[stevehecht]

I know this is a personal thing, but I'd be interested in finding out opinions as to how much a piggyback tuning box would increase driving enjoyment in the 320/8d. I'm looking at the Kelleners Sport KS 20. See page 2 here for specs: http://www.kelleners-sport.de/images...1220021_en.pdf . It brings hp from 180>215 and lbs-ft from 280>332. What kind of difference (meh/nice bump/wow!) would it make for the way the car accelerates at low/middle/high rpms? I'm assuming that it will make no change in the turbo lag. (Let's leave value per dollar out of the discussion if possible.) I have Sportline/DHP and plan on adding Dinan springs and maybe Shockware when it's released.

[diablo2112]

Originally Posted by stevehecht

I know this is a personal thing, but I'd be interested in finding out opinions as to how much a piggyback tuning box would increase driving enjoyment in the 320/8d.

+1. I'm interested in this, too. I know this is a ridiculous comparison, but I had a 1994 Cummins diesel in a Dodge 3/4ton pickup. It was uber-easy to hop that engine up by increasing fuel rail pressure and raising the boost. That truck became a tow-eating monster, with 700 ft-lb of stump-pulling torque. I towed my Formula Ford and other race cars all over with that thing, to race tracks across the Southwest.

I think the tuning potential for the 328d is pretty high. I bolster this opinion with the observation that the 330d in the EU is the same engine block and heads, just with different tuning and a higher boost pressure. Given that the 328d also has the same post-block power train (torque converter/transmission/differential) as the much higher output 335i, and I think the 328d will easily take tuning without any stress.

I'm surprised we haven't had reports of 328d tuning in the US yet; I'll admit, I didn't want to be the first to experiment and have been waiting on another brave soul.

[Vitoco]

Originally Posted by diablo2112

There's a lot of misconceptions about diesels, including among folks here. Indeed, the new clean diesels such as the F30 328d emit less combined pollution than equivalent gas engines. And the smoothness and power in the F30 328d is impressive. Really. I test drove both the 328i and 335i, my 3 prior 3-series were all E90 335i models, and the new 328d is a fabulous power plant.

Many folks don't understand the difference between torque and horsepower. Simply, HP = torque x RPM. All these folks that worry about the 328d *only* having 180HP should understand why this is. The lower HP figure is a singular result of the lower redline on the diesel, that's it. At all other engine speeds, the diesel outperforms the same size petrol engine. That's the magic of torque. In your 328i - with 240 HP or so - you only get this high output at high RPMS. In everyday driving, even in spirited driving, how often are you above 6000 rpm? A very small percentage of the time. For the 99% percent of driving you do, when your engine speed is below 5000 rpm, the diesel will outperform the same size pertrol engine, that's the beauty of torque.

To be fair, there is one performance issue with the 328d (320d in the EU) diesel: it has turbo lag, worse than the 328i. There's a noticeable lag when accelerating from idle, a good 1.5 seconds or so. IMHO, this single feature explains the lower 0-60 time for the 328d compared to the 328i. Once spooled up, the diesel just hauls and pulls. Wonderful power plant. And, you easily get better than the published mileage figures on the highway. We routinely see 45 mpg+ on the highway with our F31 AWD diesel.

If you can overcome the impulse to dismiss the BMW diesel based on the paper specs and consider the drivetrain in real-world use, I think you'll find like I did that it really is an auto that offers the best of all worlds: good performance, great luxury, legendary BMW driving performance, and all-time best in class fuel economy.

The 320d can´t even outperform the 320i so why throw in the 328i? Hell, the 335i has "only" 400Nm vs the 320d´s 380Nm, does it mean it´s almost in the same league?

There´s nothing spirited bout driving a 4-cylinder diesel with 180hp. Yes, torque is higher than in the petrol equivalent, 320i, but the "rev-span" where you have acces to this torque is very small and that is why torque never outperforms hp in any way. Instead it translates to not having to shift down when making a simple take over, compared to the 320i where you would have to if you want to pass as quick.

328i has 350Nm of torque form around 1250 rpm all the way up to 5000-5500 rpm, which is longer than what the 320d delivers, so that pretty much means it too has some nice torqueish-overtaking abilities without having to break a sweat (change gear). And when driving spirited, you rev the shit out of that petrol and there´s nothing you can do with your 30Nm extra to stay ahead. HP is all that matters in a race if all else is equal, that is also why the 320i with the same power output sprints quicker to 60 - it´s lighter than the diesel.

You have a great fuel efficient engine that is a strong work-horse, it is not an arabian sprinter.

[stevehecht]

Originally Posted by Vitoco

HP is all that matters in a race if all else is equal, that is also why the 320i with the same power output sprints quicker to 60 - it´s lighter than the diesel.

You have a great fuel efficient engine that is a strong work-horse, it is not an arabian sprinter.

Do you race on the street? If you do, you shouldn't. I don't, so this argument doesn't matter much to me. Do you race your 328 on the track? Great! But I don't, so I'm not looking for an arabian sprinter.

[stevehecht]

Originally Posted by diablo2112

I'm surprised we haven't had reports of 328d tuning in the US yet; I'll admit, I didn't want to be the first to experiment and have been waiting on another brave soul.

As you know, BMS offers the JBD so maybe someone has tried that. I may be the first guinea pig you hear from on these boards. I probably will get it done sometime over the summer.

[Vitoco]

Originally Posted by stevehecht

Do you race on the street? If you do, you shouldn't. I don't, so this argument doesn't matter much to me. Do you race your 328 on the track? Great! But I don't, so I'm not looking for an arabian sprinter.

Of course I don't, I'm not fast and furious but spending a lot of time on the road u some times encounter drivers that u end up havin a quick highway dragrace with when the roads are clear. The 320d drivers I've encountered, were left behind. There's no skill involved, it's just a matter of bigger engine vs smaller engine.

You say ur not out for a sprinter yet u were the one comparing and emphasizing on the 320d's abilities and how it could take on the bigger petrol engines thanks to the torque. Anyways, enjoy the very nice work-horse you got and have a nice friday evening

[stevehecht]

Originally Posted by Vitoco

Of course I don't, I'm not fast and furious but spending a lot of time on the road u some times encounter drivers that u end up havin a quick highway dragrace with when the roads are clear. The 320d drivers I've encountered, were left behind. There's no skill involved, it's just a matter of bigger engine vs smaller engine.

You say ur not out for a sprinter yet u were the one comparing and emphasizing on the 320d's abilities and how it could take on the bigger petrol engines thanks to the torque. Anyways, enjoy the very nice work-horse you got and have a nice friday evening

That wasn't me, that was Diablo2112. I'm the one aiming to add the piggyback so that I can have a more respectful showing in those quick highway drag races that I never participate in.

[Vitoco]

Originally Posted by stevehecht

That wasn't me, that was Diablo2112. I'm the one aiming to add the piggyback so that I can have a more respectful showing in those quick highway drag races that I never participate in.

Hahah you're right, sorry dude

Good for you, driving fast can be bad for your health