Evo 400bhp hatch test.
Discussion
Flicked through this in tesco, may buy it later. They had a test of jumped up versions of the Astra vxr, focus st, golf gti and audi s3. All had different turbos and other work done to them. Both the golf and audi had the same turbo (garret t28 I think?). Anyway they rolling roaded all but the focus and I was staggered at the results - not how impressive they were but how awful and what a great demonstration of what is lost in creating a big power engine.
At first It seemed that peak torque was all approx 4500-5000rpm, and Astra was highest while Audi was significantly the lowest. Peak power on most was in the 5000-6000 region, except the Audi where it was at ~7000, hard to tell because it was a bit of a mock up graph. From all this you'd think the Astra was strongest and the Audi a bit flat.
However it was in fact a great demonstration of how figures don't tell the story and it should be about area under the curve. Most of them, even the Golf, had absolutely nothing below 4000rpm and just peaked with staggeringly high power and torque figures all between 4000 and 6000. The Audi on the other hand had about twice the torque of the others right from 2000 revs up, just peaking at a rather lower figure of ~330 lbft against over 400 for the Astra. But despite rather boring sounding peak figures recorded at similar or higher RPMs, the truth was no apparent with seeing the exceptional torque curve. The others all looked like smart 800cc engines in comparison, even the Golf which should be the same basic engine but obviously was not set up anything like as well?
The Audi demonstrated its (4wd) excellence with a 4.3 second 0-60 run and 0-100 not far off 10 seconds...
At first It seemed that peak torque was all approx 4500-5000rpm, and Astra was highest while Audi was significantly the lowest. Peak power on most was in the 5000-6000 region, except the Audi where it was at ~7000, hard to tell because it was a bit of a mock up graph. From all this you'd think the Astra was strongest and the Audi a bit flat.
However it was in fact a great demonstration of how figures don't tell the story and it should be about area under the curve. Most of them, even the Golf, had absolutely nothing below 4000rpm and just peaked with staggeringly high power and torque figures all between 4000 and 6000. The Audi on the other hand had about twice the torque of the others right from 2000 revs up, just peaking at a rather lower figure of ~330 lbft against over 400 for the Astra. But despite rather boring sounding peak figures recorded at similar or higher RPMs, the truth was no apparent with seeing the exceptional torque curve. The others all looked like smart 800cc engines in comparison, even the Golf which should be the same basic engine but obviously was not set up anything like as well?
The Audi demonstrated its (4wd) excellence with a 4.3 second 0-60 run and 0-100 not far off 10 seconds...
it all depends on what you are doing with the cars/engines. if you dont mind reving the nuts of the engines all the time its not a problem. however on the road this could be very boring/require a change of driving style to make the bost out of it.
also who was doing the work? what else was done (apart form the bigger turbos)? this can have a massive effect on the way a car drives and when peak boost is achived.
also dont always knock these higher power xcars. sometimes when you look closely at the graphs you miss that they are actually making massive power down low but the graph makes it LOOK like they aren't.
finally, there is always an aftermarket ECU and anti-lag to help out!
Chris.
also who was doing the work? what else was done (apart form the bigger turbos)? this can have a massive effect on the way a car drives and when peak boost is achived.
also dont always knock these higher power xcars. sometimes when you look closely at the graphs you miss that they are actually making massive power down low but the graph makes it LOOK like they aren't.
finally, there is always an aftermarket ECU and anti-lag to help out!
Chris.
chuntington101 said:
it all depends on what you are doing with the cars/engines. if you dont mind reving the nuts of the engines all the time its not a problem. however on the road this could be very boring/require a change of driving style to make the bost out of it.
also who was doing the work? what else was done (apart form the bigger turbos)? this can have a massive effect on the way a car drives and when peak boost is achived.
also dont always knock these higher power xcars. sometimes when you look closely at the graphs you miss that they are actually making massive power down low but the graph makes it LOOK like they aren't.
finally, there is always an aftermarket ECU and anti-lag to help out!
Chris.
That's true but I'm guessing (key word) they're already drinking fuel without anti-lag! Does anti-lag kill exhausts too?also who was doing the work? what else was done (apart form the bigger turbos)? this can have a massive effect on the way a car drives and when peak boost is achived.
also dont always knock these higher power xcars. sometimes when you look closely at the graphs you miss that they are actually making massive power down low but the graph makes it LOOK like they aren't.
finally, there is always an aftermarket ECU and anti-lag to help out!
Chris.
The points you raised are all the ones that are relevant really aren't they - who is doing the work and how. Thought it was a good demo though of how some companies really know what they're doing. The conversion on the S3 was £5000 which didn't sound too bad.
Pentoman said:
chuntington101 said:
it all depends on what you are doing with the cars/engines. if you dont mind reving the nuts of the engines all the time its not a problem. however on the road this could be very boring/require a change of driving style to make the bost out of it.
also who was doing the work? what else was done (apart form the bigger turbos)? this can have a massive effect on the way a car drives and when peak boost is achived.
also dont always knock these higher power xcars. sometimes when you look closely at the graphs you miss that they are actually making massive power down low but the graph makes it LOOK like they aren't.
finally, there is always an aftermarket ECU and anti-lag to help out!
Chris.
That's true but I'm guessing (key word) they're already drinking fuel without anti-lag! Does anti-lag kill exhausts too?also who was doing the work? what else was done (apart form the bigger turbos)? this can have a massive effect on the way a car drives and when peak boost is achived.
also dont always knock these higher power xcars. sometimes when you look closely at the graphs you miss that they are actually making massive power down low but the graph makes it LOOK like they aren't.
finally, there is always an aftermarket ECU and anti-lag to help out!
Chris.
The points you raised are all the ones that are relevant really aren't they - who is doing the work and how. Thought it was a good demo though of how some companies really know what they're doing. The conversion on the S3 was £5000 which didn't sound too bad.
anti lag is harder on the trubo(s) its self. however modern turbos are MUCH better at taking the higher temps and presures. Plus alot of systems are switchable so you can turn down how hard the Anit-lag hits.
there are other things you can do aswell. one thing just starting to take off in the US is a quick spool valve. this can be used on a open scroll style turbo manifold but requires a divied housing (or twin scroll) turbo to be used. basically you maount a sandwhich plate between the mani and turbo. this plate thas a butterfly style valve that blocks one side of the twin scroll turbo (ie blocks one of the holes). this halfs the AR of the turbo. now this reduction of AR results in faster responce/reduced spool up time. hioowever if you left the valve closed it would cause massive backpresure and choke the engine at higher RPM. so once a set boost presure is reached the valve will start to open (the simplist method of doing this is to use a actuator like what is used in internaly gated turbos). once the valve is fully open the turbo will operate as it would do normally, so you still get the same BIG top end power numbers. but thanks to the vavle you get faster spool up low down the RPM band.
now using the above vavle means you can run a bigger turbo and get the same spool up as a smaller turbo but with more top end.
if anyone want i can post a link to a thread where a guys has used one of these valves on a rear mounted turboed LS3. worked great for him as he saw a 33% reduction in spool up. by the way these figures where data logged pulls down with abnd without the valve fitted.
cheers
Chris.
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