This is my set up :

S4 13bt engine, Rebuilt, Mild port and secodary bridge.
x4 550cc injectors,
S5 stock turbo and manifold,
2inch intercooler piping with S4 I,C
Stock S5 dump pipe with 2inch exhaust.

Now the car runs fine but i want a bit more power, idles/braps at 1900rpm, Smooth as to drive, Full boost about 3g, But its only boosting about 6psi max, and by 6500rpm it falls flat on its face, So what i want to no is how do i get some more revs out of it and more boost ?

1) Boost tap ?
2) Bigger exhaust ?
3) Bigger I.C piping and I.C ?
4) Could i use a T3/T4 front compressor cover and wheel ? or what could i use ?
5) Would it pay to get the waste gate ported ?

I will be upgrading injectors an fuel supply soon, Not after a mega HP machine, Just a bit more than what ive got, 250-300 hp atw would be nice.

 

upgrade your fuel system first.

 

your injectors are too small, going to recommend rtek 1.8 and 4x720cc and a rewired walbro 255 before you touch the boost pressure. the boost will fall on its face because of your engine porting, even with a boost controller at 12psi...you will only see 6psi at redline.

also you REALLY need a wideband display...you may already be running lean at 6psi with that port job.

 

injector and fuel pump is always recommended.

 

fuel system first..

more boost? get a 3'' exhaust instead of 2", that will help a lot...
you will def need a fmic.
but the stock turbo is too small, so you wont make full power right up to the redline, but you will need to port the wastegate to avoid creep!

 

Mint, Thanks people, Im running a microtech and have got a small bosch pump in there at the moment, Probably upgrade to a Bosch 044 or 910 pump ?,

I did have a wide band in there when i got it road tuned, the a/f's were from memory, 10 at idle 11-12 under boost, 13 cruising.

The S4 top mount intercooler has been converted to front mount to, But maybe its too small ? Also does anyone no if the RC injectors on e-bay are any good ???? was just going to replace the secondary ones with 1000cc or 1200cc or even 1600cc .....

Is the S5 turbo good for 250 - 300 rwhp, Or what mods need to be done to the turbo after fuel supply etc is beefd up ?

Cheers.

 

i have almost taken the S5 turbo to as far as it can go on a stock motor, and 250rwhp is pretty much it. boost drops off quickly at higher revs...

get bnr turbo or other aftermarket

you need around 13 at idle, or whatever makes the car idle properly.
around 11 at 14psi and with cruising you would want around 14

 

044 is overkill for this power level

 

what about the rc injectors as im curious about these too

 

(FURB) - So is your turbo stock ? Boosting 14psi ? making 250 rwhp on a stock block ? Thats mint.

Yea its 10 at idle any leaner it hates it bad, Starts mint hot or cold an just pulses away. When it was n.a it would rev out to 8000rpm easy an seem to be still making power, Now ha, no way near it, so eaither need to get my turbo high flowd or a new bigger turbo, Before i do that tho, i will try a bigger exhaust, injectors, surge tank and pump an retune then will see if that helps much. Cheers.

 

So a 910 will be fine then or a walbro 255 ??

Yea the RC injectors, Does any no what they are like ?

http://cgi.ebay.com/ebaymotors/RC-Fu...Q5fAccessories

 

Yeah, but i got everything else covered...
Racing beat exhaust, fmic, fd uim and tb, entire intake portmatched, ported wastegate, proper functioning cai, intake system pressure tested for leaks, powerfc with mapsensor instead of afm and so on...
pretty much all restrictions improved as far as possible with stock engine

But then....

It is clear that stock turbo is too small..!
Boost climbs like crazy at 3500 up to 14-15psi, but When Revving over 5000 boost slowly drops back to 8psi at 7000.
Tried uprated actuator and avcr finetuning, but that only affects boost down low, turbo just cant flow that much at higher rpms.
If the turbo can flow more (like with the bnr stage 1) you can get to 280rwhp for relative low costs.

I am upgrading to stage 4 and shooting for 375rwhp...

 

[QUOTE=Furb;9805350]Yeah, but i got everything else covered...
QUOTE]

Seems like it, Thats still good tho, What size is your intercooler an piping ? And who sells the 720cc injectors everyone uses on here ?

 

I have the RC 750cc high impedence injectors in the secondary and the car (S5 Turbo) runs very strong. Haven't noticed any problems with them. With the following combo I hope to dyno at around 260-270 whp @10 psi when the ambient air density is a bit lower. Dynoed previously at 222 whp @7 psi with just the first three mods and ported wastegate. Think Spring.

RB REV-II exhaust system
HKS intake
S-AFC

BNR Stage 1 upgrade
Supra TT fuel pump
RC 750cc secondaries
Rtek 1.7-chipped ECU

 

[QUOTE=S1sevenNZ;9805960]standard sized IC, about 60x30x7,5cm with 2,5" piping
i had the greddy 720cc's from rx7store.net

 

Took the words right out of my mouth.


It may just be the "spend more money" in me talking but i'd upgrade to an external wg/t4/large t3 as soon as you get fuel in check. Maybe not for the boost but to take full advantage of the engine you've built. I feel stock hotsides are great for just that, stock....or close to it. A bigger hotside will make more top end power and actually hold boost with your engine. Think full frame t4 60-1, to4b, gt35r, t70....etc..... You could even run a holset super hx40 and still let the exhaust breathe well and have a really good powerband for cheap. You can get blown hx40's for $80 shipped on ebay and buy new wheels, bearings and seals for about $170 and have a bomb *** turbo for under $300.

 

.

Somthing like this ?

http://cgi.ebay.com/ebaymotors/EMUSA...Q5fAccessories

 

[QUOTE=Furb;9806316]Thanks furb, Will go have a look.