turbo lag turbo boost?

[jt850turbo]

having just brought myself an 850, and it being the first turbo ive owned im what you could call a turbo virgin. my 850 is running at around 290 bhp, remap exhaust filter, i brought it from a vpcuk member, thanks again shaun850..... ive been driving it for 3 days now and i need a lay man explanation on turbos, lag and boost plz? i have a hks evc 5 boost controller and it means nothing to me as im a little unsure how it, works, effects performance and what the potential of my new long awaited 850 is...... pros and cons would be appreciated thanks......

[AlanG]

Hello JT. 290bhp?,then it is far from standard. The T5 was equipped with the 15G unit which should spin up at around 2400rpm. Sounds like a re-map so more like 265 -270bhp with a Rica 280. You need to have an indepth nosey under the bonnet mate. The 304 re-map is obviously more again...Do a bit of checking bud.

[jt850turbo]

i know as stardard they run at 230/250 im just wanting a verbal lesson on my new beast, being honest ive never owned such a fast car, i know its 15 years old and its way past its sell buy date, and the goverment would love me to trade it in on the new rat race theory 'hey look neighbour im doing so much better than you' motor, but i had a dream, my dream, and its here right here right now in my eyes im now the owner of classic motor, i want to keep her running sweet............... **** that sounds rather weird.....

[jt850turbo]

i should add my wife's getting a little worried allready, its only been 3 days

[p fandango]

i know as stardard they run at 230/250 im just wanting a verbal lesson on my new beast
all normal 850 T-5's are 225bhp, 850 T-5R's are 240bhp & 850R's are 250bhp

glad you happy with the car, but please be careful. Using a remap alongside an additional boost controller can be very dangerous & very expensive if you don't know what your doing. The remap will have either raised or removed the factory boost limit, & using an adjustable boost controller means its easy to wind it up a bit too much & end up bending your con-rods. I would keep the boost around 13psi to be safe

[jt850turbo]

been running mainly with on hks avc 5 off, so running below stock?..... i belive the boost control has 3 settings... off, A and B...... each setting has an 'warning level' witch will cut out before extreme levels of pressure, damage will be done?....... should i remove the boost control? and just run her without..... advice wanted?

[jt850turbo]

just want to keep enjoying her and keep her running?

[JelT5]

all normal 850 T-5's are 225bhp, 850 T-5R's are 240bhp & 850R's are 250bhp

glad you happy with the car, but please be careful. Using a remap alongside an additional boost controller can be very dangerous & very expensive if you don't know what your doing. The remap will have either raised or removed the factory boost limit, & using an adjustable boost controller means its easy to wind it up a bit too much & end up bending your con-rods.

Agreed! Look after those rods or you could end up with a big rebuild bill!


I would keep the boost around 13psi to be safe some of us seem to get away with running higher boost levels though hey Ped ;) lol
as long as the boost comes in progressively, the rods should be ok, however as Pedro says be very, very careful.

[BruceT]

Shaun850 is a knowledgeable bloke, surely a little chat with him would of been good?

I know his car has been proven a solid 290hp on several different rollers and having seen it in person it got a nice exterior.

[The_Rapid_Tank]

This car runs spot on having been in it many times. just use the settings on there and u wont go wrong but dont adjust it. hope u injoy the car i know shaun850 is missing it already.

[cragmaz]

your limit on the std. bottom end is 17psi max, and thats with spot on fuelling, and believe me, i DO know the concequences!!!!, (new engine please!!!!)

Run it at 15/16psi to be safe, but please make sure your fuelling is ££££ on, get the map file read to see what is actually going on, also stick with the volvo BCS, dont change it for a GM one like some people do, cos if it decides to stop working, then boom!!!!, bent rods!!!!!!,
i personally have a good fuel map,and a manual boost controller, (bleed valve) locked off at 16psi, and have a dyno proven 296.5 bhp, and she goes like stink.............safely!

Just be careful mate!!!

C

[t5_carl]

ive seen 22 psi on a t4 lump......never did go pop;)

[p fandango]

your limit on the std. bottom end is 17psi max, and thats with spot on fuelling, and believe me, i DO know the concequences!!!!, (new engine please!!!!)
http://xs142.xs.to/xs142/09355/interior5935.jpg
thats 20.8psi on a stock engine with basically a MBC, air filter & exhaust. Your fuelling may have been "spot on", but your boost map couldn't of been

[t5_carl]

if a 1.6 ford CVH can take 22 psi i god dam hope a volvo t5 lump can :D

[shaun850]

Hey james,

The evc has been on her for sometime and will cause you know issue.

Like I said on the phone dont load the boost up really low in the revs ie flooring it in 4th and 5th for 2k etc.

I had her checked on the rollers numerous times and it is spot on with fueling/det.

If you want to remove the evc then you will need a std boost control solenoied which I can foward to you.

But mate dont worry its supposed to be that quick :)

Adjusting the EVC towards 200% duty will make the car feel abit more laggy but bring the boost in later if you are worried but she will be fine.

hope you friend like it

cheers

shaun

[p fandango]

if a 1.6 ford CVH can take 22 psi i god dam hope a volvo t5 lump can :D
they probably didn't use choclate for the con-rods on the CVH lol

[p fandango]

The evc has been on her for sometime and cause you know issue.
i hope you don't take any of my comments the wrong way, there is no question about the evc working fine on the car (i'm using an Apexi AVC-R myself). I think most people are concerned about the new owner messing with it & bending some rods in the process of learning. Having the boost so easily adjustable can be a big temptation & combined with not 100% knowing how it works, the boost limit being raised/removed could very easily end in tears


If you want to remove the evc then you will need a std boost control solenoied which I can foward to you.
can i ask how you managed to remove the stock BCS without throwing a CEL light?

[cragmaz]

http://xs142.xs.to/xs142/09355/interior5935.jpg
thats 20.8psi on a stock engine with basically a MBC, air filter & exhaust. Your fuelling may have been "spot on", but your boost map couldn't of been

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.

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.

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.

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.

cheers

C

[cragmaz]

ive seen 22 psi on a t4 lump......never did go pop;)

will do soon mate!!!!!!!

[shaun850]

P, I have never had a cel light from removing the BCS on any of my T5's...

They are pre obdII if that makes any odd to ya?

[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 :pimp2:)

[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 :pimp2:)



well, your a lot braver than me matey, :crazy:

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...