i know that some boosted cars have throttle lag. and not to sure how throttle lag is created, but i hear that boosted cars have throttle lag or turbo lag. and im curious as to how the turbo set up created this delay in power?

 

im not following you. can you elaborate a little more? cars with larger turbos have a problem spooling them, thats lag. until the use of anti lag. thats the retarding of timing, and enriching fuel so combustion happens on the way out, spooling the turbo.

im sorry im not sure what you are trying to get at.

 

Say that **** one more time...


Bigger the turbo, more time it takes to spool up.

 

i was wondering why boosted cars have throttle/turbo lag.

so its the time the turbo takes to spool up?

 

throttle lag doesn't exist on drive by cable cars
its the time the turbo takes to spool up?

some drive by wire cars have throttle lag
im not sure when or if any honda's are DBW but if they are and are being modded they most likely will have to run standalone and convert to DBC

i don't know of any standalones that suppport dbw other than I THINK motec supports i don't know of any others or there would be more vw's on standalone because they are dbw since 2000

i know vishnue found someway to control it because he tunes the tt bmw and they are DBW

 

OP are you talking about using a 66mm TB vs using a 75mm TB ?

 

im asking because i had "throttle lag" on my eg after i got a b18b1 swapped in, but its was be cause the guy who did the swap is a dumb **** and i had a fuel leak and it wasnt goin thru the line right when i would press the gas, and also my friend has a boosted eclipse and the throttle lags on it and im looking to boost my ls, and if it happens on my set up i wanted to have some knowledge on how to know its the turbo and how to avoid/correct it

 

i have never hear of throttle lag on a DBC car

 

I think i follow you

A small turbo will spool up faster which means you're in boost faster. A larger turbo will spool up at a higher rpm which is the "lag" we all refer to. The larger turbo will be able to make more power, but it comes with a bit of a tradeoff

 

If you size the turbo right, your boost will develope a little slower, but each PSI will make more HP. So Even if you only hit 7psi by 4k and 10psi by 4.5k for example, it could be more powerful then a smaller turbo than would get 10psi by 4k and 15psi at 4.5k. Sometimes the efficiency of the turbo matters more.


As for the whole throttle & turbo lag baloney, there are two types of turbo lag. One is what RPM the turbo starts spooling, IE making boost, when you punch it from idle. The other is when you're cruising at higher rpm, punch it, and it doesn't hit boost pressure instantly. The latter is the transient response, which is fixed with smaller/lighter turbo wheels & ball bearings, as well as smaller turbo housings & less piping. The former can only be reduced (noticably) with smaller or more efficient turbo wheels & housings.


I think the throttle lag you have on your non-professional swap is due to the fuel issue. If the tip-in is too rich (the instant you increase throttle), it will hesitate momentarily, then accellerate. Boosting a broken setup will result in TONS of headaches, if not destroyed motor.

 

"throttle lag" is only gonna happen with a drive by wire set up. which is when the gas pedal is not actualy connected to the trottle plate but conected to a sensor instead. that sensor tells the ecu how far and how fast you are pushing the pedal. the ecu then "decides" how much its actualy going to open the throttle based on a bunch of other sensors and programing. all these calculations happen almost instantly so the lag doesnt come from time it takes to do these calculations but it comes from the programing in the ecu. the main reason for this is traction control (and to keep idiots from blowing there engines).

im an infiniti tech and we have a recall on the 07 g35 where we have to reprogram the ecu due to this throttle sensitivity. people will push the gas a little and nothing happens then all of the sudden it will take off. that is throttle lag, it has absolutely nothing to do with turbo lag which is what your buddies eclipse probably has, and your civic doesnt have either. you might have a loose throttle cable which will let you push the pedal before it opens the throttle which is a common problem ive seen with swaps but thats not throttle lag.

 

it is real then a boost controller can reduce the turbo lag?

 

No, A Boost Controller controls your boost level.

The only way to reduce lag is a tune or getting a better size turbo that will spool quicker.

 

93
Throttle lag is indeed different from turbo lag. Also, a drive by cable car can have throttle lag. For example, my car has a draw through(carb before turbo comp) setup and has a poor throttle response but a respectable spool due to its inherent design. If I'm cruising and slam the pedal to the floor it'll fall flat on its face from an overrich condition. However, the transition to boost is smooth if I roll on the throttle. An efi car is different of course. I'd imagine that poor throttle response would be indicative of a very bad tune or maybe a bad tps or something like that.

Btw, besides a tune or different turbo, the exhaust plays a very big part in spool characteristics. Not only the mani and post turbo design, but the material/coating as well. And even that's not cut and paste. Say somebody wanted to try an open exhaust over a cat/muff setup. While dropping backpressure(always beneficial post turbo), egt may drop as well, possibly negating the potentially better spool. Therefore, a retune is necessary.
93 93/93

 

i have noticed my motor runs a little rich, how could i fix this, i know some one who could help me do stuff now and he knows alot about BDHK series so its no worries, but i made the mistake of having a bad mechanic do my swap. and could it be the TPS sensor?

 

ok i have said that because i have ear something like about it, the boost controller keep some pressure evry time in the hose and help the turbo to boost a little moore faster !! sooo i m a little glad to ear it didint help

 

You fix overly-rich tip-in by adjusting those parameters via your EMS. Most of them don't let you do that, though. Usually it happens because non-stock injectors require different values. If yours is still all stock, its another issue. If its rich at all RPM's, its either a bad MAP, O2, or TPS sensor. Are you guessing, or have you checked with a wideband sensor?


As for an EBC reducing lag, all it can do is bring it to the least the turbo can offer. Usually a WG w/o any mbc/ebc will crack the valve open a little early, which slows the rise in boost a little. The EBC will force full boost pressure into the top of the WG until just before full boost. If its not set right it will either still lag, or momentarily spike.

 

nah i havent yet i just had the thought that it was rich and then a few days later a few people tell me that when driving behind me it smells rich, but havent gotten a chance to meet up with my friend to check it out 4 sure.