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-   -   Still no gas direct injection Pentastar. Why? (http://www.jeepgarage.org/f73/still-no-gas-direct-injection-pentastar-why-55550.html)

RageOfFury 02-27-2013 06:02 PM

Still no gas direct injection Pentastar. Why?
 
The majority of automakers these days are offering gas direct injection in their engines. This technology improves fuel economy and power output. So why doesn't the Pentastar engine have GDI? Isn't it supposed to be Chrysler's latest and greatest engine design? Why is it missing such a key feature?

The new 8-speed transmission is great and all, but imagine if it was paired with a GDI Pentastar.

Let the debate begin! :popcorn:

Marlon_JB2 02-27-2013 06:49 PM

Re: Still no gas direct injection Pentastar. Why?
 
$$$$$$$$

Srt8_hmi 02-27-2013 08:45 PM

Re: Still no gas direct injection Pentastar. Why?
 
It's called the Apple strategy. .

Why put your absolute best product out when you're going to sell every unit you sell reguardless. I mean Kia has had that auto park feature for years. Maybe next year.

FAUEE 02-27-2013 08:57 PM

Re: Still no gas direct injection Pentastar. Why?
 
Direct Injection also has longevity issues due to carbon build up. Not sure if they've fixed it or not, but a lot of Audi/Porsche engines with GDI have major carbon build up issues.

padgett 02-27-2013 10:03 PM

Re: Still no gas direct injection Pentastar. Why?
 
They do have DI, it's just on the diesel. One advantage to DI with a gas engine is that you can run higher compression since the gas is not there to detonate.

Actually in Florida being able to run near-diesel compression ratios on trash gasoline would make a lot of sense since 87 PON is 10-20% cheaper here than diesel.

Have never really thought about it but maybe should look into being able to run a diesel on gas - best of both worlds (but would really need to watch the EGT).

ps I remember seeing that - with no gasoline to wash the intake port, crankcase ventilation just becomes crud. Of course if you could just run the vent into a catch can a la Jaguar...

hades281 02-28-2013 10:08 AM

Re: Still no gas direct injection Pentastar. Why?
 
BE GLAD ABOUT NO DIRECT INJECTION !!!!!

Direct injection in gas engines has caused a lot of problems because of carbon buildup. I've had 2 DI cars (VW 2.0T, Lexus IS250) and owners of both cars have filthy intake ports... It leads to power loss and misfires when chunks of carbon flake off the valve stems and become trapped between the valve and the seat. BMW 335s have been suffering from high pressure fuel pump failures.

It was a smart choice for Chrysler to stay away from DI, especially as they try to rebuild their quality reputation. They don't need those kinds of problems. That being said, the engineers left some space on the Pentastar head in case they want to add it in the future.

Andoskyy 02-28-2013 11:07 AM

Re: Still no gas direct injection Pentastar. Why?
 
Quote:

Originally Posted by hades281 (Post 769662)
BE GLAD ABOUT NO DIRECT INJECTION !!!!!

Direct injection in gas engines has caused a lot of problems because of carbon buildup. I've had 2 DI cars (VW 2.0T, Lexus IS250) and owners of both cars have filthy intake ports... It leads to power loss and misfires when chunks of carbon flake off the valve stems and become trapped between the valve and the seat. BMW 335s have been suffering from high pressure fuel pump failures.

It was a smart choice for Chrysler to stay away from DI, especially as they try to rebuild their quality reputation. They don't need those kinds of problems. That being said, the engineers left some space on the Pentastar head in case they want to add it in the future.


My IS350 also had direct injection and no problems with carbon buildup. not sure what the physical difference was between the two, but with 106k on the clock, it ran and felt like it did on day 1.

I guess the only "downside" was the ticking noise. You could only hear it outside the vehicle...and certainly didn't bother me. Neither did the 30MPG on the highway with a 306HP car.

Not saying all direct injection engines are flawless...but there was no carbon buildup and no apparent downside to the 3.5L DI engine.

Specx 02-28-2013 11:54 AM

Re: Still no gas direct injection Pentastar. Why?
 
Wasn't it because this engine was co-developed with Daimler, they got the DI version and Chrysler got the non-DI version. Who knows, maybe they had some timing agreement and once that's done DI versions will start to come out.

hades281 02-28-2013 01:49 PM

Re: Still no gas direct injection Pentastar. Why?
 
Quote:

Originally Posted by Andoskyy (Post 769700)
My IS350 also had direct injection and no problems with carbon buildup. not sure what the physical difference was between the two, but with 106k on the clock, it ran and felt like it did on day 1.

The IS350 engine has dual injection -- 6 direct injectors and six port injectors. The port injector spray keeps the intake ports clean, and thats why the IS350 doesn't suffer from the problem. Audi is adding dual injection to the new TFSI engines starting this year in some applications to finally cure the 2.0T carbon buildup problems.

My IS250 only has direct injection, and thats why Lexus has TSIBs for carbon cleaning that won't apply to your car.

Andoskyy 02-28-2013 01:53 PM

Re: Still no gas direct injection Pentastar. Why?
 
Quote:

Originally Posted by hades281 (Post 769807)
The IS350 engine has dual injection -- 6 direct injectors and six port injectors. The port injector spray keeps the intake ports clean, and thats why the IS350 doesn't suffer from the problem. Audi is adding dual injection to the new TFSI engines starting this year in some applications to finally cure the 2.0T carbon buildup problems.

My IS250 only has direct injection, and thats why Lexus has TSIBs for carbon cleaning that won't apply to your car.

makes sense, thanks for the info!

FAUEE 02-28-2013 06:04 PM

Re: Still no gas direct injection Pentastar. Why?
 
Quote:

Originally Posted by Specx (Post 769731)
Wasn't it because this engine was co-developed with Daimler, they got the DI version and Chrysler got the non-DI version. Who knows, maybe they had some timing agreement and once that's done DI versions will start to come out.

I bet it was more of a customer based decision.

In a Mercedes, a 30k mile cleaning of the intake for a few hundred bucks is part of the "fun" of owning a German car, and there's no issues.

In a Jeep, it'd piss customers off hugely that they'd have to spend hundreds to have the intake cleaned every couple of years.

I'm sure at some point you'll see it added, because it's a "hot button" item now that everyone wants because they saw other cars had it so it must be better.

FWIW, it's a 12-16hp increase for that MB engine over the Pentastar in the Jeep, and part of that is due to it revving higher. I'd just as well not have DI or those few hp and have a less costly to run engine.


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