I have been in talks with Josh@Severn Tuning https://www.severntuning.com/ since the end of January about getting a tune done for the Z4 after the previous tune I had done left me with a very rich running and at some points in the rev range a not very happy car . The dyno figures looked ok but I just wasn`t convinced they had done everything they could have done as the software program was not working properly . They also only did 3 tunes and that was that .
Josh was a breath of fresh air . He wanted to spend some more time on the N52 engine and I wanted to get the best out of it with my set up so we agreed to spend longer than normal to get it right . Josh had to start by finding a way to unlock the ECU as it had been locked by the previous tuner . He then had to start from the basic stock file and build it up tune by tune . I used his software to datalog the drives around my local roads and then he would work on that data and email me another tune clearing any codes that were produced on the way .The first tune was done on the 7th March and the final tune before dyno which was number 10 came through on April 18th . I was using the same set of roads for the last 7 of these tunes so that it was consistent and I could feel the difference in acceleration . I was running out of road much quicker :evil:
The next step was to arrange a dyno day to do the Vanos tuning which you wouldn`t think would be a problem but Josh is in Hawaii which is currently 11 hours behind the UK . I spoke to my Dyno man Graham and he said he couldn`t start before 8am or go beyond 6pm as there are some houses not far away . This meant that we arranged to start at 8 am on Tuesday 14th May which was 9pm Monday 13th May in Hawaii .
Unfortunately I was held up on the way to Graham which is about an 1hr 15 mins away from me due to slow lorries down winding lanes and a BMW that looked like it had done a 360 on the A55 and was smashed into some trees . Police were there but no ambulance so hopefully they were ok . I turned up at 7.30 and by the time Graham had set everything up it was nearer 9am but Josh took it all in his stride .
We were supposed to be doing a 3 hour session but we ended up doing 12 tunes on the dyno sending logs and graphs to Josh and him sending the tune back .
We finally finished at 12.45 UK time which was 1.45 am in Hawaii !!
Josh said that the high end was almost dialed in already from the road logging we had done but the Exhaust Vanos tuning is where he got most gains in the mid range .
Josh has got as much as you are going to get out of this N52 engine without changing the inlet manifold or possibly cams. Vanos is Maxed out .
Points to note though are that this is an auto box so will probably get more from a manual and you may see higher numbers elsewhere but all Dyno`s are not equal . From a driving point of view its more than enough power for me and it is in the right place .
I`ve got to say that I would definitely agree with all the excellent comments I have seen praising Josh@Severn Tuning he was very informative about what was happening throughout and nothing seemed too much bother . His forum name is [ref]pokeybritches[/ref],
Graham the Dyno man works from Holywell in Flintshire if anyone wants to use his Hub Dyno for a fee of course . He doesn`t tune BMW ECU`s but does work with Syvecs if you wanted a stand alone ECU to go racing .
All dyno runs were done in fourth gear only and are recorded as wheel horse power not brake horse power .
On the graphs please take into account T10 has a high humidity level so probably best to take T11 and compare it to T22 . Unfortunately I didn`t notice at the time otherwise I would have asked for a T11 and T22 graph comparison . T15 unfortunately doesn`t show on the table at the bottom .
Sorry PDF `s don`t attach so I screen printed them into paint and they are not very clear .
Tune 11 was WHP 199.16 @ 5870 RPM and Wheel Torque 211.66 @ 4493 RPM which is low as this is how Josh works out the correct tune for Vanos
Tune 22 Final tune was WHP 235.05@ 5880 RPM and Wheel Torque 228.97 lb/ft @ 3734 RPM
[youtube]Lt4I2gWFcTY[/youtube]
Round here I would have to be blacking them up every time I went out . We are surrounded by farms dropping cow manure and mud all over the roads . I suppose I could have done for the photos if I had any