500 Acceleration
Discussion
Had a Chim 500 for over a year now, and been very, very pleased with it.. However, not sure if just a fact of being used to it, but acceleration does seem a bit flat low down. Theres plenty of torque there, particulary from 50mph onwards, but at no stage are you 'thrown' into your seat.. from memories of test driving a 4.0L it did seem a lot more nippy through the gears.. is this just the nature of the 5.0L?, or would it benefit from a different Cam set etc.?? What would be a realistic 0-60 time? (timing has retarded due to pinking). Or is it just me!!
I've just been running around in a 2.7 Boxster whilst my 400 chim was in for some bodywork. My TVR is faster than the boxster but it's very progressive. In the Porsche I felt nothing until hitting 6-8000 Rpm when I actually felt like I was being pushed back into the seat, something I never feel in the TVR. I think it's because of the TVRs constant steady power rather than a boost only over 'x' Rpm.
Getting used to the car as well is a big consideration. When I first got the Chim it felt sooo fast, now it just feels normal and I often yearn for more despite having ample at the moment.
Getting used to the car as well is a big consideration. When I first got the Chim it felt sooo fast, now it just feels normal and I often yearn for more despite having ample at the moment.
Try adjusting the timing back as it should be for a start. Then, put a pin hole in the plastic pipe from the vac advance unit on the dizzy.... This will reduce the timing advance on hard acceleration and hopefully in the pinking..if it reduces it but doesn`t stop it, enlarge the hole.....
I had exactly the same feeling - felt as if my Griff lost it's zing.
That was untill a R32 stuck his nose up the Griff's backside with flashing headlights - dropped a cog and blew him into the weeds....no, it was not remotely a contest.
Oh yes, and then there was a 996......same
The zing is still there
That was untill a R32 stuck his nose up the Griff's backside with flashing headlights - dropped a cog and blew him into the weeds....no, it was not remotely a contest.
Oh yes, and then there was a 996......same
The zing is still there
Thanks for the replies.. Had a couple of services now.. does retarding the timing make much a big difference?? Heard two different reports.. one saying that the power drops of pretty quickly when retarded, the other saying that it makes little, or no difference..? At the time when it was retarded was using lower octane fuel so was thinking of adjusting this myself as noted above... is this easy to do?, does anything else need to be done in parallel? Idiots guide would be appreciated!
) for a week or so. 
...Mad Mitch said:
Try adjusting the timing back as it should be for a start. Then, put a pin hole in the plastic pipe from the vac advance unit on the dizzy.... This will reduce the timing advance on hard acceleration and hopefully in the pinking..if it reduces it but doesn`t stop it, enlarge the hole.....
WTF?
Mad Mitch said:
Try adjusting the timing back as it should be for a start. Then, put a pin hole in the plastic pipe from the vac advance unit on the dizzy.... This will reduce the timing advance on hard acceleration and hopefully in the pinking..if it reduces it but doesn`t stop it, enlarge the hole.....
???
That seriously can't be good, when I've had vacuum leaks in any cars I've worked on it has always caused bad problems. I can't see how puropsefully inducing a leak will benefit the car. When I had problems I had the advance curve reprofiled. Retarding the timing will definitely affect the performance.
I'd have the car put back to the stock settings and run it on 98 RON.
GreenV8..... Vac pipe mod worked perfectly well on Vauxhalls suffering from pinking and such when unleaded was introduced. Even with the timing retarded as factory mod they could pink under hard acceleration. If the vac unit advances timing enough to cause it to pink why not just reduce the suction to it therefore reducing amount of advance. Worth a try and easily reversible..... If i am wrong then something strange was happening to cars with this carried out in around 1982-90.
Mad Mitch said:
GreenV8..... Vac pipe mod worked perfectly well on Vauxhalls suffering from pinking and such when unleaded was introduced. Even with the timing retarded as factory mod they could pink under hard acceleration. If the vac unit advances timing enough to cause it to pink why not just reduce the suction to it therefore reducing amount of advance. Worth a try and easily reversible..... If i am wrong then something strange was happening to cars with this carried out in around 1982-90.
Um, under full load there's no vacuum and no vacuum advance, so I don't follow the logic. The only problem this could fix is if the vacuum advance line was blocked (perhaps a faulty delay valve), and it seems like a very crude fix to that sort of problem.
zippee said:
I think it's because of the TVRs constant steady power rather than a boost only over 'x' Rpm.
Might I recommend a little test.
Take her on a nice straight dry road, 3rd gear, and hold 3000 rpms for a few seconds, then floor the throttle.. She will thunder like a train and push you back in your seat.
Caveat, this works for the 400, but not the 500 IME.
jasandjules said:
[quote=zippee]
Take her on a nice straight dry road, 3rd gear, and hold 3000 rpms for a few seconds, then floor the throttle.. She will thunder like a train and push you back in your seat.
Take her on a nice straight dry road, 3rd gear, and hold 3000 rpms for a few seconds, then floor the throttle.. She will thunder like a train and push you back in your seat.
Reminds me of a quote I once heard.
"In any gear, at any speed, the TVR leaves the opposition standing in a wall of noise in it's relentless pursuit to headbutt the horizon"
Still say that to myself when I do just what jasandjules said above
I love taking passengers out for a spin. 
2nd gear, steadily up to about 2500rpm, not to give the game away...
Ask them above the hum of the engine, "So, what do you think?".
"Not bad", they say, thinking it is quite noisy and moderately fast.
Then say "Ready?".
A puzzled look on their face. "For what?"
"This!", as you squeeze the throttle, taking it to 6000rpm before changing up.
Stunned silence. Then big silly grins.
2nd gear, steadily up to about 2500rpm, not to give the game away...
Ask them above the hum of the engine, "So, what do you think?".
"Not bad", they say, thinking it is quite noisy and moderately fast.
Then say "Ready?".
A puzzled look on their face. "For what?"
"This!", as you squeeze the throttle, taking it to 6000rpm before changing up.
Stunned silence. Then big silly grins.
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