

Cheers buddy! Have already been eyein up the tomei cams!arp bolts and nismo mounts too, Do you really need the afm?or can you cut it out completely?am looking into the apexi power fc too,wanna get all the basics sorted, then consider the turbo after,as you said. Already sorting the bigger rad and intercooler,and the engine only has about 40k miles on it so should be pretty sweet still. Not really gonna chase figures more after something I can really use as won't be tracking it much tbh. Will keep an eye out for your evaluation of the rb conversion,thanks for the info dude,gives me a nice basis to start looking!

 

[craig8585]

Don't forget your brakes. When you get to 300bhp you will soon see the standard brakes are not enough.

 

[LuPix_S15]

^^^ +1 which is why I'm getting some K-Sport 330mm upgrades hehe


peglio - without the Z32 AFM you won't be able to get more than around 320 bhp max! Needs more airflow so if you tune yours like mine - up to 1.2 bar stock turbo and stock injectors then 300 bhp or a little over is the norm. Injectors are the first to max and then the AFM. So if you want 350+ then you gotta get it all :wack:

 

[Fruitbooter]

It sucks that the gearbox is the weak link when tuning as it sounds like a right pain to upgrade it to something stronger such as the RB.

It is good however that you dont need to do THAT much really to get good power! IMO the S15 as standard is fast! But that might be becuase im not used to the power yet? But im sure ill be happy enough with 300bhp tbh..but as i want to do some drifting and track driving I see the gearbox as a being a bit of a risk so will proberly have to go down the RB route myself in years to come

 

[pegliobaglio]

Yeah sorry meant to say have already chosen my brake upgrade the standard brakes are not enough even now,going for a brembo conversion I think should be enough as I don't intend to track her.
Needs must then,was just not sure if you could get rid of the afm altogether If you have a stand alone ecu.
Prob be cheaper to get the z32 ,in which case what filter should I get?I am trying to keep the whole car colour coded so Am looking at the blitz sus power intake.
Wanna do it once and do it properly so if I have to wait a little longer to get everything together then that's fine by me.
Does everyone use nismo injectors and is there any benefit to running a top feed set up with a rail? Are things like intAke plenums only worthwhile if chasing high power figures?
Cheers for the info guys!

 

[LuPix_S15]

Yeah the gearbox is one of the only major weak links but it really does depend on the power/torque combined with driving style and use...

I think as soon as you go over 350 bhp and there's regular clutch kicking or launches (drift + drag etc) then it's deffo worth doing as I get the impression it's not 'if' but 'when' the box will die :wack: I've got a complete quote from Garage-D who will do the conversion including sourcing all the parts I need and will warrant the box if they source this themselves. Will be around the £1600 mark. This also includes ~8 hours labour charge as well. But recently I've seen Polo on Driftworks advertise all the bits for RB box conversion and including a ~60k mileage mission he wanted £1000 or £1200 fitted

But since my stock box is making loads of horrible noises now I'm gonna get this done before I do any further power/torque upgrades. Just seems silly to make her faster and then for the box to give up the ghost and leave me stranded somewhere!!


peglio - you can bypass the install of Z32 AFM but you'll need a MAP sensor and the correct Apexi PFC or alike to do this. However always got the impression this was only necessary for very big horsepower applications where none of the MAF sensors can detect any more airflow...

Just go for Nismo 740cc if you're aiming for around the 400 bhp mark. Anything else including fuel rails etc won't be necessary

 

[pegliobaglio]

Cool man,well I now have a little shopping list together ,hopefully start building up the bits after the big expense that is xmas! Just nice to know what I need now I can start shopping around and collecting bits and bobs if I find some good deals,cheers for the help matey!

 

[ichigo-300]

Just out of interest I have a Z32 MAF with plug that I'm going to sell for £80.00 if your interested, I bought it to do the upgrades that Lupix has suggested, but in the end got a deal on a HKS Fcon V Pro which i've bought with the map sensor etc, so won't need it now (I literally only bought it 2 weeks ago but plans have been a changing!! ).

PM me if you interested (I know it's not the right section for sales but I've not even thought about putting it up for sale yet)

 

[pegliobaglio]

If its geuine I will defo have it mate!!!!! Will pm you .

 

[ichigo-300]

Yep it's legit, bought it from a guy on Driftworks, send me a PM and I'll send you some photos with the label etc.

 

[LuPix_S15]

grrrr I'm too late... I need a Z32 MAF lol!! :wack:


Awesome - glad to see asking about tuning mods has helped you source a part you need haha :thumbs: