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After over a year of development of the H Pro T4 and T4E ecu's for the mechanical throttle Lotus Elise and Exige and the electronic throttle T4E version for Elise, Exige and 2 Eleven, we have produced three effective aspirated conversions for these sports cars. The first two conversions are without any kind of internal engine modification and the third involves the replacement of the two engine camshafts.
It is important to note that reflashed ecu conversions for these vehicles seem to perform very badly even compared with the standard factory map. There is a big belief that switching the cams over earlier increases power, (ie VVL effect switchover point). This could not be further from the truth on aspirated 2ZZ engines. When the VVL is engaged at 5700 rpm the effect is absolutely awful with a huge drop in power between 5700 and 6200 rpm. We call this the "driving deaf syndrome", if I explain this as simply as possible. When driving the 2ZZ engine the driver hears a huge engine note change which sounds very agressive compared to the first cam induction note. The additional noise immediately gives the driver the impression that he has suddenly been delivered his horsepower. On the race circuit we proved this point at a test at Snetterton race circuit. We asked our pro driver to lap as quickly as possible for five laps with 5700 rpm switchover, his laptimes where all within 3/10's of a second of each other. We then swiched over to 6200 rpm switchover and immediately the car was 8/10's of a second quicker per lap again with 5 laps completed. In conclusion, the temptation is to have an earlier switchover because your mind believes the car feels quicker but the truth is that the car is significantly quicker when the power is optimised using the correct switchover point.
Lotus aspirated ecu & tuning packages
Stage 1 213BHP
We have been asked many times to provide a replacement ecu for the Lotus Elise, Exige and 2 Eleven.We therefore decided to take a standard car which only had a replacement air box system but still had a completely standard engine and exhaust system. The replacement air filtration system may have contributed a small amount of power. The graph on the right hand side shows the before and after power figures of a completely standard run being lower HP curve and torque curve and the upper curves for HP and torque being the
H Pro ecu with the additional Elise Racing wide band kit fitted. The standard car produced exactly 193 flywheel BHP which equates almost perfectly to the factory power figures, as you can see from the graph, with the H Pro fitted and cam angle map optimised the car produces more power throughout the whole range with over 20 BHP at some points and a respectful 25 wheel BHP in certain area's.
H Pro Ecu £2095
Wide band lambda kit £193
Cone air filter system £287
Stage 2 219BHP
This conversion involves the fitting of one of Jim Valentines 2ubular exhaust manifolds, catalytic converter and silencer systems. With careful mapping the dip at 4500 rpm is removed and the car goes on to produce increased BHP at 7300 rpm as well as the power curve remaining flat up to the rev limit.
Contact us for a quotation for the 2ubular exhaust system.
Stage 3 224 BHP with massive increase to pre VVL mid range torque
The stage 3 conversion uses the 2ubular exhaust package fitted in stage 2 but also includes a pair of uprated Elise Racing specification Piper camshafts. The power increses are immedately present from 2700 rpm onwards with a nice flat torque curve between 2700 rpm and 6000 rpm. The standard camshafts initial pre VVL profile makes it's maximum torque at 4000 rpm due to the very low duration of the camshaft. With the new cam profiles torque is far higher and the driving rewards are excellent.