I have seen some members put on wheels and stereos but has any one done power performance upgrades on their car? I know we have sponsors here that do such and you may respond but I am expressly looking for problems with these types of upgrades. My local mechanic says I better leave the car alone. I am sure I could but I was looking to make the car more personal and special to me.

More power is good but at what costs in reliability and drivability? What is the downside to an ECU upgrade or pipes?

 

I pretty much side with your mechanic. However, I have noted that on this forum there are many of you that like to modify your Bentleys to make them "more personal and special for yourselves" and I respect that. Mine is just about as personal and special as it can be, just like it is.

 

I appreciate the response my good bud from TX but that's a ball-less attitude. Oh I'm sorry but I'm over here laughing my guts out, at myself. I am sure that i am not as funny as I think I am. but WTH just trying to have a good time mate. You have a new one under warranty right? Mine is an 07 so those days are over.

I do want to consider any risk but have to wonder if the car is not built on the conservative side and some extra boost may be no harm at all. I would hate to learn an expensive lesson.

 

I don't know if many normal people would think that a 12 cylinder automobile with 567 hp to be conservative. And then again, probably no one on this forum is a normal person.

 

Normal persons on here??? Yeh right! we are dead common.

Example to make my point please;

My car is advertised at 552hp and yours is 567hp. The Speed and Super Sports are higher yet, respectively. How do they do that? All have the same motor right? Same pistons ,cams displacement, turbos ect.?

I expect the difference is the tuning parameters of the ECU. If that is the case then we should be able to tune the older stock GT to perform more like the SS with no ill effects.

The question of, is 576 enough power for us is irrelevant. I doubt we really need any more than a Geo Metro to get from home to the office or McDonalds. But NO us normals have these ultra fine Chariots of the Gods.

I welcome lively debate and friendly criticism, even name calling from friends of the forum.

 

 

Installing a free flowing exhaust will not pose negative affects. Allowing mechanical relief of the engine's breathing system is quite beneficial, the only side affects are related to cabin droning caused by poorly tune exhaust systems with major resonance.

As for ECU tuning, if you select a tune from a reputable company that has proven to be successful such as OE Tuning, GIAC or EvoMSiT the risks are minimal.

The issues you will want to be aware of are things like, the tunes allow the turbos to create more boost pressure. To create more pressure they spin faster, spinning faster heats up the lubricating oil and breaks it down, contributing to accelerated turbo failure due to bearing wear/seal failure.

Also, the fuel mixture is richened up. Rich fuel mixtures contribute to catalytic converter wear/failure. With a tune, you're creating an opportunity for accelerated catalytic failure.

The final point of notable consideration (IMO) is that although these companies do their very best to be diligent and provide quality software upgrades, they simply can not invest the amount of time and money into development and tooling as Bosch.

That means there is always the possibility of a "glitch" to be present in tuning software. With high quality tunes, the likeliness is very low but it's still possible. That could lead to diagnostic time from your local technicians in the even of a drivability complaint...occasionally resulting in have the computers flashed back to stock software.

 

Steven that is me.

Josh thanks for the candid comments., that is what I was hoping for. I believe there is no free lunch so the question for me to answer is the "cost/risk" to high? When I get fully informed then I can make a decision biased on solid facts and accept my outcomes.

I would have to ask about the actual probability or incidence of occurrence of the turbo or catalytic failure? I would be changing out the pipes and eliminating the secondary cats, leaving the primaries.

 

No problem, I believe it's ignorant to assume that anything is free of cause and affect.

As far as probability, on the turbos...it's guaranteed that eventually they are going to fail. In my experience with turbo and over-boosted cars, the likeliness of that situation occurring sooner than later varies greatly on the quality of engine oil used and how well the car is maintained. Poor oil quality and overly rich running conditions are a much more serious problem than over-boosting. These issues are even more of a problem when over-boosting...

I consider the experiences I have to be conclusive, and say that if you use a high quality synthetic oil such as Motul and the car is regularly serviced the odds of the turbos failing excessively early are not very high. I have done enough comparisons between stock cars with standard oil and modified cars with very high quality oil that there is no doubt in my mind or opinion.

In regards to the catalytics, some cars such as Astons have trouble with ruining cats straight from the factory. Other cars have trouble because they're not tuned up and serviced correctly. Excessively rich fuel mixtures will destroy catalytics.

If your car is running properly and the tune is setup not just to make ultimate power, but with real world consequences in mind you will not experience unusual failures. If you're mindful that an engine like this is sensitive to maintenance, you will not experience unusual failures. If your mechanics are mindful and thorough to keep it running well and recommend repairs and services properly, you will not experience unusual failures.

There are too many variables for me to promise you over the internet that nothing bad will ever happen. It is perfectly feasible to accomplish what you want and not suffer consequences though.

 

Thanks so much for the nice thorough post.

Regarding over boost, how much is to much? Specifically for the 07 GTC. I would allow for the less than maximum power in favor of street drivability and longevity.

I have no problem with using the best oils and maintenance strategies.

 

Mel,

here are the answers to your questions, i decided to post them here rather than PM you back in case anyone else was interested...

we have never had any Bentley customer dissatisfied with the software tune. Here are the parameters that we change:
·Main fuel maps – Increase fuel delivery
·Desired lambda maps – (request more fuel with the increased fuel)
·Lambda safety maps – (increase to further fuel the engine)
·MAF calibration – relates to above
·Ignition maps – smooth out ignition tables for smoother power delivery
·Boost maps – increase boost to increase power
·Boost limit values – prevents over boost codes
·TQ maps – increase to allow the engine to produce more TQ
·TQ limit values – prevents TQ limit codes and allows more lateral movement TQ
·Airflow maps – relates to the fuel tables and overall airflow if the engine
·Airflow limit values – increase to prevent airflow codes

We are essentially doing what Bentley has done on the sport and super sport models. However we have been doing this since 2004 before these models were introduced.

Stock boost pressure of the 2004-2008 (base GT) is ~0.6 bar (8.82 psi)
Stock boost pressure of the Speed and SS is ~0.7 bar (10.29 psi)
We increase the boost pressure to 0.9 bar (13.23 psi)
These engines can handle as much as 1.2 bar of boost without any problem however we limit the boost to 0.9 bar due to the size of the turbochargers. They are a relatively small turbocharger and boosting them beyond 1.0 bar will create too much heat. We produce a safe power increase with the adjustment of the parameters listed above.

in regards to the exhaust, a larger free flowing exhaust with less bends, less cats (or free-er flowing cats), and deleting the resonators is essential. here is a picture of the stock GT setup (notice how the downpipes flatten out and go into the 2ndary cats and resonators):




here is the fabspeed downpipe (no flat sections):



and the x-pipe that deletes the 2ndary cats and resonators:



the best part is the car still maintains the bentley "civility", it doesnt get obnboxiously loud but does gain a nice exhaust note!

 

Thanks David that is the kind of stuff I was looking for.

 

my pleasure!

 

Well I did it. I ordered the pipes and tuner from David of Fabspeed. I will report on the driving experience after the modifications are completed.

I have summed up me feelings this way. At this level of car ownership needs are not the criteria for judgement, enjoyment is!

 

well put... now send the car up here because I NEED to enjoy it!