turbo lag turbo boost?

[sen]

Shaun can't believe you got rid that car was a credit to you

[p fandango]

NO, mate, you misunderstand me, when i bought the car it was running a rica/hlm ecu, and within 24hrs of purchasing the car, i blew the engine, and after reading the file it was totally kamikazee!!!!, with no boost limit, no ignition advance and very lean fuelling.

Having seen the contents of the RICA map the boost protection is actually better than most other remaps, sounds more like an original Superchips map to me which did simply remove the boost limit then used a MBC to raise the boost

F.Y.I. my car runs blue injectors, a walbro 255 pump, a 19T turbo with r.i.p.to a massive fmic, an m.b.c. locked at 16psi, an apexi superpower intake, an 3" ipd down pipe with race cat, with a single box milltek system and a custom re-map, with a dyno proven 296.5bhp.

not exactly sure what this has to do with the post, but if your interested in specs mine is in the first post of the BT thread (link in signature)

Belive me i know what i am talking about with regard to engines running spot on and it takes a lot of precise setting up with lots of hours doing so to be able to get the power and be safe with it, its cost me thousands to do so, and a lot of lessons and total bull**** learned.

i'm not doubting you do know about engines, i was simply pointing out you stated the maximum boost of a stock engine is 17psi which is obviously isn't

Just imagine how you would have felt blowing all your budget on the right car, and then for it to blow it up24hrs later due to some clown mapping it, who dint have a clue what they were doing.
Its cost me dearly to get it to its present state, i know for def, what i am talking about.

i do feel sorry for anyone in such a situation, however it is always a gamble buying cars which have already been modified, especialy if you don't know exactly who's done what

[daveforber]

Going back to the original question ...

i need a lay man explanation on turbos, lag and boost plz

Turbos work by voodoo. It's essentially just a fan and a compressor and it sits in the exhaust. The exhaust gases turn the fan, which blows air into the compressor where it's, er, compressed, before it gets into the engine.

The result is you get a shed load more air into the engine than without one. More air=more efficient combustion=more power (obviously there must be additional fuel to keep the mixture right).

"Boost" is simply the air pressure generated by the turbo, measured in BAR or in PSI.

"Lag" is simply the time it takes for the turbo to get up into boost. Because the turbo sits in the exhaust and is spun by the exhaust gases, there is a delay between putting your foot down and the turbo responding.

The level of boost is controlled by a boost controller and a wastegate. You probably don't need to know the complexities, but the wastegate stops the turbo from creating too much pressure in the engine by allowing some exhaust gases to bypass the turbine. The boost controller controls when the wastegate opens and, with an electronic controller, by how much.

The mapping is important when you tinker with the boost, because the stock engine management system can only adapt so far and if you push it too far, you'll have lots of air from the turbo and not enough fuel from the injectors. The consequence of that is lean running, getting very hot, detonatation and bent rods = £££. It's easy to push it too far, which is why everyone is sensibly advising caution.

But the bottom line here that you've bought a good car, proven on the rolling road and set up correctly. So as Shaun says, leave the settings alone until you understand a bit more and enjoy the power.

[cragmaz]

Having seen the contents of the RICA map the boost protection is actually better than most other remaps, sounds more like an original Superchips map to me which did simply remove the boost limit then used a MBC to raise the boost


not exactly sure what this has to do with the post, but if your interested in specs mine is in the first post of the BT thread (link in signature)


i'm not doubting you do know about engines, i was simply pointing out you stated the maximum boost of a stock engine is 17psi which is obviously isn't


i do feel sorry for anyone in such a situation, however it is always a gamble buying cars which have already been modified, especialy if you don't know exactly who's done what

Listen pal, all i am saying is that on a std engine,with std. bottom end, the max boost you can run is 17psi, thats it, full stop!!!!!

IPD and MTE only run 15psi on their ecu`s and thats to be commercially safe, any more than 17psi an you will bend the rods, ask anybody who knows these cars, Russ @ RT for instance if you dont believe me.

C

[p fandango]

Listen pal, all i am saying is that on a std engine,with std. bottom end, the max boost you can run is 17psi, thats it, full stop!!!!!

& i've already posted a pic up of my own car boosting at over 20, that was a regular occurance. Now i'd certainly never recommend any set there boost as high as that

IPD and MTE only run 15psi on their ecu`s and thats to be commercially safe, any more than 17psi an you will bend the rods, ask anybody who knows these cars, Russ @ RT for instance if you dont believe me.

the RICA 19T conversion (which a few people on here have had done) runs alot more than 17psi, the conversion does include fitting bigger fuel injectors but still retains the standard internals of the engine

its not as easy as saying "the max it can take is X psi", the rods bending depends more on how the boost is built up. I have heard 1.3bar upto 3000rpm then it can be built up, altho my 20psi was done using a MBC so there was no clever boost stepping (which i can do with my Apexi )

[cragmaz]

& i've already posted a pic up of my own car boosting at over 20, that was a regular occurance. Now i'd certainly never recommend any set there boost as high as that


the RICA 19T conversion (which a few people on here have had done) runs alot more than 17psi, the conversion does include fitting bigger fuel injectors but still retains the standard internals of the engine

its not as easy as saying "the max it can take is X psi", the rods bending depends more on how the boost is built up. I have heard 1.3bar upto 3000rpm then it can be built up, altho my 20psi was done using a MBC so there was no clever boost stepping (which i can do with my Apexi )

well, your a lot braver than me matey,

just out of interest ,IPD only run 15psi with their 19t conversion, but each to their own!!!!!

I would rather be safe than sorry (again!!!!!)

C

[jt850turbo]

just got home from my first proper drive in her, loved every minute, did around 120 miles so had time to get to know her a little better.. i must say most of these were with the boost control on stock setting, seems fast to me on that setting, allthough the differance when switched on is quite something...
Thanks for the lay mans explanation daveforber!
shaun, i went to see a friend today down at 'straightline performance' in malvern and a lad was delivering some parts, he recognised the car straight away, another who cant believe you sold it..

[t5 pete]

The main cause of rods bending is a very aggressive map for example driving in 4th or 5th at 2k and flooring it and the boost builds extreamly quickly and hitting lets say 17 or 20 psi which causes a extream ammout of strain on the rods that why most people go for the ecu up grade as the boost can be controlled and made into a progressive map

[t5_carl]

its a shame such a good engine was made with chocolate rods

[AlanG]

It's all relative. When you appreciate that they were only designed to handle 250bhp at best,then they're pretty able. It's well documented that they'll take 300+ and still be safe. If you want huge bhp then you need to invest in the bottom end...