OC 335d

There's a difference between slapping turbos on a car that was built to be NA than upgrading/modding cars built to be turbo. Sure, with a lot of money anything can be done, that really doesn't need to be said.

llamaboiz

Yep, with enough money you can turn a scion xa into a midship v-12 from a ferrari.

Gernby

iTrader: (1)

While I do almost agree with you, I have to state that from an engineering standpoint that just isn't possible unless there is at least one molecule of the Scion Xa that is exactly the same as a molecule of the Ferrari. If there was a molecule that was exactly the same, then I guess you could do surgery to remove it from the Scion, implant it in the Ferrari, then call it a day...

plex

iTrader: (11)

Exactly..........the best platform to start out with would be the one that's FI from factory. The average person will not want to pay some company for R&D on a turbo setup for the IS350. The easiest way to beat FI with NA would be nitrous.......but that will only last so long and take you so far......

LexFather

Well the most cost effective way is the F/I car. We've seen what just a chip can do to the 335. Its like the Supra tt, 2 grand in BPU mods and you are near 400 to the wheels. That is 480 crank ladies and gents.

The IS 350 compression is way to high, the Blitz S/C ads I believe 90hp or so. But its what 14 grand!!

BMW and Lexus know this, thus the M3 and IS-F are bigger V-8s, not turbo'd 335s or IS 350.

If you got the money though, you can do anything you want. Take Morris's single turbo GS 400 for instance. Made 480 to the wheels for 3rd place at NOPI, losing only to a Mustang and a Viper. Lawd only knows how much $$$$$ he's put in it though!!!!

y2ks2k

Thought I would share this report from an owner of a 335 that I just read today:

He posted this Nov 3, 2007

"
I had a 335i and it didn't like to be tracked very well.

Rear differential failed at 15K.
Turbocharger blown at 22k.
Needed valve adjustment at 26K

I got rid of it before it hit 30k miles. I kept is stock except for brake pads and fluid. I didn't put it thru any more abuse that I put my other cars to. The S2000 was rock solid reliable up to 76K miles when 3rd gear went. My Z3M is still kicking at 86K miles and countless track days. The E46 M3 I had was also very solid and didn't have any issues except high coolant temperatures at the track.
"

Joe Z

iTrader: (10)

Perfect testament to the "Ultimate Un-Reliable Driving Machine"

.

LexFather

Ouch! I wonder how many times he went to the track? It is a lot of abuse on cars.

inxexisten

well turbo charged cars will have more problems due to the nature of turbocharging...

plex

iTrader: (11)

Oh really? What is this "nature of turbocharging" you speak of? Do you realized that the majority of the rigs that pull loads across this country are turbocharged. If anything I would say that turbocharged vehicles require more attention and care but once taken care of they can be just like any other NA vehicle.

FiveOhNine

If we are being honest, to get power, you have two options: Forced Induction on a smaller engine, or an N/A larger engine. Forced induction ALWAYS puts more stress on an engine. That being said, any car will last a long time if it is well built and taken care of.

So, while saying that turbos are unreliable is a generalization for which there are plenty of counter examples, the numbers tend to agree. Anyone who says that turbo engines (in general) don't require more maintenance and are as reliable as their N/A counterparts is
a) Trying to sell you something
b) Trying to fool themselves
c) Lying through their teeth

Part of the reason why turbo diesels tend to last longer is that the engines are differently designed and built to deal with diesel combustion, among other things.

lobuxracer

iTrader: (2)

I disagree. Factory designed turbo engines are typically as reliable as their NA counterparts if the factory is Toyota. My Supra is still running the original turbos with 144k on the clock. 1Sicklex can vouch for it's speed. It is no slouch. It's also pushing 18 psi boost and has been for the last 100,000 miles.

It is incredibly unfortunate that 335i owner is experiencing the problems he is. Supras have never had any issues like he is experiencing even when tracked - the biggest issue with a tracked BPU Supra is brake cooling - nothing else is problematic. Sounds like BMW didn't put enough excess capacity in the 335i to tolerate track days well.

Which brings this discussion full circle - Toyota builds an incredible amount of excess capacity into their engine designs. This is part of why we're all of a mind that FI would work OK with the ISx50. Sure they're high compression, but when you consider how much headroom Toyota allows (as a "for instance" the TT Supra's fuel system is engineered to deliver 500 whp, but only tuned to deliver 320 crank hp from the factory), we're pretty confident there is enough left over to support at least mild boost, and with some mods to the pistons, maybe a lot of boost (can you say 6 bolt mains??? I knew you could).

Saying FI puts more stress on an engine is no different than saying making more hp/litre puts more stress on an engine. This is true regardless of induction type.

The "numbers tend to agree" is an indicator of poor maintenance practices. NA engines are more tolerant of poor maintenance because they won't have turbo failures if the owner doesn't change the oil frequently enough while running conventional oil. This is why the manufacturers prefer NA engines. Fewer warranty issues, fewer moving parts, fewer "good faith" fixes because the general public doesn't want to maintain their vehicles.

The entire reason turbo diesels last longer is because they are designed with a completely different service life expectation. Tractor trailers expect to get at least 300k miles from a engine before rebuild, and many go 500k miles. Cars are designed for 200k miles under average use. Track days are not average use. Full boost more than 1% of the time is not average use. WOT more than 1% of the time is not average use. If you exceed these design parameters, your service life will suffer, and may suffer dramatically as evidenced by our 335i owner's complaint.

llamaboiz

Turbo cars *conversions that is* when done the RIGHT WAY *lower comp pistons/forged everything/proper tune/ect* AND no boost switch are very reliable. Thats the thing thou, most conversions arent done 'right' but done 'cheep' and/or after 1 month of ppl gettin used to the power *kits for stock engines* they put in a boost switch...

I dunno, 335i vs is350 is pretty stupid, sure a chipped 335i is way faster BUT the majority of 335i owners arent speed freaks, speed freaks are the exception not the norm. The majority of BMW buyers are ppl who buy the brand (same can be said of lexus).

Personally i love our 11.8:1 compression ratio/encrypted ecu/dual injectors/everything that makes performance mods so difficult, we cant monkey with our motors therefore they should last a very long time, ever wonder why theres a saying, 'stock is best'? The is350 'stock' is no laughing matter on the street either, ppl seem to forget that here, you dont see threads about us losing to the majority of cars we encounter on the road on a daily basis...

FiveOhNine

But that does not make either statement any less true. How many companies, when making the decision to go NA or not, decide to stick with the same displacement AND a turbo? I believe most decide to go with a smaller engine BECAUSE of the power gains of a turbo.

This is a bit of a 'chicken before the egg' argument that is impossible to substantiate either way. So, either turbo engines require more frequent and substantial maintenance by nature, or they are less likely to tolerate variances in X amount of maintenance than a counterpart NA car can tolerate variances in X amount of maintenance (where X amount is the same for both cars).

I think you have to look at turbos and related components as 'consumable' like belts, brakes, etc. In other words, something that will need to be replaced periodically (Toyota's insane reliability record aside).

4TehNguyen

iTrader: (1)

turbo puts more stress on the engine than N/A, your combustion pressures are significantly higher than N/A. Everythings running hotter and harder as well