Underdrive

deesun · 10-04-2009, 05:38 PM

Until recently I really didn't know 100% what an underdrive was

: . I did have some idea but not absolutely sure. A few weeks ago Molloy had one for sale at a great price that would fit my BA XR6 so I asked what it was and decided to buy it and have his work fit it. I must say I'm impressed

: . I had SVI LPG fitted about 12 months ago and although all reports say no power loss I felt I had lost some even though I had a zorst and Haltech fitted at the same time. 161kw was shown to me on the graph but it still didn't seem to have that punch it used to

: . I then had it retuned at a very well known tuner in Sydney at considerable expense . Lotsa bucks with no gains and slightly worse fuel economy

: . Back to the original gas place, plug in original gas tune, no power difference but economy has returned.
Now the underdrive, VROOOOOM, the punch has returned only better. The car revs cleaner, faster and at mid range better than ever. I also thought the gear changes before were off, slurring, taking longer to change from 3rd into 4th, auto box. Almost like it wasn't sure if it wanted to or not. Now its definate, no indecisiveness, just changes. A world of difference. I even think the economy is better but as I never ran figures before I can only guess. It has always been very constant in the fuel it uses no matter the driver and you can almost say within a k when on a trip when the last light will come on so the next trip will give me a better idea. All up I think it was great value and even at full price would be too. Thank you Simon.

Molloy · 10-04-2009, 05:50 PM

No worries mate glad 2 here its all gone good after our install

dreadly · 13-04-2009, 08:18 PM

Under drive pulley= harmonic balancer lol, got my herrod motorsport new old stock, arrived last week, still away will fit when i get back. Cant wait ;)

bcr2734 · 13-04-2009, 08:22 PM

Quote:

Originally Posted by deesun

Until recently I really didn't know 100% what an underdrive was

: . I did have some idea but not absolutely sure. A few weeks ago Molloy had one for sale at a great price that would fit my BA XR6 so I asked what it was and decided to buy it and have his work fit it. I must say I'm impressed

: . I had SVI LPG fitted about 12 months ago and although all reports say no power loss I felt I had lost some even though I had a zorst and Haltech fitted at the same time. 161kw was shown to me on the graph but it still didn't seem to have that punch it used to

: . I then had it retuned at a very well known tuner in Sydney at considerable expense . Lotsa bucks with no gains and slightly worse fuel economy

: . Back to the original gas place, plug in original gas tune, no power difference but economy has returned.
Now the underdrive, VROOOOOM, the punch has returned only better. The car revs cleaner, faster and at mid range better than ever. I also thought the gear changes before were off, slurring, taking longer to change from 3rd into 4th, auto box. Almost like it wasn't sure if it wanted to or not. Now its definate, no indecisiveness, just changes. A world of difference. I even think the economy is better but as I never ran figures before I can only guess. It has always been very constant in the fuel it uses no matter the driver and you can almost say within a k when on a trip when the last light will come on so the next trip will give me a better idea. All up I think it was great value and even at full price would be too. Thank you Simon.

so what was this thread about?

deesun · 14-04-2009, 07:20 PM

^^^^^^^^ Simon had asked me to post my impressions for others considering putting one on and to let him know the result.

bcr2734 · 15-04-2009, 10:13 PM

oh ok. hmmmm