Standing start acceleration lag

I've had my ecu remapped some 2 years now by TME on my '98 V70 'R' AWD AUTO. While I am extremley pleased with the performance in mid range, acceleration and top end speed, it has only recently been brought to my attention that on initial take up from stand still, there is a lag in take off, O-K, with AWD I am not expecting the tyres to light up, but for the first 40/50 yards its not throw you back in the seat stuff. I understand that on the standard ECU,Volvo deliberatley set this into the computer to avoid wheelspin but I would have thought that this was over written on remap. ,I would appreciate feed back from other auto owners with TME, Rica or similar chipping for their comments.
Thanks
Dave

[burchi]

Hi Dave

I think that the initial acceleration issue all boils down to turbo lag and that is what we have got whether in manual or auto flavour. I have had my V70 R AWD mapped with the RICA software and it is absolutely great. I looked at this and the TME map and the RICA is a little more agressive but still totally driveable. I also know that some owners on this forum have added a larger 19T turbo in favour of the stock 18T but this has more benefit in the higher rev range.

I think that it is the characteristic of a turbo engine that it takes a short while to get going but, when it does.......HANG ON!!!!!!!

Not much help I don't think but, that's the long and short of it!

Regards

[Peter Milnes]

Yes the turbo does cause this sort of behaviour. It is less noticeable on the LPT versions and with a smaller turbo as the spool-up occurs more readily with these versions. The modern variable vane turbos have an excellent spool-up response and would be well worth considering as a replacement to give that little bit more ooomph from standstill. Manual gearbox users can cheat a little by raising the engines rpm and slipping the clutch initially till movement enables full clutch engagement. If your transmission is strong enough you might be able to drop the clutc with about 2,500 rpm or even 3,000 rpm (and leaving a trail of tyre smoke) a la dragster.

All the best, Peter

Thanks for your feed back both Ian & Peter. Knowing that you Ian, live not to far away, and we have threatened to meet up sometime, sooner rather than later may be a good idea to compare performance of the 2 re-map systems, is your's an auto?

Hear from you
Dave

Dave,

I think the problem that you are experiencing is unique to the 4-speed automatic R AWD's. From the factory they were engineered with a reduced torque output (310nm / 0-60 8.1 secs) purely to save the transmission.

TME's up-grade for the 97/98 cars was programmed to give approx 370nm upto 4500 RPM when the torque increases to 410nm, as they had experienced transmission problems with cars where the full 410nm was available at 2400 RPM. They also advise against towing heavy trailers / using high torque at low revs as this can overheat the standard torque converter. A special up-rated torque converter is alledgedly available from the factory.

The RICA chip is more aggressive, but at what cost to your transmission ? The TME up-grade is probably the best compromise of power and longevity for the auto R AWD's.

Neil.

[burchi]

Hi Dave

Mine is a manual variant. We should arrange to meet up. I shall give you a call this week (I've got your number from our previous discussions on the TME exhaust) and we'll arrange so that we can compare!

All the best

Yes, thanks again for that Neil, guess I won't get to bothered about that little bit of lag. Await your call Ian.
Dave