turbo technics corrado

[pablo_vr6 0]

ok lag is determind by how much u need to get the turbo to boost.

 

If turn the boost right up u tend to have less lag as the boost feed wont be able to open the waste gate so quickly so no exhuast gases escape out of the wastegate making the turbo spin quicker and faster.

 

if its turned right down the waste gate will open alot quicker so u will have more lag due to exhuast gases escaping out of the waste gate and need more gases to get the turbo to spin up.

 

Thank you x 2 8)

[Kevin Bacon 5]

I don't buy that. My 16V T's high boost was significantly laggier than it's low boost....and we're talking a small T25 here. Imagine that with a T28 or T3.

[Kevin Bacon 5]

And if high boost spools up so much quicker than lo boost, why do Subara WRCs need anti-lag to stop the turbine stalling?

[pablo_vr6 0]

Ive ran both T25s and T28s and can safely say that neither was laggier on higher boost. if your two limits are 10 and 20psi (for the sake of arguements) then the turbo will still reach 10psi in the same time before the boost controller opens the wastegate so I dont see where the lag comes in?

 

If anything you would get a stronger 10psi running higher boost as the waseagate just doesnt snap open at X psi but is a gradual opening as the pressure increases. (as what aposegil says).

[pablo_vr6 0]

And if high boost spools up so much quicker than lo boost, why do Subara WRCs need anti-lag to stop the turbine stalling?

 

I didnt say they spooled up quicker

 

the only factor in spooling up time I can think of is mechanical (i.e. bigger turbo, making it a hybrid etc)

[aposegil 0]

ok ill give u example of both my mates

 

Both have uno turbo's one a mkI the other the mkII (and as far as i know they are both the fastest one for each model in the uk)

 

anyway one runs a T25 and the other a T3 equivilant but the both had had all the works done (full ball bearings hydrib etc) along with uprated wastegate (which is needed when playing with turbo)

 

from standstill they both boost up as quick as each other but the T25 once it hits 1.2-1.3 bar thats about it whilst the T3 shots right upto 1.5-1.6 and yes both do have major issues with tranction considering the weight about 700kgs :shock:

 

so yes if done correctly it will make a difference but u just cant bang a turbo on there and expect a difference.

[aposegil 0]

oh and i forgtot to add this is realiable every day cars for these guys

[Kevin Bacon 5]

I didnt say they spooled up quicker

 

Well the longer the spool up time, the more lag, no?

 

Anyway, I give up! Can't be arsed any more....

[pablo_vr6 0]

pic1 - say T25 vs T4 - T25 less lag but runs out of puff

 

pic2 - 2 x T25s with different boost limits - both spool to say 10psi the same but one goes on higher. Id not say the other was more laggy. it implies its a negative thing when its not at all.

 

 

pic says 1000 words and all that

[pablo_vr6 0]

not sure why the thumbnail has waht looks like an ERST in it :(

[CoxyLaad 0]

lol

[aposegil 0]

nice pics lol

[pablo_vr6 0]

nice pics lol

 

Im an artist dont you know ;)

[CoxyLaad 0]

both spool to say 10psi the same but one goes on higher. Id not say the other was more laggy. it implies its a negative thing when its not at all. [{/quote]

 

I see what you are saying and you are right, but that *is* lag, as in the turbo takes longer to produce the desired boost.

and the net effect to the driver will be he puts his foot to the floor and has to wait for the full delivery of power to come, where as the man in the low boost car may not go anywhere near as fast but takes much less time to achieve the desired turbo boost.

 

ah turbo boost.......reminds me of that little button in the night rider car 8)

[Kevin Bacon 5]

Indeed. I hear where Pablo and Aposegil are coming from, but my high boost was definitely laggier than low boost. Vince spent hours on the rollers minimising the lag on high boost, but it was still there, despite his best efforts.

 

On low boost the engine just felt like a torquey, big capacity engine, but on High boost there was a noticable lag and then all hell broke loose and I got that addictive torque rush...... I love turbos :D

 

Same with matey's Impreza. He's got a bug eyed one with an Ecutek remap, Hayward & Scott decat and Prodrive system. When you toggle the Ecutek map (full throttle then press the rear demist button) the lag is very noticable as the map basically increases boost pressure. On the standard map, it's fine. But then you have to expect a small compromise when you go from 220 odd brake to 290 brake at the flick of a switch!

[Adam Darby 0]

thanx for the help everyone

[aposegil 0]

Kev totaly understand where ur coming from

 

but alot of people dont realise that the waste gate can cause so many troubles.

 

the simplest way to see if ur wastegate is good enough for ur engine is go along in a long gear 4th or 5th about 3500rpm where boost will kick in quick and plant ur foot down

 

Oh and ull need a very good boost gauge for this no crap thats reads 1.5 more boost than u really have lol

 

once the car has produced full boost, keep ur eye on the gauge (or get a mate to do it)

 

a good waste gate will hold it or slightly increase right until the end and past the power band

 

a crap wastegate will leak so ull see the boost drop off before u get to the end of the power band

 

It u have a leaking waste gate it will cause loads of problems including lag and slow spin up :(

[pablo_vr6 0]

when I used the Greddy it was excellent - it lets no boost to the wastegate until the max pressure is reached then it allows the pressure thru until the boost comes down to the max again so you get a nice stable boost :D

 

really did work wonders on my fiat.

[aposegil 0]

yeah thats the best way

 

one of my mate has a two stage electonic control which is the nuts and works the same way as the greddy but where u can choice the boost levels :D

 

perfect for take offs with low boost then kick the big power once rolling :D

[Kevin Bacon 5]

a crap wastegate will leak so ull see the boost drop off before u get to the end of the power band

 

Yeah that happened on my 16V T but Vince checked the wastegate and actuator and said they were fine. He said it was because at high revs, the high flowing 16V needs more boost than the diminutive T25 can produce, so the engine was absorbing all the boost it had to offer past 5,600 rpm. It just slowly dropped a psi or 2 from that rpm to the redline....

 

I didn't argue with that as he basically redesigned the conversion and knows a damn sight more about it than I do!!

 

But at lower revs, the T25 is superb and does the job nicely.

 

Oh and dump valves can also cause boost leaks. My mate had a piston type Bailey motorsport one on his Scoob and the boost tailed off as you desribed.... it was the dump valve! He took it off and got 40bhp back straight away!

[pablo_vr6 0]

sometimes the diaphrams can go on those maybe split or something.

[aposegil 0]

yeah the only way to make sure ur dont have those probs on dump valves are to get either BOV from turbosmart blitz or HKS or dual pistons ones like forgemotorsport

 

personally i wouldnt touch baileys stuff

 

p.s Kev i know what u mean about higher boost absordtion lets i get that with my charger ;) ;) lol

[Kevin Bacon 5]

p.s Kev i know what u mean about higher boost absordtion lets i get that with my charger ;) ;) lol

 

That 16V head flows amazingly well in standard trim, let alone modified 8)

 

It absorbs all the boost you can throw at it !

 

Those crazy Americans used to run KR turbos at around 350+bhp and they held together beautifully..... but 2nd and 3 gears were shredded constantly :D

[aposegil 0]

yep sounds about right

 

at the min im strongly thinking about building a 16vT and recon i cen get 350bhp out of if without to much trouble

 

ive even seen a guy in germany get nearly 600bhp out of a 1.8 and according to some guys in vwvortex some guy trying to get 1000bhp

 

now if he does that ill be very impressed :D but cant see how he is going to do it lol

[Kevin Bacon 5]

Monstrous turbo or 3 I suspect 8)