Turbocharging and Intercooling

Nitrous-oxide and propane. No need to mess with any of the engine mapping just a new clutch.

Dunno about diesel SAAB's but the IC on petrol ones is a front mount the size of the rad. It fits up to the slam panel where the rad would be and the rad sit's behind it about 2" back from where it would normally. They are consider a cheap (£10 - £20 from scrap yard) effective upgrade for Nissan side mount IC's on 200SX and will cope with boost and air flow for up to 300bhp (on petrol). Due to having over 2x the number of air tubes it has more flow area and much less pressure drop, this results in an increase in WOT manifold pressure of about 2psi. On a diesel it will do nothing (extra air may reduce full thottle smoke) as you need to increase the fuel to burn that extra air. If you have a common rail injection it will need chipping. Dunno what you do with injection pump systems as they use a 3d cam. If the wastegate actuator pressure hose is tapped in after the IC then it will still limit the boost to the same pressure and you won't see this gain from reduced pressure drop in IC.

New bhp = bhp x (new boost/old boost)^0.5 = 170 x (13/11)^0.5 =

Diesels don't suffer from so much heat transfer from exhaust side as they run with excess air except when at full load so turbine runs cooler. They never pump against a throttle restriction and have full throttle air flow at idle and part load. As diesels don't have detonation problems they are not so bothered by hot inlet air as turbo petrol engines. So they don't need as much IC as petrol.

Found this turbocalcs spreadsheet - it's for petrol. It will show what airflow (grams/sec) gain can be had from reducing pressure and increasing temp drop in IC. Pressure rise as new bhp above. A drop in IC outlet temp from 80°C to 70°C is worth about 3%. I'm not too arsed about working out potential power and what fuelling is needed for Diesel, so you will have to sort that yourself from expected air fuel ratio and density. You need a compressor map to get compressor efficiency and have to take guess at volumetric efficiency. The expected power is all a bit "pie in sky" as you need to know the brake specific fuel consumption / or efficiency

-- Peter Hill Spamtrap reply domain as per NNTP-Posting-Host in header Can of worms - what every fisherman wants. Can of worms - what every PC owner gets!

Brian, f*ck off, you don't know your arse from an APC. Saab have been using knock related boost control for the last 20+ years. The APC (seperate in early cars, included in the ECU in later ones) is a complex boost limit and rate curve controller. It used coolant temp, intake and head temps+Knock noise to control boost to avoid head damage as Saab use relatively high compression ratios for full pressure turbo engines.

Intake heat + high compression+low fueling equals knock. Higher boost through a standard turbo equals more heat through a higher dynamic compression ration and through friction heating. A more efficient and larger intercooler will do a better job of allowing the denser more compressed air to flow, while also cooling it better on the way to the intake.

All this is proven turbo theory and practice. An inefficient intercooler will increase lag as will unnecessarily long intercooler pipework between the turbo and the intake, or un-needed bends or lumps inside the pipe.

CO2 sprayed on the outside. -c intake temps. Loverly.

Actually, CO2 injected straight into the turbo on the exhaust side is enough to keep the turbo spinning up. hit it a second before launch and you get boost almost straight away.

The Americams have been playing with it.

Hmmm... Car is fitted with turbocharger and a variable fuelling tweak thingy - a bigger intercooler should allow more boost and then more fuel can be added, that makes more power...

Indeed, a bigger intercooler alone will make no difference under normal conditions, high load low speed might be improved a little. But it should allow everything else to be turned up a little.

Oh, remind me where your garage is - as you have such disdain for your customers I'll gladly disrecommend it.

Probably make more difference than sticking it in your oil.

every six weeks

Fitting a bigger IC on Gran Tourismo gives me a 20-40bhp difference in my Subaru, I don't think anymore needs to be said on the subject :)

Gran Tourismo FTW

good answer there :) BUT fitting a bigger cooler now rather than replacing the normal goosed one with the same size will limit the potential later on in the tuning game

and what happened to the accord?

More fuel is already added automatically because the fuel pressure remains at x psi over manifold via a three port regulator at least with petrol, diesels also add more fuel with more boost.

Yes it will because cooler air is more compact and more of it fits in the cylinder.

high load low speed might be improved a little. But it should

You mean mid to high speed at high boost WOT conditions surely???

That is for the 9000. the GM 900 and the early 9-3 have a much small inctercooler behind the=20 lower bumper area.

--=20 Carl Robson Audio stream:

Heh. Bingo.

Too slow...

ITYM "Didn't run on diesel and I was unable to pretend that it did by driving like DervMan(tm)"

(c;

Heh. 41 mpg wasn't bad, to be fair...