Max speed of 4ltr Chim ?
Discussion
tonyrec said:
Just interested to know what indicated top speeds people have had on their 4 ltr Chims on track days.
Had mine checked for accuracy and it was showing 105mph at a true 100mph.
Tony I had 153 on the speedo at mania........
Hopefully thats accurate, But been saying it was 155
tonyrec said:
Dave.....was that flat out?
The reason that i ask is that i had an indicated 170 !
170 I braked too soon,i was looking for the 300/200/100 mtr boards but saw a brake sign so i ........
then saw the boards down a bit I dont think i would of got a lot more tho, maybe a couple of mph
I'm fairly sure they should crack 160 given the right road...obviously aerodynamics will impact on v-max but just look at it: lightweight construction and circa 250 bhp from a 4.0 V8 - it HAS to do at least this!
Try France, the Massiv Central and a firmly planted right foot...pas de problem!
Try France, the Massiv Central and a firmly planted right foot...pas de problem!
Had 138 in mine at the runway at Mania last year. Started to pull the dust and crap off the floor (cos I had the roof off) and hence chickened out. To be honest I doubt there was much left in it - maybe another 5 - 10 MPH, but you would need a damn straight road to get that extra bit.....
Roof on and with good conditions I think that the max would be around the 150 mark. Mines DEAD accurate on the speed (GPS checked - well, OK fairly accurate!!) and at those speeds you would run out of road before hitting them....
Suspect the 170 is over-reading. For example a Tuscan S on the same Mania run managed 160 and had one gear left (red line on 4th). He was running out of runway and thats a 390BHP monster that is just soooo much faster than a 500 and especially a 400....
Roof on and with good conditions I think that the max would be around the 150 mark. Mines DEAD accurate on the speed (GPS checked - well, OK fairly accurate!!) and at those speeds you would run out of road before hitting them....
Suspect the 170 is over-reading. For example a Tuscan S on the same Mania run managed 160 and had one gear left (red line on 4th). He was running out of runway and thats a 390BHP monster that is just soooo much faster than a 500 and especially a 400....
[quote=pbrettle]Had 138 in mine at the runway at Mania last year. Started to pull the dust and crap off the floor (cos I had the roof off) and hence chickened out. To be honest I doubt there was much left in it - maybe another 5 - 10 MPH, but you would need a damn straight road to get that extra bit.....
Roof on and with good conditions I think that the max would be around the 150 mark. Mines DEAD accurate on the speed (GPS checked - well, OK fairly accurate!!) and at those speeds you would run out of road before hitting them....
Totally agree...
I did 2 runs at Mania with the roof off and one passenger in a 95 4.0 that had just been serviced and made 140 & 145 - I reckon it would have another 5-10 left in it/roof on? I have no idea on the accuracy of the speedo but it it SEEMS OK.
Roof on and with good conditions I think that the max would be around the 150 mark. Mines DEAD accurate on the speed (GPS checked - well, OK fairly accurate!!) and at those speeds you would run out of road before hitting them....
Totally agree...
I did 2 runs at Mania with the roof off and one passenger in a 95 4.0 that had just been serviced and made 140 & 145 - I reckon it would have another 5-10 left in it/roof on? I have no idea on the accuracy of the speedo but it it SEEMS OK.
I was lucky enough to get a passenger ride in the TMS racing Griff 500. It is running a standard engine with a genuine 300bhp and we saw a genuine 159mph on the runway. It got there pretty quick and held it for about 1 mile. I am not sure whether the gearbox or diff have been altered but this seems in line with the TVR claim of 161 for a 500. I would not expect a 4litre Griff/Chim to exceed about 150.
Its all academic really but the whole point of this posting was just to highlight the point of potential top speeds being a hell of a lot different between even a few 4ltr Chims.
Some have said that their cars showed an indicated 138-143..hmmm...i would be asking questions as to why a 4ltr lightweight car with a manufacturers claimed max speed of anywhere between 152-156mph was only capable of pulling about 135 true speed taking into account the overeading on the speedo.
Iam quite satisfied that i was travelling extremely fast, in fact faster than i had travelled before but what i cant comment on is how accurate my speedo was between the tested 105mph and the indicated 170.
At this indicated speed i would have expected the car to have been travelling at certainly over 150 but between 155 and 160mph, which incidently is around the figures set by TVR.
Some have said that their cars showed an indicated 138-143..hmmm...i would be asking questions as to why a 4ltr lightweight car with a manufacturers claimed max speed of anywhere between 152-156mph was only capable of pulling about 135 true speed taking into account the overeading on the speedo.
Iam quite satisfied that i was travelling extremely fast, in fact faster than i had travelled before but what i cant comment on is how accurate my speedo was between the tested 105mph and the indicated 170.
At this indicated speed i would have expected the car to have been travelling at certainly over 150 but between 155 and 160mph, which incidently is around the figures set by TVR.
tonyrec said:
Its all academic really but the whole point of this posting was just to highlight the point of potential top speeds being a hell of a lot different between even a few 4ltr Chims.
Some have said that their cars showed an indicated 138-143..hmmm...i would be asking questions as to why a 4ltr lightweight car with a manufacturers claimed max speed of anywhere between 152-156mph was only capable of pulling about 135 true speed taking into account the overeading on the speedo.
Iam quite satisfied that i was travelling extremely fast, in fact faster than i had travelled before but what i cant comment on is how accurate my speedo was between the tested 105mph and the indicated 170.
At this indicated speed i would have expected the car to have been travelling at certainly over 150 but between 155 and 160mph, which incidently is around the figures set by TVR.
You need horsepower for high speed. Put a dozen Chimaeras on the same rolling road and you'll get 13 different power readings.
I know of a 4.0HC that made the same power as my std 4.0 before it was fettled - same RR, same morning (fettling took mine up from 209hp and 228lb ft to 241hp and 245lb ft - thanks to a Mark Adams chip, megnecors, new coil and injectors cleaned/replaced).
My 4.0L Chimaera has been up to 155 (French Autoroute), but that was a few years ago before I had it tuned properly. Mind you, it wasn't 'flat out' - I didn't keep my foot to the floor until the car stopped getting faster. I guess it would do a tiny bit more now. My speedo is reasonably accurate, but I've never tested it's accuracy above 100mph so allowing for a bit of error 155-160 seem perfectly obtainable from a 4.0 making the quoted horsepower figures.
Tony - maybe yours overreads a tiny amount, but I guess a 4,0HC in good fettle would do a few more mph than a std 4.0L. 170 is a bit much though
Good for the pub though.
I've had mine showing an indicated 165mph @ 5600rpm (although it could be a few more revs than that, as I didn't want to take my eyes off the road too long) My limiter cuts in at 5800rpm.
As a reference, I know my speedo (when checked against a garmin GPS) at 80mph is actually only doing 73mph. So if the inaccuracy continues at the same percentage all the way up, 165mph (indicated) was a true 150mph.
jj
As a reference, I know my speedo (when checked against a garmin GPS) at 80mph is actually only doing 73mph. So if the inaccuracy continues at the same percentage all the way up, 165mph (indicated) was a true 150mph.
jj
Deristrictor said - --------------------------------------------------------------------------------
I'm fairly sure they should crack 160 given the right road...obviously aerodynamics will impact on v-max but just look at it: lightweight construction and circa 250 bhp from a 4.0 V8 - it HAS to do at least this!
Try France, the Massiv Central and a firmly planted right foot...pas de problem!
-------------------------------------------
No 4.0 std will ever put out 250 crank brake HP (210 if lucky) - aerodynamic on Chimera aren't that good,
and seem fairly short geared. I doubt a 500 has ever pulled much more than 160 true mph and would be over the power peak so having trouble staying there. 4.0 about 150 on a long run if lucky (roof up of course)...
I'm fairly sure they should crack 160 given the right road...obviously aerodynamics will impact on v-max but just look at it: lightweight construction and circa 250 bhp from a 4.0 V8 - it HAS to do at least this!
Try France, the Massiv Central and a firmly planted right foot...pas de problem!
-------------------------------------------
No 4.0 std will ever put out 250 crank brake HP (210 if lucky) - aerodynamic on Chimera aren't that good,
and seem fairly short geared. I doubt a 500 has ever pulled much more than 160 true mph and would be over the power peak so having trouble staying there. 4.0 about 150 on a long run if lucky (roof up of course)...
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