Turbo lag, is it such a big deal?

[jevansio]

I always liked the T88 tbh, i never really felt it was that laggy, a new turbo rated to a similar bhp would be a lot better though.

 

Ive done the fast spooling for so long im a bit bored of it now, im not talking of going mad with a turbo, maybe a T71 billet or one of the new BW turbos for 850bhp, i could easily handle losing 500-1000rpm off my spool time and still be happy.

 

T88, ahh the memories:d

http://www.youtube.com/watch?v=5hH53JhzMBo

Yip, pretty sure I'd be happy with a T71 Billet, the T67 has a huge power band, once I'm totally bored with the 67 (or have killed it) I think I'd go with a 71.

[sdistc]

Lag can be good - for example, it gives you great fuel economy in cruise, the ability to drive a big hp car around the streets without feeling you will go sideways if you just touch the throttle (unlike a similarly big hp V8), and a really cool spool up noise

 

It's usually most annoying when racing from a stop or low road speeds - but that can be solved with some nice 2-step action

[Kirk]

i just think we are a load of pussys.

 

 

totaly agree with that statement! No ones got the nerve to push the envelope over here to be fair accept you and a few others but thats cause your a professional nutter

 

As for turbo lag... pah, God invented turbo lag to give everyone else a chance

 

Id rather have a turbo thats big enough to flow enough air for the power id want but also brings power in slower rather than get to 3000rpm and have my face blown off.

Full boost around 4-5k revs would be nice

Edited February 3, 2010 by Kirk (see edit history)

[Gaz6002]

The other point to this argument is that if you could have no lag, you would, wouldn't you? I would. Riding the wave of power created by a turbo isn't the only way to having a quick car.

 

Personally I'd be looking for a system where the power doesn't come on so violently, meaning a smoother torque graph and better driveability throughout the whole rev range. This isn't possible on a bigger turbo because of the way boost is created, so a compromise is required.

 

I went for the small turbo option for the above reason, although IMO even the PHR stage 1 kit comes on a bit too strongly for what I want. Power is OK, but maybe big twins would provide the setup I'm really after.

[JamieP]

Im not sure what you are saying tbh, in one breath you say no lag would best then you say maybe big twins would be best for you.

[Gaz6002]

Im not sure what you are saying tbh, in one breath you say no lag would best then you say maybe big twins would be best for you.

 

 

It's not about lag, but power delivery... if all the boost comes in within 200rpm then the car all-of-a-sudden sees huge stress and the tyres break traction, whereas if the boost comes on slowly but steadily everything is a lot more civilised.

 

That's what's going on in my head, anyway.

[add heywood]

I still love the T88 tbh... Yes it's a dinosaur turbo and I'm sure there are loads of turbo's better suited for performance etc, but the shear thrill of it coming on boost at around 4k is immense. I looked at my dyno graph and I get an extra 300 hp in 1k of revs.. This, to most people would be horrible, but I the kick up the arse is what makes my car scarily quick.

Also if I had a very fast spooling turbo I'm sure I would find myself at "interesting" speeds alot more than what I do now. The set up of mine means that I have to have the right sort of road to give it some, rather than on normal streets around town. For me, this is great.

 

Each to there own at the end of the day. When I get my new cams in I think I just might up the rev limit to 7500 and see what happens... :cool:

[JamieP]

For me its a bit of a compromise between how much lag i can handle and the power output i want, also to consider is how far will pump fuel go, (i cant be arsed with doing a race fuel map) imo there is no point in running a huge turbo/turbos that for 99% of the time when im on the street its not performing to it best because of pump fuel.

 

I have a feeling a 71mm turbo will max out pump fuel at about 850 bhp and still spool reasonably well and i think thats where i want to be.

Edited February 4, 2010 by JamieP (see edit history)

[Matt H]

Well I'm no fan of lag, there's no replacement for displacement as they say, but it's horse for courses.

 

I doubt any of us would have it if we didn't have to, but it's a comprise that has to be made for power.

 

I'd love to try a large engine CC and supercharger combo in the future... or maybe just buy something with over 500 hp as stock to start with!

[tooquicktostop]

Well I'm no fan of lag, there's no replacement for displacement as they say, but it's horse for courses.

 

I doubt any of us would have it if we didn't have to, but it's a comprise that has to be made for power.

 

I'd love to try a large engine CC and supercharger combo in the future... or maybe just buy something with over 500 hp as stock to start with!

 

Very few engines run a true 500 BHP though without forced induction, this is the reason why we get "cheap" power with single turbo set ups

 

Having no lag can be as much of a pain as too much IMO, being on the turbo all the time gets on your nerves around town and sees the MPG suffer

 

I think the 850BHP Jamie craves on a T71 would be as far as pump fuel will allow you to go and keep an element of streetability to boot, look forward to the progress, it will certainly push the envelope in the UK, still considered tame in the US forums

[JamieP]

still considered tame in the US forums

 

If i was to put it on a mustang or dynojet dyno i bet it would see a 1000bhp, that might keep them happy;)

[tooquicktostop]

If i was to put it on a mustang or dynojet dyno i bet it would see a 1000bhp, that might keep them happy;)

 

Ohh I 100% agree, but you know what I mean

 

I do love the slightly tubbed out look of the BIG BHP US forum cars, Those with stock or OEM kits and very clean lines, super wide semi slick rear wheels, oh and 1000 BHP, yum

[Matt H]

Very few engines run a true 500 BHP though without forced induction, this is the reason why we get "cheap" power with single turbo set ups

 

True, but a lot of the stuff now requires much less from a turbo or SC and therefore lag is much less of an issue.

 

If you start with something of a higher CC that's more efficent, then you don't have to stick something as laggy on to push it to the 500 mark.

[CJ]

I remember a while back talking to people about the possibility of running a SC with a turbo. In effect using the SC as the first thrust and somehow using that to get the turbo spooling up behind it.

 

They (cant remember who) seemed to think that the project was a non starter due to development costs etc.

[JamieP]

I remember a while back talking to people about the possibility of running a SC with a turbo. In effect using the SC as the first thrust and somehow using that to get the turbo spooling up behind it.

 

They (cant remember who) seemed to think that the project was a non starter due to development costs etc.

 

Arnout was doing one years back, not sure he ever finished it though.

 

 

[CJ]

Arnout was doing one years back, not sure he ever finished it though.

 

http://img.photobucket.com/albums/v626/mcanny/twincharge-01.jpg

 

http://img.photobucket.com/albums/v626/mcanny/twincharge-00.jpg

 

Interesting. So, in effect, that should give you immediacy off the line and then a kick up the arse when the turbo shoots in - yes?

[JamieP]

Interesting. So, in effect, that should give you immediacy off the line and then a kick up the arse when the turbo shoots in - yes?

 

If it works, yes.

[j_jza80]

The Boostlogic compound turbo setup shoud offer similar benefits in an 'off the shelf' package. Not sure on RHD compatibility though.

 

http://www.boostlogic.com/xcart/product.php?productid=160

 

Personally I prefer the thought of the Turbo & Supercharger route though. It would make a rare noise

[sdistc]

 

It's not about lag, but power delivery... if all the boost comes in within 200rpm then the car all-of-a-sudden sees huge stress and the tyres break traction, whereas if the boost comes on slowly but steadily everything is a lot more civilised.

 

That's what's going on in my head, anyway.

 

I hear what you're saying Gaz, but it just won't happen - the more power you make, the more inherently difficult it will be to have a fast spool. Big twins make it a bit better, but still get laggier the more power you try to push out of them. Cams are the same - bigger cams for more airflow means loss of spool etc.

 

For me its a bit of a compromise between how much lag i can handle and the power output i want, also to consider is how far will pump fuel go, (i cant be arsed with doing a race fuel map) imo there is no point in running a huge turbo/turbos that for 99% of the time when im on the street its not performing to it best because of pump fuel.

 

I have a feeling a 71mm turbo will max out pump fuel at about 850 bhp and still spool reasonably well and i think thats where i want to be.

 

You'll get at least 700 whp out of pump (mine got 730 without a built head) on a safe / conservative tune without meth. I'm not sure how far Ryan is comfortable pushing AFRs and timing, but I know there is a fair bit more possible than the 520 rwkW my car made.

[Matt H]

Interesting. So, in effect, that should give you immediacy off the line and then a kick up the arse when the turbo shoots in - yes?

 

There's a VW polo with a turbo and SC combo!

 

I remember when I was in blackpool years ago there was some moron in one that kept getting up my arse while I was leaving the lights. He pulled into the Petrol Station that I did and got out to talk about cars...

 

His car was dead mint (according to him) because it was a 1.4 with a TC and SC! ooh

[hodge]

The Boostlogic compound turbo setup shoud offer similar benefits in an 'off the shelf' package. Not sure on RHD compatibility though.

 

http://www.boostlogic.com/xcart/product.php?productid=160

 

Personally I prefer the thought of the Turbo & Supercharger route though. It would make a rare noise

 

 

 

I spoke to dusty extensivly about the compount turbo idea and he talked me out of it. He told me that they tried this kit a few years ago on there car and the engine ran so hot it melted almost everything in the engine bay within 30 mins.

[JamieP]

 

You'll get at least 700 whp out of pump (mine got 730 without a built head) on a safe / conservative tune without meth. I'm not sure how far Ryan is comfortable pushing AFRs and timing, but I know there is a fair bit more possible than the 520 rwkW my car made.

 

 

Is your pump fuel in Austrailia the same as ours? do you know what your afr's and timing is mate?

[nigelboyne]

For me its a bit of a compromise between how much lag i can handle and the power output i want, also to consider is how far will pump fuel go, (i cant be arsed with doing a race fuel map) imo there is no point in running a huge turbo/turbos that for 99% of the time when im on the street its not performing to it best because of pump fuel.

 

I have a feeling a 71mm turbo will max out pump fuel at about 850 bhp and still spool reasonably well and i think thats where i want to be.

 

jamie your a god send to this forum. always asking and pushing the limits of the supra. can i ask what exactly your looking for is it a dyno graph to read 1000bhp or are you looking to get the max power out of the turbo by raising the limiter to 8000rpm. your driving the car on a daily basis and if you feel it can handle more rpm go for it. there are people out there you say that 8k /8.5kand over 900bhp the standard engine can cope.

[RobSheffield]

there are people out there you say that 8k /8.5kand over 900bhp the standard engine can cope.

 

There are people out there that say the moon is made of cheese, but you are probably best off not believing them

[CJ]

There are people out there that say the moon is made of cheese, but you are probably best off not believing them

 

Ah bless