Steve Cragg Posted April 22, 2003 Share Posted April 22, 2003 Just had my 98 superlight on the rolling road for the first time. Power peaked at 134 bhp at 7250 rpm, torque peaked at 110 lbft. The torque curve reaches maximum at approx 3200 rpm and then dips in a "U" shape bottoming out at approx 100 lbft at just over 4000 revs then gets back up to the maximum at 5000 revs. Is this normal? If not, any suggestions on possible causes and how to remedy. Any advice gratefully received. Steve Link to comment Share on other sites More sharing options...
robmar Posted April 22, 2003 Share Posted April 22, 2003 on my old 1.6supersport I had something similar when it was RR'd plots here whether this is normal or not I don't know rob Link to comment Share on other sites More sharing options...
simon_h Posted April 22, 2003 Share Posted April 22, 2003 Thats a normal characteristic for a 4 cylinder engine. Its a function of the short exhaust primaries. If you were to fit a longer 4-2-1 manifold it would be smoothed out a lot, it may not go completely. I've run a lot of K's on dynos and you always get it with the standard manfolds. Link to comment Share on other sites More sharing options...
Steve Cragg Posted April 23, 2003 Author Share Posted April 23, 2003 Thanks guys. Rob's curve is almost identical to mine so guess I can stop worrying. Just need to save up for the 4-2-1 to squeeze a bit more out Steve Link to comment Share on other sites More sharing options...
robmar Posted April 23, 2003 Share Posted April 23, 2003 just to confirm mine was with the cack 4-1 collector inside the engine bay rob Link to comment Share on other sites More sharing options...
old captain slow Posted April 23, 2003 Share Posted April 23, 2003 After fitting the 4:1 the difference in oomph was very noticeable. Not convinced you would gain much with 4:2:1 on a 1600 bog std SS. 😬 Castle Combe Monday Yeeha! C7 CDW Link to comment Share on other sites More sharing options...
Steve Cragg Posted April 23, 2003 Author Share Posted April 23, 2003 My car has the standard superlight 4-1 competition exhaust with primaries that join externally. Would a 4-2-1 and a different silncer make much difference to power/torque characteristics? ISTR seeing a thread where people were saying that changing manifold/silencer from the standard set up had made a big difference in mid range torque. Steve Link to comment Share on other sites More sharing options...
reAnimate Posted April 23, 2003 Share Posted April 23, 2003 Are you running with a MEMs? I think something like a properly mapped Emerald would get rid of most of the dip, there are much more radical K's without this dip. Simon. Link to comment Share on other sites More sharing options...
Steve Cragg Posted April 23, 2003 Author Share Posted April 23, 2003 Its fitted with the standard ECU 2 I believe which as far as I'm aware can't be re-programmed. Steve Link to comment Share on other sites More sharing options...
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