Daily diesel

[p_b82]

Originally Posted by ZS Phil

Have you not got the controller yet Pete?
I remember in 2011 I think it was when I first fitted my VNT there was promise of a stand alone controller, surprised it hasn't made it to sale yet, there is obviously demand for it. Lack of a decent controller is why I sacked the VNT off in the end.

No controller still has not appeared, it nearly did a few months ago, but then it was faulty when it was finally tested.

Problem with the PCB, so Kris had to start again.

There is a demand, but most people will not tolerate the time

If I had not bought a GTB, & exhaust manifold & downpipe from Ade that is sat waiting to be fitted, I'd have detuned the car and just admitted defeat tbh - too much lost money if I don't see it through, however long it will take!

Originally Posted by Mark S

it was the 75 http://forums.mg-rover.org/mg-zt-rov...e-ebay-146524/

whilst the marketing guys made big noises about how great a rehashed old rover motor was compared to fiat and bmw's the same people also told us the sv could have 1000hp!!!

only recently have modern diesels been outputing 200bhp from a 2.0 from the factory, granted back in 2006 alpina tuned the BMW variant to 200bhp with a hybrid turbo (needed 2,000rpm to get going) injectors, intercooler etc, but similar to stock boost levels and ultra clean emissions.

The fiat JTD only made 180bhp with twin turbo's in the day.

Ford could only dream of it back then, as could the French, even the rather brilliant 2.2hdi with its twin turbo's did 170bhp, the same motor went on to feature in the mondeo 155bhp and revised into the jags.

Only today with piezo injectors, 2000bar common rails and the latest gen turbo's are we seeing 200hp/2.0ltr on the sporty diesel models out the factory...
So when rover say in 2005 they could get 190bhp from a rehashed old motor and still make emissions, no doubt still an 8-valve head, and given all the marketing bs they fed in the past, I have trouble believing them!!!

The G-series was 16v - and as I understand it, it was not marketing that came up with the figures, it was test bed results.

I think a lot of manufacturers purposely detune the diesels while it was not 'cool' to own one, as they'd rather not show up the petrol models.

With VNT rather than twin turbos it is easier to keep emissions down if you get the fuel mapping and vane control right - but I'll admit that the emissions tests required for legal passing would have limited a lot of vehicles until common rail came out.

If diesels were tested on the actual emissions on the test not just particulate count the aftermarket tuning scene would not be as viable especially for our old tech engines. Hell the recent scandals have shown it is tough for even the manufacturers still!

[Mark S]

Originally Posted by p_b82

With VNT rather than twin turbos it is easier to keep emissions down if you get the fuel mapping and vane control right-

The issue with a vnt big enough to provide good top end without crudely overspinning it (like one french manufacturer whose cars suffered lots of turbo failures before it was revealed their map overspun the turbo) is getting it going whilst keeping it clean.
The mappers (word used loosely) tend to chuck in more fuel to get it to spool, and they often smoke a little (or a lot) whilst they build boost.

A twin turbo setup on the other hand usually has the small turbo boosting at 1100rpm, crossover around 2500rpm depending on setup and still good strong boost at the high end of the rev band without excessive emp and or emt.

The twin turbo setup typically produces more power for longer with higher ve .
In view of this I struggle to see how a turbo with a smaller window 'is easier to keep emissions down', tyhe manufacturers work hard on emissions regardless of single, twin or triple turbo setup.

[p_b82]

Originally Posted by Mark S

The issue with a vnt big enough to provide good top end without crudely overspinning it (like one french manufacturer whose cars suffered lots of turbo failures before it was revealed their map overspun the turbo) is getting it going whilst keeping it clean.
The mappers (word used loosely) tend to chuck in more fuel to get it to spool, and they often smoke a little (or a lot) whilst they build boost.

A twin turbo setup on the other hand usually has the small turbo boosting at 1100rpm, crossover around 2500rpm depending on setup and still good strong boost at the high end of the rev band without excessive emp and or emt.

The twin turbo setup typically produces more power for longer with higher ve .
In view of this I struggle to see how a turbo with a smaller window 'is easier to keep emissions down', tyhe manufacturers work hard on emissions regardless of single, twin or triple turbo setup.

Ok I'll concede you are right in terms of pure performance where space is not an issue - but on most smaller cars, a twin turbo setup is just not practically viable, thus it is easier to keep the emissions down + keep lag free spooling with a VNT rather than a single big turbo or trying to package twin turbos.

Topic for another day, but compound charging offers a lot of benefits as well, but is a nightmare to actually package.

G-series development had stopped before MGR went bust, they never had anything other than development mules in operation in a couple of 75's, and a ZR/25 iirc - I believe they sold the engine plans off as part of the administration actions during the collapse. I believe they went to Tata or another indian company.

SAIC then were no allowed to use it as a result - My memory might be hazy but I think that is how it went down