The good old days ?

If you need a suppressor, do it properly and fit one to the alternator or behind the radio.

I was not going to comment on this misleading quote originally as, although partially correct because fitting supressors to Alternators is a must to reduce whine, but because the further quote below is only leading to more confusion and misleading comment.
The fitting of a suppressor behind a radio will have no effect at all from spark induced Interference from commutators in DC electric motors, be it the fuel pumps or other motor operated devices. Any Car Radio worth its salt has its own ferrite supperssion circuit within itself, the Philips OE Radio is no exception. Apart from the ferrite component there is capacitive and inductive components which all work together to eliminate intrusion of interference through the Before and After ign 12v feeds.
It must be remembered that 99.9% of interference on any radio, but car radios in particular, gets into the radio through the Aerial, a particular component that cannot be suppressed except by inefficient band pass filters depending on which frequency band you are tuned to.
So the moral of this is:- In the event of interference, find the suppress at source.

This was followed up by:-

If you get whining through your stereo on 'some occasions' then its not the fuel pump is it, it runs all the time.

In reference to the fuel pump suppression, someone stated that without the suppressor interference was apparent "Intermittently", or as stated above on "some occasions".
I have no problem of understanding the intermittentcy of interference from the unsuppresses fuel pump, because as rightly stated, the pump runs all the time, but that has little to do with it.
What the Intermittent side has to do with, is the "Signal to Noise" ratio. All radios .... especially Car Radios .... have what is called an AVC circuit (Automatic Volume control) the purpose of which, especially radio's on the move, is to keep adjusting the volume of the radio constant while the signal level is changing.
In open spaces the signal to noise ratio (s/n) is good assuming you are within reasonable range of the Radio Station's transmitter, and as such with a s/n of, say, 90% signal, and 10% noise, you will not hear things like the fuel pump, however if you are a long way from the transmitter, in a tunnel or in a built up area, then the s/n can be adversely different, ie:- 10% signal, and 90% noise. Now the AVC is working hard to maintain a user set volume to the listener, but with a changing s/n, the interference part of the audio can apear to come and go ..... Intermittently.
I hope some of you concerned about suppression in their Alps find this interesting and perhaps in reading this, helps you to understand the vagaries of Radio Reception and suppression.

John

I took a customers A610 for a power run a week or so ago to Track and Road, the dyno I use for all my work. Made ok power as expected but got very rich at the top end. Its in for a full chassis resto and some performance tweaks.

As you can see it made 238hp and 251lb/ft at the flywheel at 11psi. Compare that to the twin turbo setup in Dave Miles car 308hp and 302lb/ft at 13psi. They are essentially the same completely stock engines with different ancillaries. The aim for this A610 is to get a reliable and effortless 300hp without increasing boost pressures beyond 15psi.

John, that will explain why they all went backwards at croix then haha.

Cheers for that.
I was however chatting to Tim with the blue 610 at Prescott and he reckons his is running 320bhp as standard. He has however removed some weight. He always sets a blistering time too. Car looked immaculate . (Hope his name was Tim) really nice guy.

Dave, what the f**k are you talking about, once again?

Ive never sold injectors
...
The only injectors Ive ever sold are high end RC Engineering ones ( http://www.rceng.com ) which you've certainly never bought off of me as they are near £100 a piece

Dave, I had a set of six 450cc injectors off you back in 2007 for £195 together with an adaptronic, chargecooler and turbo. Emails to prove.

Pretty sure Dave got his around the same time as I have email correspondance with him shortly afterwards ref Adaptronics.

Cheers for that.
I was however chatting to Tim with the blue 610 at Prescott and he reckons his is running 320bhp as standard. He has however removed some weight. He always sets a blistering time too. Car looked immaculate . (Hope his name was Tim) really nice guy.

Yep that was Tim Jeffrey's car Dave. I was chatting to him and I think he said 300+ but he's running about 18psi of boost, and made some tweaks with the oil re-breather to avoid oil vapour being ingested (hence lower chance of detonation). I think from memory he has an integrated chargecooler under the rear grill (much like Tony's black GTA) - I think that's correct, shame he's not on here. But yes turbo is standard and I don't think he's had any head work done. Lot of boost and some well engineered minor changes.

It's a very well sorted car as you say. Did you catch what make of dampers he was running? I think they cost a few pennies....

Tim's a good bloke who's been on the Alpine scene for donkeys years. His car is very well sorted with constant minor development over the years. As I remember he had an engine rebuild done by a French specialist when his engine went bang a good few years back so wouldn't be surprised if a few tweaks were incorporated. The standard A610 turbo is a decent turbo and will comfortably make over 300bhp without going silly with the boost, the issue has always been ECU and fueling related both needing major mods to run that sort of power.

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Well in keeping with sharing your failures (warts’n’all) as well as your success in posting power runs up here, here’s my latest session at the rollers with my background project - the boys (LTH Coachworks) F50, here: viewtopic.php?f=8&t=4899&start=30

So it’s a 2.5ltr (OE bottom low comp bottom end), A610 profile cams, OE exhaust headers, single turbo, OE Renix ecu, and air-to-air intercooler.



That’s 332hp, 274lbf-ft at the engine… what went wrong then Faulksie… well it had been one of those… lol… yes it was a 2am start, hadn’t fired her up since my EPROM emulator died etc etc… anyway, the what’s up is that the maximum boost I could get was a measly 0.5 bar… yes 7.35 psi… So that’s 332hp, 274lbf-ft at the flywheel at 0.5 bar / 7-ish psi.

This is a great little thread (is actually a good read):
http://www.allpar.com/eek/hp-vs-torque.html

I do like this bit of fun though… “First, a clarification: torque is no more real than power. The DOHC puts out 133 ft-lb of ground-pounding torque, but I've seen some older Neons that are leaking torque and you have to avoid driving behind them because the torque, once leaked, is slippery. Don't bother picking it up and adding it to your engine as it degrades quickly and will take you out of Stock class. Consider torque and power as concepts used to describe how things interact to produce movement and how "energy" (another concept) is transferred..."

So my slippery stuff has slipped off, and if anybody finds it please send it back to me! Lol… We’ll in a more mundane fashion I knew I had a turbo problem, as it wasn’t spooling up, and I have now stripped it off and found the culprit - I had too little clearance between the turbine and the turbine housing when I built this particular combo up, lesson learned, don’t get too greedy… The turbine has been merrily trying to grind itself into the housing when it gets hot and consequently killing the shaft speed, and hence boost… I’ll put pictures of the turbine etc on the F50 thread when I get the chance…

Anyway, off to the forest I go, and start gathering some more slippery stuff and I’ll be back…

Cheers,
Martin

Did you really rev it all the way out to 7000 rpm? I thought the limit at 6200 was pretty much hard coded, or have you found the enchanted key of the Renix elves?

Bless you! Some good baseline figures though for an engine almost without turbo!


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Did you really rev it all the way out to 7000 rpm? I thought the limit at 6200 was pretty much hard coded, or have you found the enchanted key of the Renix elves?

Lol...



Yes, correct on both fronts - 6200 is the standard Renix brick wall, and the rpm is correct; I have set the rev limit at 7400 rpm, not saying anymore on that

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So what's your view of where it made the power Martin? All in the head work and cams (this one is ported right?) or something else?

You're basically almost the same as the old Saab low pressure turbos at that level of boost so as Jon says, it's not far of normally aspirated - amazing result.

The fact that you made maximum power at max revs also blows the old DG argument out of the water too as the power / torque curves are nothing like the typical scenario where it's all in the mid-range and tailing off before 5000 revs.

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Hi Darren,

Well over time the setup has changed, and to test different aspects. So it's not one thing that I can point too and say that is the reason - I'm not trying to avoid your question. In it's current configuration I wanted a good base set of numbers for A610 modifications ie what works what doesn't, and this to make sure the right bits were going on Sean's car. After I needed to remove the heads last time, I detuned the cams from JV's spec to run the milder profile A610 cams for the very reason of having a test bed - baseline as close as I could get to an OE '610 setup, principally to get the turbo spec right for the RATs project. Yes I have reworked the heads, and they are the same base casting as the A610, but in this case 3ltr n/a even-fire as they are readily available, however identical in all the critical aspects. I have flow tested these heads, results are in my Bone yard thread in projects, and you will see that l can essentially get the same results from either the 2.5 ltr or 3ltr heads, albeit the one takes more work. l would say these are good heads, but I have put a lot more into JILs and Sean's heads now, and having been through that process there is power I have left on the table with these heads, but that's the nature of continued development and learning over time. I have also only used the OE 2.5ltr exhaust valves, giving up 2mm in diameter to the A610 exhaust valves, and this was deliberate to show backward comparison to testing of other 2.5ltr configurations, and specifically those fitted with the OE log headers, which nicely goes to show the OE 2.5ltr exhaust valve at these power levels is not a restriction. Yes as always the ultimate power is in the head, but also the connected systems supporting it, and then significantly feeding the turbo... the bit I've got to sort out now.. but yes, I think getting the mix right is the key, next stop has to be giving it a nice helping of boost...

Cheers,
Martin

Top work again Martin. What injector size was that running out of interest?

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Thanks Darren, but no not really, ballsed up with the turbine clearance to the scroll housing... bit annoying, just glad it is something like that than a turbo spec mistake / issue etc etc... On the day tested all the usual, leaks etc, and found a few that I need to sort, but nothing that would prevent the boost building, turbo definitely felt more sick as it got hot and we all stood around trying it for feel, smile. When l got it back here, and removed the turbo cartridge assembly from the exhaust housing, it was quite clear what had been going on...

Injectors - 550cc

Cheers,
Martin