Lets face it, there aren't a lot of twin-charged/turbokompressor setups out there. I think Eric at Helix told me he had installed 16 of the turbokompressor kits. There's not enough data out there to make many generalizations. I've followed all of the pertinant threads on NAM and other boards. Here are the issues that I've seen come up Please feel free to chime in with more, correct or edit my list:

1.) Stable performance ip to 23 psi of boost, above which you are in trouble without beefier internals.

2.) Intercooler boot failure with long periods of high rpm running (read road racing). To be fair, Grass Roots had similar problems with 19% pulley on the track.

3.) Clutch wear. This may be driver-related or inadequate clutch (stage 3+?).

All this said, I'm scheduled to have my turbokompressor installed this month.

 

Reliabiliy/depedability is a REAL concern, but we need a better cross-section than the two guy's you know about (or ingsoc referencing Jan/Eldiablito) before we start implying that T/C cars cannot be tracked due to reliability concerns.

RE: Maximusmini's clutch... he's not exactly running a basic T/C car, if one can claim such a thing as 'basic T/C' Others have run the OE clutch for a while. We're not all as skilled (or concerned?) with our application of clutch

As for driving school... I suspect we can all benefit from driving school & track time. But that's control - how to use the power... a faster you, not a faster car. The end result might be quicker lap times, but its not the same thing.

Thanks for sharing your perspectives

EDIT: Too slow Veni Vidi Vici - beat me to it.

- My intercooler boots were failing with 15% pulley & a few other mods. Can't be T/C specific, though maybe a sure issue. Good to know.

 

tru that, im all stock under the hood (JCW) and i blew a boot.

 

"An engine flat out [or at any percentage throttle] produces more boost when climbing a hill, for instance, due to increased load on the engine."

???


I disagree. Boost is a function of rpm and throttle positon. The boost would be the same going up a hill or on the level at the same throttle and rpm, but the load on the engine, specifically the pistons and rods would be higher going up the hill.

 

 

It's times like this that I realize that posting on any of these forums these days is usually a mistake ....

 

Can you clarify what your beef is?

 

Huh

I wasn't being sarcastic or disrespectful. My point was that neither your nor my experience with T/C cars is representative of the whole. Nothing more.

I asked you because I believed you were better qualified than most to comment. You own a modified MINI, have spent a substancial amount of time on the track, and I assumed your experience would afford greater perspective.

I realize my question was of a speculative nature, and thus your answer is on base. That said, I'd hoped you would elaborate - specifically regarding the drivetrain... Issues that concern you... or problems you'd heard of... maybe related issues you have personal knowledge of from tracking your own car. etc.

 

With a turbo'd car, it's a little different. My understanding is the turbo spools on exhaust gasses, whereas the s/c is driven by the crank (RPM related). So with turbos.... The more load on the engine = more exhaust gasses. The more gasses = more spool. The more spool = more boost.

...or maybe I don't get it...i have been wrong before

 

that is correct....as a sum

 

Boost is a function of load and airflow. The boost control, be it a waste gate or just the ultimate flow of the exhaust or intake will determine maximum boost. That's not to say throttle and RPM don't come into play but load, such as a hill, is a huge factor. Given enough load you can build tremendous boost at low throttle angles and RPM that you cannot on flat ground but it's rare in normal driving situations.

On a turbo vehicle you'll often find yourseld backing out of the throttle to maintain acceleration and boost in normal street driving conditions. It's not a linear relationship like a blower. Obviously a the mini boost level follows the VE curve of the motor but boost is a function of RPM and throttle angle with the blower.

 

Don't mind me, I'm just being a big baby these days ....

 

My reply is in line with Tuls, et al. Sorry.

 

onasled,
i started this thread to hear facts regarding my driving style and what would be best for my application, it seems it has turned into a theory based tc thread. i really did not want this. so far the only info that means anything is yours, tuls, and maximus, you guys have gave real situations that you all have seen or experienced PERSONALLY. i really think this up hill and load thing is for a different thread. we must all realize there is NO 100% SAFE engine mod, my car drives and handles very nicely at sustained rpms the way it is. the problem is getting beat by a (ugly) subaru from a red light. this is why i am trying to decide tc or nitrous. the tc route sounds great as long as the motor holds together, i would creme myself with this kind of power 100% of the time, but i don't want to be wrenching every time i beat my little car. so please anyone who has experience with long periods of WOT using tc please chime in and give your experience. i am sure there are more people with my concerns. this is why i was leaning towards the 40 shot of nos, to kill rice burners. if tc proves reliable with this kind of driving i would change my mind.

thanks to all for the info

 

I just don't like the idea of the bottle you keep having to fill. The stresses of similar power adders will be the same. And having it on tap all the time with the TC is a real plus. And it doesn't take up room in the very small trunk, as a bottle does.

Matt

 

i agree with filling the bottle, though a 40 shot should last about 30 pulls, problem is i will probably get addicted! at 50.00 a fill, the tc would pay for itself in about, oh, a month, ha.

 

I realize that turbo boost is a function of exhaust gas flow. My point is the amount of ex gas depends entirely on how much air the engine is processing which is a function of rpm and throttle position. I think the confusion comes from the fact that you need a load on the engine to maintain rpm and WOT. that load can come from air resitance, friction or gravity. The point I am making is that an uphill load does not cause more ex gas flow, it it the engine processing more air that does it.

 

Cool
So you're saying at WOT (which is one of the key factors in this thread) with my t/c'ed car (which is another point of this thread), I'm going to see the same boost level on level land at a given RPM in a given gear as I would climbing a hill in that same gear and same RPM. So in other words, although there's additional load on the engine when climbing, there won't be any boost level differences?

 

You will accelerate faster on level ground than going up the hill! WOT is maximum umph (to use the technical term)....

The point you're trying to make would make sense if you're not at WOT, but at some partially open throttle, then going up hill (and holding speed, for example) would have increased load, as you have to overcome internal losses, move air AND lift the car up the hill. The computer would then open the throttle more, and you get more work out of the motor, but it becomes an apples to oranges comparison then....

Matt

 

mmmm I like apples and oranges....peaches are good too

 

We got some fancy ones for christmass that were more juice than anything else. Like little sweet waterbaloons!

Oh, to stay on topic, that's at WOT, tced or not!

 

dominic: that is my contention.
The only way you could see more boost is if the turbo is spinning faster and it would not be if the same amount of air is going through the engine.

compressive load on the pistons,rods crank is a sum of the combustion (pressure x piston area) plus the work load. if the work load is greater (driving uphill, high velocity or a headwind) there will be that much more compressive load on the piston. Boost and conbustion load wiull be the same will be the same.

ingsoc's remark (""An engine flat out [or at any percentage throttle] produces more boost when climbing a hill, for instance, due to increased load on the engine.") makes it sound like your boost gauge reads higher when you go uphill