Turbo Charging or Supercharging?

[NickT]

Chris Hawes Wrote:Single turbo, poor exhaust note, sounds completely stock. Lots of chrome.
Is that a NOS injector in blue along the top I wonder?

http://videos.streetfire.net/search/del ... 276323.htm

The following car has the tell tale single tail pipe...
http://videos.streetfire.net/search/del ... fda67f.htm

Might be a dump valve !

[NickT]

Rottbott Wrote:I'll be going for a supercharger just to avoid turbo lag. With the EFI set up to clear extra space in the engine bay, and to make the supercharger addition much more simple to do. Then I'll be doing fun things with a computer and touchscreen in the car connected to the brain in the engine. I love having an older car because there's so much fiddling potential compared to new cars.

Carburettors? Shudder. How horribly mechanical.

Nothing wrong with a nice throaty sound of Weber dcoe carbs 8)

EFI - Computer says no !

NickT.

[Rottbott]

stunned_monkey Wrote:A supercharger runs off a belt so it has to go somewhere at the arse end of the engine. All the space created by the efi manifold is up the back. Annoying, isn't it? :-) Still, it gives the chargecooler somewhere to live!

Rob, you have a raft of choices to make then :-) Do you want to efi and boost your stock engine, or run a proper EFI forced induction lump? Interestingly it'll be cheaper and easier to EFI your stock engine and if you blow it up, all the important stuff is transferrable to a "proper" forced induction engine.

The only issue in all this is whether the cam profiles are good for forced induction. The real pain in the bottom is the cams from the Renault turbo engine are transferrable to the odd-fire engine in every way except the drive gear for the distributor.

Before you write off a turbo as an option, I would recommend a spin in the GTA we just did.... and after completing that work, I realised that we can achieve results that certainly won't embarrass by spending a lot less. So that £8500 on the website is way out of whack, and it's looking like a sub £5000 price tag now.

Martin

I know bugger all about the cam profiles, but I suppose changing to higher lift cams can't hurt. I definitely want to do this to my stock engine. I like the supercharger for simplicity and predictability. Of course, putting me in a more powerful car is probably a recipe for disaster anyway!

Would the chargecooler be hacked into the normal cooling system, or have its own radiator somewhere? I hadn't even thought about it. How much improvement would you expect it to give?

P.S. My last car had a carb, and it died a horrible death! A lesson to us all.

[NickT]

BTW if you compress air it will heat up regardless of it being turbocharged or supercharged.

Carbs are easy to set up. Oooh I am showing my age here now !
At least you don't need a code reader or a "computer says no!" technician (used in the loosest possible sence) that parts swaps to try and get it working.

Boring though it is, has anyone had insurance quotes for these modifications? I am curious to see if or how much the premiums go up by !

NickT.

[Tourettes Tony]

Boring though it is, has anyone had insurance quotes for these modifications? I am curious to see if or how much the premiums go up by !

NickT.[/quote]
Theres a £30 difference in my policy, worth paying i think for peace of mind cheers tony

[MikeH]

Rottbott Wrote:P.S. My last car had a carb, and it died a horrible death! A lesson to us all.

Yes, i heard that story

[stunned_monkey]

All the EFI PRVs are batch-fired and it's the injectors making that noise. You can only hear them at idle and only when close to the engine. A modern engine fires the injectors sequentially so you get six little taps rather than one big one per cycle. It's easy to mistake for an exhaust leak until you get close.

We sold him the cams he's using in that engine. Somewhere there're vids of him beating an EVO on a 1/4 mile drag.

*personally* I want a quietish exhaust. Although Hatfield tunnel with Rich's twin turbo, Stuart and Dan all giving it some beans was fun! The 300hp GTA had a strait-through and there's too much of a gurgle for my liking :-)

[stunned_monkey]

Chris Hawes Wrote:Is that a NOS injector in blue along the top I wonder?

No that's his dump valve.

[stunned_monkey]

EFI: Yes, when a modern engine goes wrong, much head scratching results. However, what I'm talking here is an aftermarket ECU where you have absolute control over every smegging thing in it down to the minutest detail, plus a nice little "live gauges" window which gives you all the engine sensor outputs. It's great! "I've got a bit of a flat spot at 3500rpm at half throttle" - hit space bar, swoosh, strait to that point on the map, increase fuelling for that point.... better? Maybe some more advance?

It takes relatively little time to get things working and drivable, but all the fine little adjustments have to happen over time - wait for a freezing cold morning and adjust the warm up curve or cranking fuel enrichments. Once you've got to grips with the software, it's really very simple and a lot of fun. And if you bugger it up, just re-load the last map that you saved a few minutes ago..... didn't you....... ?

Rob: I'm still learning cam stuff too :-) But it's not so much lift/duration that's the issue but overlap. There's lots of clever physics involved with air entering and exhaust exiting an engine, and belive it or not, there's a period when both valves are open - this is the overlap. If you're relying on the atmoshere to push air into the engine, then there is a time delay between the valve beginning to open and air/fuel entering. Stick a few psi of positive pressure up its bum and you run the risk of pushing unburnt air/fuel strait out the closing exhaust valve - this will not usually be large enough to have any effect other than spectacularly failing an MOT on HC output. In race engines it has been used to keep the exhaust valves cool!

Manfuacturers spend a lot of time and effort developing camshafts. Well at least they do today! We've got an old engine that was underdeveloped at the time and capable of a lot more. So we can play with high performance cams and bigger exhausts and get good results. Interestingly the 200hp 2.5 turbo PRV has incredibly mild cams - they were very much playing it safe when that engine was designed.

So where does that leave you.... you will need a free-flow exhaust, relocate the AC compressor and potentially have some pulleys made... oh and buy a supercharger! The chargecooler uses its own radiator and coolant - it runs at a much lower temp than engine coolant. The EFI setup will work a treat and your stock camshafts will probably want re-pinning to equalise the banks but other than that, it should work fine. If it fails the MOT on HC emissions, turn the boost down. If you want to go really bonkers, run stage II cams at the same time, but keep your 8.8:1 compression stock pistons. An interesting project....

[Rottbott]

Would the stock manual gearbox handle it?

[stunned_monkey]

Anything up to 300hp at the flywheel and you don't need to lose any sleep. We reckon the GTA's 300hp at the wheels in in dangerous territory for breaking the input shaft. Supercharging an EFI stock DeLorean engine should push 200+ fairly easily

[Chris Hawes]

Martin, you mentioned moving the air compressor and placing the supercharger on the left. This car (found this on my hard drive dating back years ago, source unknown) has it installed on the right. What do you think of the location, is it easier?

The K&N airfilter won't pickup much cool air there though...

[stunned_monkey]

I tend to approach and engine modification with the question "what's already out there that will fit?". There were a lot of variations on the PRV and apart from a couple of small things, it's possible to build a hybrid like Rich's twin turbo with very few custom parts. I know there's a brackt/belt setup that allows the AC compressor to go at the bottom left, so it seems fairly obvious that the super can go up top - but as with allt his stuff, until yuo try it, you won't know what doesn't wotk :-)

Puttng a supercharger on the right mans re-routing the coolant pipes for starters, plus where's the alternator?

[Daniel Shane]

Two words from me,

Super and Charger

[Chris Hawes]

Back to turbo talk at the moment, check out this setup with EFi



More about this turbo installation can be found at this link:-
http://www.dmctalk.com/showthread.php?t=3605&page=3

The first startup:-
http://s40.photobucket.com/albums/e239/ ... =video.flv

The chap doing this install also knows what is going on in the UK (scroll to the bottom):-
http://www.dmctalk.com/showthread.php?t=3605&page=8