Power/Reliability

[volkdent]

Originally Posted by speedy

hi there , i ran a cb turbo setup and it was very reliable last year, it was set up so in top gear it was off boost at 75 and would sit there all day at 75-80 because you are running lower compression, off boost the engine will run cool mine ran abou 80c ,
hope that was helpfull
jon

Speedy, I had thought about buying one of those turbo kits myself a long time ago. What sort of HP do you think you have now? The older kits had a bunch of bugs in them(no pun), but I suspect the new kits are smoothed out. How easy was it to get yours up and running well?

Jason

[MX67]

Thank's Volkdent, that's what I call big answer

To be honest, I wasn't asking why intercooler increase engine life, because I have different opinion about that, and before I say it, I waited for You to say yours

I believe that;
intercooler serves as a charger (when we make things as simple as possible). It's main rule is to cool air, so we can put more of it into cilinder and get more power and that is by making engine more efficient. OK, so it's true that colder mixture cools heads better, but the volume of mixture that enters the cilinder is bigger, so combustion temperature is higher (which make our engine more efficient). With intercooler, we always get bigger temperature oscilation, because burned mixture is hotter, and prepared mixture is colder. All we do, is making more temp. oscilations which is (in theory at least) not good for engine life. Remember the reason why Porsche water cooled their engines? Because of the uneven head temperatures and heat oscilations. 959 had hybrid cooling. Cilinders are cooled with air, and heads are water cooled.

We all agree that intercooler increases HP. No argue about that. And that is by making engine more efficient. Modern turbo diesels over here in Europe (VW lupo 3L 1.2 TDI) have efficiency of 43 percent. Good gasoline engines in Europe have 30 percent efficinecy. Diesels efficiency comes with turbos, intercoolers, big compression ratio AND bigger temperature to cope with. They are unbelievely economic and they make big torque. That's the reason why we haven't had a diesel made completely of aluminum until recent (heads are rarely aluminum, but crankcase is ollmoust allways cast iron). Gasolines are often made of aluminum. Toyota made first diesel aluminum engine, 1.4 D4D. Why? Because cast iron is far stronger and it can whitstand that kind of heat which was raised to get more efficinecy. The point is, engineers raised heat to make more efficient engine, like we do with intercoolers. Toyota's engineers reduced compression ratio so aluminum can be used, and less weight achieved.

Intercooler = more efficiency = more heat = decreased life

I agree that intercooler may on some engines increase life, but decreases in most applications. There's too many things that has to be cosidered, so we cannot say that in general intercooler increases life. Actually, I would say the opposite is true, but I don't want to "generalize" things.

Cheers!

[beetle1303]

Theory says that more dense air=more air in the cylinder=more fuel to keep the ratio close to 14.7=Higher energy combustion=more temp generally.
AT WHAT RPM????

In my opinion an intercooler could help an engine achieve a desired HP or TORQUE output at lower rpm due to what theory says. Consider the differencies in temps at low, mid and HIGH rpm, at the heads, exhaust valve, crank bearings and cam bearings. Simply due to the friction involved there are differencies.
so why go for the top end High HP? instead go for all roung torque (mid rpm) and have a more reliable engine...Anyway its torque that makes the car move...so more torque=easier through the gears... use a long diff and an uprated trans and you will have a car that it will be fun to drive, quick and more user friendly (for those that share their bugs with their wife etc. )

Chris

[Superbug Scott]

volkdent,

I'm thinking about going with a 1776 (or bigger) when my current engine gives out.

Your personal story sort of scares me

I don't do ANY work on my bug. While it would be nice to go faster in my VW, really it is more important to be a dependable daily driver that I don't have to lift the engine cover to look at anything besides the oil level.

Sould I give up the 1776, duel carb idea and just rebuild a 1600 when the time comes?

Maybe I should have started a new tread, sorry to hijack.

[speedy]

volkdent
hi there , i bought the car with the cb fuel injection already on it, so it was somewere near , the first thing i did was to fiddle with the dash trim pots and sent it all to sh*t, down loaded the instructions from cb and found a long straight bit of road , took about 1.5 hours to set up, i also had the use of a afr meter , i accept the system is not as smooth the ecu's running off a crank trigger but it is alot better than carbs and no worries with cold starting etc.Last year i was running a 220bhp turbo setup and getting 25-28 mpg on a run although this dropped to 10-15 blasting round town .As for this year am building a brand new engine with a larger turbo mounted ontop of the gearbox and massive pipework , hopefully this will be good for over 300bhp at 15psi , am running without an intercooler untill i can afford a charge cooler ,
cheers jon ]
p.s i made my own wiring harness on the rebuild of the car this year for the fuel injection , so by adding a crank trigger and ignition pack and because i have all the throttle bodies injectors and sensors already with the cb system i only have to buy the new ecu to upgrade to emerald , megasquirt etc , ecu is 30% of most systems in cost .

[volkdent]

Schweet! Looks like your taking your time and building it slowly but surely. It's nice to hear that it works better than carbs. I'd heard some bad stories about the setup, but it sounds like it may be a nice way to go if you're sticking with air cooled.

Jason

[speedy]

Originally Posted by volkdent

Schweet! Looks like your taking your time and building it slowly but surely. It's nice to hear that it works better than carbs. I'd heard some bad stories about the setup, but it sounds like it may be a nice way to go if you're sticking with air cooled.

Jason

the cb setup on mine is about 20 months old and starts first click warm or cold every time , have discussed with several people about alternative systems and to be honest there is no gain to be had at top end power and running a type one motor with around 300bhp on boost it was never going to be the smoothest of rides , anyway the engine is going in the car this week and the brakes going on so may be on the road in 4 -6 weeks (need to wait for panels to be painted )
cheers jon

[volkdent]

Originally Posted by Superbug Scott

volkdent,

I'm thinking about going with a 1776 (or bigger) when my current engine gives out.

Your personal story sort of scares me

I don't do ANY work on my bug. While it would be nice to go faster in my VW, really it is more important to be a dependable daily driver that I don't have to lift the engine cover to look at anything besides the oil level.

Sould I give up the 1776, duel carb idea and just rebuild a 1600 when the time comes?

Maybe I should have started a new tread, sorry to hijack.

Most would agree that a 1776 is about the maximum you can go while keeping longevity up, with a relatively modest expense. Keep in mind I drive the snot out of my cars. My 1776 saw redline rpms on a regular basis. If you tend to be a little easier on your engines, a 1776 will do just fine. RPMs kill, as well as higher compression ratios, so if you don't overdo it you should be fine. I suspect if you kept the revs under 4500 you could build a nice torquey type 1 that would last for awhile.

I guess on this forum, I just assume most people are performance minded, and that comes with higher rpms typically. My M3's tach bounced off the redline at the top of the corkscrew and Laguna Seca all day long, but it's designed to do that, although the more time it spends there the shorter it's life will be. The burning candle thing, you know.

Just make sure whoever builds your motor stands behind it, is local, and can keep the maintenence up. Dual carbs are great, as long as they stay synced, better throttle response and more power.

Jason