I thought this might be interesting to a few folk. Following my RR session on Saturday I got the opportunity to run a direct comparison between the GTEC and standard chip. Both were running near identical boost levels, the first run was setup as GTEC/EBV and the second as Standard chip/PRV.

Here are the results.

As you can see the power curves are nearly identical with a slight advantage of 2hp being developed earlier in the rev range with the GTec. More interesting is the fuelling curves:. You can clearly see the GTEC is running much richer in the 3000-4000rpm range but as the curve goes past 4500, they swap over and the standard chip fuels more. Running too rich robs power and it seems that the GTEC actually reduces fuelling in this rev range to make more power.

Overall I seem to be running too rich in both cases, so the GTEC does nothing too improve power for my car. This being the case I've returned to the standard chip and set up 1.2 bar on my PRV.


Any comments on this, guys?. Graham if you are reading, a tech explanation of how the fuelling is setup in the GTEC would be great

When I swapped chips around I noticed it would take a good few miles before the ECU learnt all the new settings and adjusted its self to run them correctly, the boost especially was all over the place, at first it would only give 1 bar then it slowly raised up to 1.3. Not sure if this is the case on your car Cosmo but maybe it didnt have enough time to adjust ?

The lack of learning time struck me too whilst I watched Highwayman pop out chips inbetween runs whilst still strapped to the rollers, one or two others did the same thing And cosmo you even switched from PRV to EBV

Using only PRV on a Turbo car is never a good thing, no.

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And cosmo you even switched from PRV to EBV

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Other way round Dave. The idea was to match the same boost as level as the EBV/GTEC but with reduced fuelling as I was running too rich.

Im a bit of a sceptic on this 'learning time' issue. I hear what you are saying Jimbo but I think everyone who swapped their chips on the day saw some fairly radical changes, instantly. Especially after some fairly scary results coming from those running the GTEC II.

In any case there was no issue with learning time on boost because I started with the EBV and then fitted the PRV. The boost curve and power curve was near identical for both runs so the only change was in fuelling.

can the standard chip fuel for 1.3 bar?

So your saying its safe to run on a standard chip and a PRV at 1.2 bar ?? and the standard chip fuels it ok

Its only safe on my car as its running rich already. The graph shows the GTEC pumps more fuel in at the higher boost level but tails off to release more power higher in the rev range. In my case Im not getting that extra power because of the rich AFR so there is no benefit from using the GTEC for me. What I need to do is find out why my fuelling is so rich or get it Unichipped. I suspect that a lot iof cars are njo different and the standard chip will fuel fine to 1.2bar. Always best to get it checked though.

This might be a silly question but how is the AFR measured on the rolling road? Is it at the exhaust exit or is it lambda based or what?I have had several rolling roads here and never have i gotten an AFR measurement :O

might be side tracking this topic but....is there any point in me getting a switchable boost controller to switch from standard boost to 1.2 or 1.3 bar if i have a novetec chip which is 1.1 at full boost? or is it just pointless?

cheers Meagy

Meagy I think you are getting a bit confused. If you fit any external boost controller, PRV or electronic, the chip no longer controls boost only fuelling/ignition parameters. Any boost parameters in the Novitec or any other chip are completely ignored.

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This might be a silly question but how is the AFR measured on the rolling road? Is it at the exhaust exit or is it lambda based or what?I have had several rolling roads here and never have i gotten an AFR measurement :O

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The whole point of a RR is to check your fuelling. Surrey Rolling Road use a heated wideband lambda sensor that fits into your exhaust exit.

List your other mods for us Cosmo so we can work it out, do you run an uprated airfilter and exhaust with de-cat, plugs, etc ?

cheers cosmograph! confused aint the word lol

OK here's the list:

Run No. 1 (Blue trace)

Pace WMIC,
GTEC1
EBV
K&N panel filter/ slightly drilled box
95 octane fuel (Morrisons finest )
Standard NGK plugs
Scorpion cat back exhaust


Run No.2 (Red trace)

As above with

Standard Chip.
PRV set at 1.2 bar ish (the boost level was set to that achieved with the EBV, boost and power curves nearly identical)

Cosmo - was it you that had the starting problems also after swapping chips? That would also point to the Ecu not having time to reset properly?

Plus I'm sure the Gtec1 should be run with 97 Octane+?

Yep that was me . I think the starting problems were due to the ECU shorting out with the metal cover moving around loose in the footwell. It was causing the key code to come up on the dash.

Fairly sure GTEC1 is 95 RON.

Interestingly my car has been runing much smoother since I put the standard chip back in. Much better pick up from low revs.

What were the alarming results for te GTEC 2? Running the standard chip and a RamAir filter my car got 249bhp. I want to chip it and like the idea of using the gtec stuff?

IMO, if you are getting 249bhp and fuelling OK with your standard chip its pointless going for a GTEC. The only way you will improve on that is to fit a different turbo/intercooler then you might need more fuel to support it.

Highwaymans car ran lean on the RR with the GTEC2 but was fine with GTEC1. See the post in Rolling Road section.

OK, here are my graphs from Saturday:

Power/Torque
Fuelling
Boost Pressure

The red line is with the GTEC2 fitted, and the pink line is the GTEC1 .

As you can see, the power and torque curves are similar, with a slight drop off between the two chips. The fuelling graph, however shows the GTEC2 running quite a bit leaner than the GTEC1. Whilst it is spot on at higher revs, it is worrying lean lower down.

Phil

...And so rests the case for a hot chip, vs. a proper re-map or a Unichip....or for the rich peeps, a Motec.

Each and every car will respond differently to a tweaked chip, some results good, and others, not so good.
Early on in my Coupe ownership, I bought what I thought was a Novitec chip off Ebay – turns out that it was a GTEC1. It was one of the first mods I did while I was still running with the EBV and you could feel the difference straight away. Obviously, most of the gains came from the increased boost pressure, but you got the feeling that the chip had done all the work.

Many mods later, including an Apexi boost controller I finally got down to Surrey RR and got it on the rollers. Fortunately, my fuelling was fine albeit slightly rich up the top end, but it could have easily been a disaster story – with a blown engine as the result.

The only way forward for me now is a proper map, which is why until I’ve either cracked re-mapping the standard unit, or can afford a Motec, I’m going for a Unichip – as this is really the most logical way of getting my map tailored to my car.
Even if one of you had the exact mods that I have, the fuelling would still be different, so putting in a performance chip is always going to be a gamble.

Bernie.

Yes I think everyone who had their car on the rollers on Saturday has either booked, or is saving for, the Unichip mapping.

Just catching up with this thread...

There's no doubt that it can take time for the ECU to re-learn the new boost parameters when fitting a different chip, if still using the EBV to control boost. I've seen some coupes settle down to consistent boost levels more or less instantly, but others have taken hours or even days for boost levels to become consistent and stop "see-sawing" between sustained and overboost levels. And occasionally they don't settle down at all and sometimes boost continues to bounce between sustained/overboost levels at full throttle, in which case fitting a PRV or a custom mapped chip with slightly higher overboost is the only solution.

On the learning of fuelling maps, I'm not sure... don't think anyone's done any serious testing to find out how that changes over time. Certainly from what I've seen with the basic in car air/fuel ratio meter "full throttle" fuelling doesn't change much (if at all) over time as the ECU adjusts to a new chip.

So, if you're running a PRV or electronic boost controller I don't think you'd get any *major* inconsistencies with the dyno results by switching chips and testing immediately, so long as they give it a few warm up runs first. But, if you're still using the EBV to control boost then there's a good chance your boost (and therefore possibly fuelling?) will be erratic at first so I wouldn't expect accurate results from back to back dyno runs with different chips.

Gtec1 v's standard chip... the biggest gain definitely comes from the boost increase, so if you're using a PRV to increase boost with a standard chip then there won't be a great deal of difference power wise. Fuelling and ignition maps are changed (as well as the fuel cut point, but unless you use a bigger turbo that's rarely an issue), but only slightly, so I wouldn't expect to see any more than maybe 2-4 BHP increase. I've always said to guys running a PRV with a standard chip that they won't notice much (if any) difference with a Gtec1, if their fuelling is OK at 1.2 bar. Sometimes changing to the gtec1 (or higher fuelling gtec1) can improve fuelling though, but obviously that has to be determined on a rolling road.

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Each and every car will respond differently to a tweaked chip, some results good, and others, not so good.

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Absolutely right.

As we've seen some cars are running rich or lean even with the standard fiat chip, so there really is no substitute for having fuelling checked properly with a wideband lambda sensor. In most cases the fuelling will be acceptable with any chip, but unless you're very lucky they won't be as good as a unichip specifically custom mapped for the particular car.

On initial tests (on around 8-10 coupes) of Gtec2 none were found to be running significantly lean or over-fuelling, but from recent dyno tests it seems some guys are having problems with running dangerously lean. As with gtec1 there'll have to be a higher fuelling version of gtec2 as well, which will be available very soon.

It may be that I have to supply both chips (normal and higher fuelling versions) if someone is upgrading to gtec2, so they can have both tested together and use the one which best matches their car.

Great post graham. This clears a lot of things up in my mind. Could you just explain how the GTEC1 fuels vs the standard chip.?

From what I could see on the RR the GTEC fuels more at 3000rpm or so to support the higher boost but actually reduces fuelling higher in the rev range to generate a leaner mixture and more power. Is this right?

I think I have some good data for comparisons as on my second run the boost was fixed with the PRV so no ECU learning required.

Here is my graph from the RR. I was running the standard chip with my blitz controller.

my results

The Red line was at just under 1.1bar which gave 233bhp.
The Blue line was at 1.2bar and gave the 247bhp. The more boost I ran, the richer it got.

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can the standard chip fuel for 1.3 bar?

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Well, my car ran on the standard chip for approx. 3-4 years with a PRV set at 1.3bar (indicated) and (clutching lucky heather) had no problems. I've changed to a GTECH1 now.

I didn't really notice a performance increase, but what I did notice was a driveabilty (if that's a word) improvement, especially off boost. It's made a HUGE difference to the way the car behaves, it's much nicer to drive, ironically particularly at low speed!!

After my new engine and turbo last year I'm now getting a Unichip fitted to get my fueling correct once and for all. Looking for safety, driveability and reduced paranoia rather than large bhp figures. (Although I am still expecting a small increase to say 260bhp at 1.2bar with my Superspool turbo). I'll get them to first do 2 power runs, one with the standard chip and one with my GTEC 1 chip to see which one they think will make the best 'base' map.

cosmo (and others) - you really need a decat to measure fuelling accurately.

im sure you already know that, but personally i would ignore those fuelling graphs whilst you have the CAT in place.