hi jayell,

your best and safest bet would be for you to RR your car
with different boost levels set , eg , at .8 , 1 and 1.2
bar and have the fuelling checked at each level.

That way there'd be absolutely no guessing.

weather conditions , fuel - all have a big influence. Both
of us are resident in very HOT climates , thats a very
big factor.

cheers.

<img src="/forum/images/graemlins/smile.gif" alt="" />

I will do, definitely, but to be honest I was looking at running 1.3-1.4 bar <img src="/forum/images/graemlins/wink.gif" alt="" />

Jayell - on your current setup 1.2 bar. You've got the cooling to run 1.3, but on the standard turbo you will get very little extra power and it will be under a lot of strain(all you'll get is a bit more torque mid range really) as it's not efficient at that level. I tested my car on a rolling road with an EVO FMIC and standard turbo at 1.2, 1.3, and 1.4 bar using a GTEC1 chip. I got less power at 1.4 bar than at 1.2 - proof that more boost does not equal more power in some set ups. 1.3 bar I got practically no extra over 1.2

To set your boost level on the PRV get the car in fourth gear at 2,500 rpm, then floor it until about 3,500 rpm - 1.2 bar should be the highest boost you see on the guage, though a brief spike higher is OK (this will depend on what PRV you use). You'll find you get about a bar of boost in 1st / second gear with the PRV set like this - which is both normal and fine. You'll hold about 0.6 bar at the redline - which you can't change due to the turbo / actuator and lack of electronic boost controller.

On your future set up the GT28R will still be efficient at 1.4 bar or more <img src="/forum/images/graemlins/crazy.gif" alt="" />, which is what boost I will be mapping my car to later this month.... however fuelling with a plug and play chip at this boost level is a bit hit and miss IMO. This is why I'm going for a unichip - without a unichip my personal opinion would be to stick to 1.3 bar for safety.

You'll have a Blitz controller at this stage so you'll be able to play about with the boost at the redline. I would advise you to run either 1.0 bar or 1.1 bar at the redline - you could run more, but there's more risk + wear to the engine. Your new turbo should have the 0.8 bar actuator, so it should hold this level without much help from the controller anyway. As you hold more boost you'll also need more fuel at the top end of the rev range - which in theory the GTEC1/2 should provide, however dont risk trusting to luck - get the car's fuelling checked on a rolling road after modding before giving it some beans at the top end in 4th or 5th gear - if you then need more fuel GrahamL can get you a chip that will supply it for you. I'd reccomend a unichip custom map at this stage of modding both for power and safety.

A final point re the walbro 255 fuel pump. You need to check the voltage the O/E wiring supplies to it under load - if it drops to about 9v then you'll need to modify the power supply to it as it can't supply enough fuel at this reduced power supply. This is a contentious issue which I'm still trying to research, and I do know cars that run 300bhp on the standard pump and wiring with no problems. For more info on this issue:

http://www.fiatcoupeclub.org/forum/showflat.php?...&PHPSESSID=

http://www.fiatcoupeclub.org/forum/showflat.php?...&PHPSESSID=

I'd advise you to check the voltage at the pump under load (4th gear 2,500 revs - floor it to about 4,000 revs - get a voltmeter on the power supply to the fuel pump via your ski hatch whilst doing this. You'll need a mate to check this whilst you drive....)

Shout if any of this is unclear - am typeing pretty quick!

Si <img src="/forum/images/graemlins/smile.gif" alt="" />

Some off us also change the spark plugs after installing a G-tec chip. I use NGK BKUR 7ET, a little bit colder than standard ones.

Si, thanks very much for taking the time to write that, that's really helpful. With the new fuel pump I will have the garage undertake the dedicated power supply anyway, it seems like a false economy not to have this done, even if it may not be necessary.

GrahamL has sent me two different versions of the GTEC 2, and like you say, I will definitely have the car RRed to see which one is the most suitable.

Thanks again mate <img src="/forum/images/graemlins/smile.gif" alt="" /> <img src="/forum/images/graemlins/smile.gif" alt="" />

no worries - you're going to have some fun when that new turbo arrives. the top end will be far far stronger than with the standard turbo and FMIC! <img src="/forum/images/graemlins/laugh.gif" alt="" />

New turbo is currently keeping the cat food company in the cupboard, I now have to wait for the DP to arrive <img src="/forum/images/graemlins/frown.gif" alt="" /> I hate waiting and now you've just made it worse <img src="/forum/images/graemlins/wink.gif" alt="" />

I know it's a how-long-is-a-piece-of-string question but it has to be asked - predicted bhp ? Would it begin with a 3 ? <img src="/forum/images/graemlins/laugh.gif" alt="" />

At 1.4 bar my guess would be 280 - 310 bhp. You should get 300bhp+ easy with a unichip map and that boost level on a GT28R. <img src="/forum/images/graemlins/smile.gif" alt="" />

Thanks Si, to be honest I'm still recovering from open wallet surgery from the turbo, EBC, DP, fuel pump and chip so as long as it's safe, I will put off the Unichip for a little while if I can <img src="/forum/images/graemlins/smile.gif" alt="" />

When people on this forum first started to run PRVs with standard chips (a few years ago now!) most could set them at ~1.2 bar without any problems. There are different versions of the Gtec1 chip - the 'standard' 1.2 bar version has the standard fuelling map and is fine as long as you aren't tempted to push the boost up any further <img src="/forum/images/graemlins/smirk.gif" alt="" /> Most coops running a standard T28 turbo will fuel 1.2 bar without having to uprate the pump but if you are worried it might be worth getting the fuelling checked on a RR. The other thing worth checking is that the voltage at the pump is ok - some people have had problems with a voltage drop causing the pump to under-perform.

good post Suba.

thanks.

.

You don't need a PRV to run at 1.2 bar with a Gtec1 chip. It was originally designed to be used as a 1.2 bar plug-n-play chip with the standard EBV. By adding a PRV you are actually taking boost control away from the chip. You need to be aware that by removing the EBV you are also losing some of the in-built safety features <img src="/forum/images/graemlins/shocked.gif" alt="" /> .People started using PRVs with these chips for 2 reasons..1) To control overboost which can hit 1.6 bar <img src="/forum/images/graemlins/shocked.gif" alt="" /> 2) To prevent boost leaking past the wastgate actuator until max boost is reached.

The GTEC does not overboost to silly levels like the novitec (1.8 bar at times) - 1.4 bar tops.

the main reason for using a PRV is that the EBV is crap. It can't react fast enough and the boost control is therefore poor. On my car I found the boost fluctuating up and down in fouth / fifth gear with the gtec and EBV - it felt awful. the PRV fixed this issue, and lots of coops have found this to be the case - not just me.

With regard to safety - if the car detects a problem it will go into 'limp' mode (base boost only) there is also a sensor on a standard coop that will vary the boost pressure according to altitude that relies on the EBV as far as I'm aware. Both of these are negliable on a well maintained car - and IMO the gains associated with fitting a PRV / PBV / boost controller outweigh the drawbacks.

yes , suba is right.

when I went with my open pod , decat and the chip , the
EBV was totally overwhelmed and could no longer 'keep up'
with the throttle/boost. I was getting a boost spiking,
pulsing ..... which was a real joke.

installed an electronic boost controller - problem solved.

before , without the Profec , the standard GTEC V.1 was
overboosting (on my setup) , to about 1.4 - 1.5 bar. This
is borderline safe.

With the Profec , I dail in 1.2 bar and the boost needle
doesn't waver and no overboost.

cheers.

<img src="/forum/images/graemlins/smile.gif" alt="" />

It's good to fit PRV with EBV in parallel configuration to protect overboost issue? how the drivebility if parallel configuration is configured?

Yes – you could do that to eliminate the overboost – but that’s all the set up would do. You’ll have the EBV controlling the boost and the typical fluctuating boost level that normally accompanies it. In my opinion go for the PRV by itself. You can always try the EBV then PRV then both to see which your happy with…

Do you all recommend the GTECH 1 chip then ???? <img src="/forum/images/graemlins/laugh.gif" alt="" />

cheeky fella ..... haha .... <img src="/forum/images/graemlins/smile.gif" alt="" />

I'm well aware of the reasons why people fit PRVs - I just thought it was worth pointing out that replacing the EBV isn't essential when fitting a Gtec chip and that doing so isn't without its dangers.

just as a note , I just took my coupe out for an extended
open highway run and with my mildish mods , I can hold
1.1 bar easy.

blip the throttle a bit and I get the 1.2 that I've set
at the Profec.

wonderful thingies.

is it safe to run the GT28R turbo and use the standard coupe chip?

its about the boost levels that you'll be running.

if you're using the standard Fiat chip , then you can
run any size of turbo and it'll still be safe , since the
stock chip is 0.8 bar , thereabouts.

if you want to run higher than stock boost , then a new
fuelling setup (chip/FPR/pump/injectors/etc) will need
to be considered.

cheers.

Cool... just the answer i needed. <img src="/forum/images/graemlins/smile.gif" alt="" />
Thanks