colt ralliart - first test drive of a turbo car

[chrissn89]

I believe that it would come down to your driving style quite a bit. Driving a N/A and a turbo car is very different. When you say driving hard, was that flat foot?(wide open throttle = WOT) Power delivery is totally different in a turbo charged car. Its hard to explain in words, well for me it is anyways.

Basically when driving a turbo car, you have on boost and off boost. Off boost is vacuum, which means when idling/cruising and driving soft you engine is running on a vacuum = engine sucking in air. The turbo can boost the air pressure to atmospheric pressure and still not be on boost. This allows the engine to have as much or more power than its N/A version and only using a little throttle. When going on boost the turbo forcing air into the engine. This can only really be done under WOT (wide open throttle) you are able to boost a little from atmospheric to about 4psi with out going on full boost.

Your best bet to fully understand this and the power delivery would be jump in a members or friends turbo car. If it has a PSI gauge with vacuum and boost will make it a easier to understand.

My Astra SRi-T has plenty of power low down with max torque (427Nm) at 2250rpm @ 17psi. 1000rpm = 290Nm @ 11psi


Hope that makes sense, probably not tho. Note this is taken from my car and my understanding. If im wrong please feel free to correct me.

[Wraith]

our second car kicked the bucket recently, so i've been in the market for a new car. last weekend my financee and i drove out to a dealer and took a look at a three year old colt ralliart.

its a little box car in the same style as the Barina. the cabin is surprisingly roomy and the rear seat can slide forwards and backwards - forwards to carry shopping, backwards to carry passengers. with the seat all the way back the rear leg room is really quite good and it would be comfortable for long trips. also it has 4 doors which is a plus plus in my books, climate control, and very nice recaros in the front

and then i drove it - and was somewhat disappointed? perhaps its because its the first turbo car i've driven and i had overly high expectations. when driving slowly shifting at 3k, it was a slug. so it's off boost. so i started driving harder, shifting at 4.5k - at that point you could start to feel the power but the turbo only spooled up at 3.5k, and it felt like you'd only just begun to hit to power band and then you had to shift - and next gear you'd drop right out of boost and you'd be a slug again

so i tried driving hard, spinning out to near redline before shifting. on boost it was definitely strong - but then every time you shift, even landing above 3.5k in the next gear, the turbo would drop off and you'd have to wait a second for it to spool before the power came back on

honestly it felt that in every day driving, my Barina would make mincemeat out of this turbo hatch - and i couldn't imagine trying to power out of a corner hard with such an awful power delivery!

to the owners of turbo cars: are they all like this? i'm thinking it was something to do with my driving style, maybe i shift too slowly, and i'm not used to having to keep a car in boost? or is it just that the ralliart colt has bad turbo lag or bad gearing?

it just seemed that if you want any sort of performance, you really have to drive the car hard hard hard - bang the next gear in, keep it above 4k. is this normal? if so i have to say, from my short drive i am definitely more an N/A fan

interested to be educated by comments from SRiT et al owners

No way Lithium, something's wrong or a miss there !!!

I'd say that Colt you drove was mechanically unsound or it wasn't boosting or running properly...

I know for a fact there was a member here (ZC74) think it was who took on a turbo Colt a couple of years ago with his V6 Vecce C over a number of drags one night and got his doors blown off every time !

They are pretty quick little zippers...

But just to satisfy yourself, try and get a test drive of several other types of 4 pot turbo cars before making a final judgement, just rock up to any dealership and go for it...they're not all the same and definitely better, faster, quicker and more fun to drive than a similar N/A 4 pot that's for sure

[lithium]

Is that the AWD version?

Wish my dyno chart went to lower revs - but it was definitely well spooled by 2800rpm - 0.8bar, as low as the dyno goes. Peak boost of 1 bar is at 3600rpm.

Those Magna Sports are underrated cars, good pick .

EDIT: As above! AWD?

i got the front driver - less things to break and easier to get spare parts when they do! i've been a bit burnt from my experiences trying to find SRi Barinas at the wreckers, so this time i am going for a mainstream car

also i believe the AWD magna is a bit porky - the fwd is way way faster. and fwd isn't half as bad as people like to make out

[lithium]

I believe that it would come down to your driving style quite a bit. Driving a N/A and a turbo car is very different. When you say driving hard, was that flat foot?(wide open throttle = WOT) Power delivery is totally different in a turbo charged car. Its hard to explain in words, well for me it is anyways.

Basically when driving a turbo car, you have on boost and off boost. Off boost is vacuum, which means when idling/cruising and driving soft you engine is running on a vacuum = engine sucking in air. The turbo can boost the air pressure to atmospheric pressure and still not be on boost. This allows the engine to have as much or more power than its N/A version and only using a little throttle. When going on boost the turbo forcing air into the engine. This can only really be done under WOT (wide open throttle) you are able to boost a little from atmospheric to about 4psi with out going on full boost.

Your best bet to fully understand this and the power delivery would be jump in a members or friends turbo car. If it has a PSI gauge with vacuum and boost will make it a easier to understand.

My Astra SRi-T has plenty of power low down with max torque (427Nm) at 2250rpm @ 17psi. 1000rpm = 290Nm @ 11psi


Hope that makes sense, probably not tho. Note this is taken from my car and my understanding. If im wrong please feel free to correct me.

yes it makes sense and is what i noticed. when driving hard it was at WOT. i guess i felt that it was sort of 'all or nothing' - there wasn't much power until you were WOT, in the second half of the rev range and the turbo had spooled up! perhaps its just something i'd have to get used to if i buy a turbo car in future

[lithium]

No way Lithium, something's wrong or a miss there !!!

I'd say that Colt you drove was mechanically unsound or it wasn't boosting or running properly...

I know for a fact there was a member here (ZC74) think it was who took on a turbo Colt a couple of years ago with his V6 Vecce C over a number of drags one night and got his doors blown off every time !

They are pretty quick little zippers...

But just to satisfy yourself, try and get a test drive of several other types of 4 pot turbo cars before making a final judgement, just rock up to any dealership and go for it...they're not all the same and definitely better, faster, quicker and more fun to drive than a similar N/A 4 pot that's for sure

hmm, its possible Wraith but the engine did sound pretty healthy. when it was on boost it was definitely strong, and IF you could keep it there, it would certainly blow the doors right off my Barina. i could believe it would do the same for an auto V6 veccie as well.

i guess my main gripe was that it was difficult to keep on boost and drive like that - one gear too high at the wrong time, one gear change too slow, go off WOT and the boost would disappear and you'd have to wait a second or more for the turbo to spool it back up. probably its my driving style but it was a new experience for me i'll take your advice and when its time to replace a car again, i'll give a few more turbo 4 pots a go to see how they are

[Ice]

to the owners of turbo cars: are they all like this? i'm thinking it was something to do with my driving style, maybe i shift too slowly, and i'm not used to having to keep a car in boost? or is it just that the ralliart colt has bad turbo lag or bad gearing?

your welcome to take my 09 CDTi for a test drive. I can gaurantee you wont be dissapointed, Stock it has 320nM

[rjastra]

i got the front driver - less things to break and easier to get spare parts when they do! i've been a bit burnt from my experiences trying to find SRi Barinas at the wreckers, so this time i am going for a mainstream car

You can always add a supercharger to the 3.5L v6

[gman]

Unfortunately it's not that easy to say... 'this is why'

The reason you may have felt that with the Colt, is because it's only a 1.5L. The bigger the engine before the turbo is taken into consideration, the more likely you are have a torquey engine... hence not as much boost required

Of course this is a very general rule... but a case in point would be the XR5 vs Astra Turbo/VXR. The 320nM of torque in an XR5 peaks at 1600rpm, and is almost flat until around 5000rpm. The Astra Turbo however peaks around 4000rpm, so it's somewhat lacking down low. I can vouch for this, as I own one. Now obviously the VXR makes more power than the XR5, but the turbo has to boost harder. This can mean a somewhat non-linear power delivery... torque steer etc etc

Mizled, do you have a source ? Official figure is peak torque of 250Nm available from 1950rpm-5600rpm. Which means the stock map must keep the boost flat from 1950rpm onwards. My map messes it a bit, allowing it to come on harder (1 bar) at 3600rpm.

Having owned both an Sri-T and an XR5 Turbo, I can confirm that torque delivery in the XR5T happens at very low revs (1500 as mentioned) and car pulls very well without reving too much. In the sri-t, it felt a bit sluggish until about 3500rpm.....that could also be because of 320NM vs 250NM and 320 is reached at 1500rpm compared to 250 at 1950rpm in sri-t. Im guessing the VXR would be slightly better. The xr5t is a sweet engine and it sounds really nice when driven hard!

Mizled_SRi-T, I am starting to understand your name a bit more. You really don't seem to like your AH SRi-T too much...Is it really that bad??

The characteristics of an engine are influenced by more than just its capacity and in the case of turbo cars, the boost it runs.

Using the examples given influences include:

The XR5 is a 5 cylinder vs the SRi-T 4 cylinder
The XR5 is 2.5Lt capacity vs 2.0Lt capacity
The XR5 has a slightly higher compression ratio of 9.0:1 vs the SRi-T's 8.8:1
The XR5 runs max boost of 0.65bar vs the SRi-T's maximum of 0.68 bar
The XR5 has a 6 speed vs the SRi-T's 5 speed gearbox

So an XR5 will produce more torque off boost due to higher compression ratio, larger capacity and greater number of cylinders. To do this it uses more fuel also but can use either lower boost and or the same size turbo to reduce lag and get more torque earlier as there are more cylinders driving the same size turbine to the same boost levels.

There is also the tuning and the actual design of the engine, head, cams, engine management, ancillaries etc but that's a whole different story. Also you can have different styles of turbo cars. Low boost efficiency or high boost performance applications. I would prob put both the XR5 and SRi-T in the middle of the road...Semi performance applications.

However, to say the SRi-T is lacking low end torque in stock form I'd have to disagree. For a 2.0Lt turbo its pretty good and I've never had an issue with it. My other cars have more cylinders and bigger engines and in some ways I actually like the SRi-T more...But in relation to the XR5, its simply just that the XR5 has more of almost everything! More cylinders, more capacity, more compression and from what I've read it uses more fuel to do it to...But that's the trade off...Same as a V8 or V6...

As for Japanese turbo cars and lots of lag, it usually the case. But as said you learn to drive around it. The Japanese engineers say it's so you can drive the car normally off boost around town but then have performance only when you need it. Whatever either way, I like'em...

[USC]

AH SRI-T is 6 speed manual. Petrol consumption for AH SRI-T is 9.2/100km and 9.5/100km for a Mondeo XR5(mind you, it is a much larger car). The XR5 seems more economical than the AH SRI-T I had from real life experience.

[mania]

Interesting - does it have EGR? Of course it does depend on how you drive it though.. only review I could really find on fuel consumption for the focus ST said they were seeing 15L/100km. Whilst they were probably driving particularly hard - I really struggle to exceed 13L/100kms =/. Average around 9.5-10L.

EDIT: I kept on looking, and found a few more. Here (between 25-23mpg - 11.3-12.3L/100kms), and here where some owners are seeing 14.2L/100kms

Not too surprising - the engine with 25% increased displacement uses 25% more fuel .