[doc] Re: #2727 Twin Turbo Progress

["Christophe Vieira" <chris_delorean@xxxxxxxxxxx>]

Hello Martin,

Really nice job...
Does this engine runs with this exhausts setup ?
Is it not too noisy without silencer ? I know that turbos reduce it
but it must be very loud...

Could you record a little video with a stock car and this one side by
side to compare engine sound differences ?

Best regards,

Chris.


--- In doc-uk@xxxxxxxxxxxxxxx, Martin Gutkowski - DMC Ltd <martin@...>
wrote:
>
> Hi All
> 
> Harking back to a week prior to Eurofest, I posted some photos of my 
> friend Rich's #2727 twin turbo engine that we've been building. Quick 
> synopsis: 2458cc Renault 25 Turbo even fire EFI engine built into 
> DeLorean block with a couple of Alpine GTA bits and an Island twin
turbo 
> kit. We added a pair of intercoolers and just prior to Eurofest, fell 
> foul of a dead turbo (mucho smoko). The project has been on hold while 
> other tasks were cleared following three shows on the trot but in the 
> past week, she's had a couple of donor turbos fitted from Mazda 323's 
> (still the IHI RHB52 but water cooled - chosen for the capacity of the 
> donor engine (1.5 litre) and the factory boost of 9psi). No photos 
> because, frankly, it looks exactly mthe same as the ones I posted back 
> then...
> 
> http://www.delorean.co.uk/DSCN2233.JPG
> http://www.delorean.co.uk/DSCN2234.JPG
> http://www.delorean.co.uk/DSCN2235.JPG
> http://www.delorean.co.uk/DSCN2236.JPG
> http://www.delorean.co.uk/DSCN2237.JPG
> 
> ...but it sure as hell goes better.
> 
> Currently we have the map that was created on the rolling road under 
> normal aspiration, and an ignition map from some other engine set
with a 
> MAP limit of 2 bar (1 bar of boost). The MAP sensor Rich bought for the 
> engine is from a Ford Cosworth and in calibration, we discovered it
will 
> actually measure nearly 20psi of boost despite being a 2 bar sensor (do 
> you like the constantly flicking between bar and PSI? :-) The ecu we're 
> using has an adaptive mode, and with the addition of a bosch wideband 
> lambda sensor, does a remarkable job of writing its own map based
purely 
> on driving the thing.
> 
> We decided to take the car on a 4 mile trip to the nearest petrol 
> station and Rich drove while I watched the ECU outputs like a hawk.
This 
> was on the hottest July day since records began..... on a turbo car 
> running high boost..... yikes. (just shy of 100F). I say Yikes
because I 
> have a live readout of Manifold Air Temperature and as the boost 
> approached 15 psi (1 bar), the ECU was telling me we had air at nearly 
> 80 degrees C entering the engine (176F). I think those intercoolers are 
> going to be moved downwards...
> 
> After a bit of wastegate messing, we got it limiting at first 3psi,
then 
> 8psi, then hitting the ECU's boost limit (set to 200kPa - well the 
> software works in kPa - keep up!) at 5000rpm. Gutless at bottom end,
and 
> obviously in need of a proper tuning session, I am however happy to 
> report that it shows all the signs of being a very quick car. The boost 
> comes in at as low as 1200rpm, and will really benefit from an ECU 
> controlled boost control valve to stop the wastegates opening at all 
> till the target boost is reached - currently it's lovely and
progressive 
> but I'm sure we can gain some torque with more boost lower down in the 
> revs.
> 
> And much as I hate the film, the fast'n'furious dump valve noises
really 
> put a grin on yer face in a DeLorean :-D
> 
> Martin
>






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