Reducing lag?

[edh]

Simon Peckham builds hybrids with a kkk hotside & garrett BB compressor. You're going to be looking at IRO £1.5k + engine management changes (chip, remap etc..) + fitting. That doesn't look too far off the LR prices once you add in shipping & taxes TBH. It may be worth talking to jon mitchell http://www.jmgarage.com/index.htm who uses with Simon's stuff & can give you a good idea of what you could expect.

 

[Diver944]

ORIGINAL: nags

I'm aware that Lindsay Racing offer a reconditioned (exchange) turbo for what seems to be reasonable money, but they do come in for a bit of criticism.

I think that's pretty much unfounded to be honest.

The two most powerful 944's tested in the club both have Lindsey LR75 Turbos. That's Rick and Mark's 400+bhp monsters, they've both been fitted for a number of years now, both covered a fair few thousand miles and still going strong. Marcus Hahnemann's 3L track car also has a Lindsey Turbo, is arguably THE most powerful Turbo that I know of in the UK and it leads a blummin hard life being ragged round many, many trackdays. In fact if you look at the league table from our club Dyno Days, 4 of the top 5 cars all have Lindsey Turbos:

http://www.cannell.co.uk/944%20UK%20League.htm

No they are not the most advanced turbos in the world but neither are they anywhere near the most expensive. They are reasonably priced, they fit, and they do the job (better than the sandard K26 does IMHO). My own custom made turbo cost three times as much (when the exchange rate was better) and it was a big job for JMG to get it to fit, lots of bits had to be ground off and in the end my crossover pipe also had to be customised. It works fantastically and spools up incredibly quickly with almost imperceptible lag.

You pays your money ..........etc

Places for rebuilds in the Uk that I know of are - Turbo Technics, Turbo Dynamics and AET Turbosmart. I've not used any of them for a rebuild.

 

[nick_968]

Speak to Simon Peckham if you want a 'proper' turbo.

 

[nags]

Paul's comment is interesting, I did wonder whether it might be a case of the cheaper US part getting a (possibly unfounded) knocking. The Lindsay (reconditioned) turbos look like they could be had for ~£500, whether or not it works out that way depends on the cost of getting the original core back and whether or not you get hit with tax for the imported item here, from what I understand.
A reconditioned item may well be the first port of call on the basis that the next step up is in the order of £1k more and (I assume) would require a further upgrade to fuelling.

 

[TTM]

ORIGINAL: Diver944
it was a big job for JMG to get it to fit, lots of bits had to be ground off and in the end my crossover pipe also had to be customised.

Do you mean the turbine at the junction with the crossover pipe was slightly offset and had to be ground off somehow?

 

[sawood12]

ORIGINAL: Diver944

ORIGINAL: nags

I'm aware that Lindsay Racing offer a reconditioned (exchange) turbo for what seems to be reasonable money, but they do come in for a bit of criticism.

I think that's pretty much unfounded to be honest.

The two most powerful 944's tested in the club both have Lindsey LR75 Turbos. That's Rick and Mark's 400+bhp monsters, they've both been fitted for a number of years now, both covered a fair few thousand miles and still going strong. Marcus Hahnemann's 3L track car also has a Lindsey Turbo, is arguably THE most powerful Turbo that I know of in the UK and it leads a blummin hard life being ragged round many, many trackdays. In fact if you look at the league table from our club Dyno Days, 4 of the top 5 cars all have Lindsey Turbos:

http://www.cannell.co.uk/944%20UK%20League.htm

No they are not the most advanced turbos in the world but neither are they anywhere near the most expensive. They are reasonably priced, they fit, and they do the job (better than the sandard K26 does IMHO). My own custom made turbo cost three times as much (when the exchange rate was better) and it was a big job for JMG to get it to fit, lots of bits had to be ground off and in the end my crossover pipe also had to be customised. It works fantastically and spools up incredibly quickly with almost imperceptible lag.

You pays your money ..........etc

Places for rebuilds in the Uk that I know of are - Turbo Technics, Turbo Dynamics and AET Turbosmart. I've not used any of them for a rebuild.

It's true the LR turbo's can make good power but they are very laggy. Ricks car isn't pulling 1 bar boost until about 4200 rpm. That is a good 1000 - 1200 rpm after mine currently does. A good large turbo should be able to make 1 bar boost around 3krpm and still maintain good pressure at the upper end of the rev range as well. I guess it is like everything. There are products to suit all applications and all budgets. The LR turbo's are good considering their price and if you're running a track slag where you want the high end power then they should suit your purpose.

 

[sawood12]

ORIGINAL: 944 man

The best benefit from exhaust pulses comes when fitting a twin scroll turbo. You need a speacial manifold/up-pipe for this though, and its a job that needs a manufacturers resources and level of development: you cant just bolt one on... Im not sure that its correct to state that modern vehicles dont suffer lag because they have small turbos and low boost levels either. The 951 is laggy because it is old and road turbocharger technology was relatively new and undeveloped. The DME is primitive and this exagerates the principal problem which is an agricultural turbocharger (which is large and inneficient, hence the lag) and its location doesnt help. A smaller modern turbo will be able to pump more than enough air to exceed the output of high-end 944 turbos and still be considerably less laggy (see my earlier post). Most modern performance cars seem to use a higher boost pressure than a 951: Im saying that off the top of my head though as its a long while since Ive owned one. As a comparitive example my Impreza achieves a peak bost level of approximately 16psi, which is roughly 1.1 bar. Of course; boost pressure doesnt directly affect spool up.....

I agree but I do think that modern cars with large turbo's are almost as laggy as a 951 running similar boost pressures - e.g. the more powerful versions of the Evo's very are quite laggy due to the size of the turbo. If you take things out of the Audi stable they have low lag but they are relatively small turbo's and operate at lower boost pressures. My car hits a max of 1 bar boost pressure at around 3krpm which isn't too bad I reckon as boost starts coming in a few hundred RPM earlier and builds steadily and quickly to the max pressure. But for sure our old KKK turbo's are very old hat now.

I would love to see a twin sequential turbo 951 but I guess you'd struggle for space:-

 

[TTM]

Scott, the trim on a Super 75 is about twice as big as on a K26, so obviously it will more laggy.
Rather surprised that Rick's S75 makes 1bar of boost no sooner than 4200 rpm, my mate's S75 makes 1.0bar at about 3500 rpm if I remember correctly. Perhaps Rick's is a #10 hotside?

 

[sawood12]

Thom, I realise i'm not comparing apples with apples but a good modern turbo of a similar size should be able to make 1 bar boost long before 4200 rpm and probably sooner than my turbo can get there it. I'd like to see how one of Simons turbo's performs.

 

[Diver944]

You already can on Ricks site

Simons old car had one of his hybrid BB turbos fitted to a standard 2.5 (freshly rebuilt) and the chart shows it hitting 1 bar by 3300rpm and and 18psi by 3400rpm

http://www.cannell.co.uk/UKL%20G886PUA-3.htm

The extra displacement of my engine shows another one of his turbos hitting 15psi at 3000rpm and 18psi at 3200rpm

http://www.cannell.co.uk/UKL%20LIL5766-3.htm

 

[nick_968]

What is also important to note is what gear the 1 bar of boost at xxx RPM is taken for a fair comparison and was it done on the road or on the dyno as this will also make a difference.

 

[333pg333]

A lot of nice theory here but not all easily available. Where is the original poster seeing 1 bar? The stock exhaust is very restrictive and the CAT won't help. What turbo is on your car. K26/6 or K26/8? The 6 should spool pretty well actually.
There is a Garrett turbo with mount available out of the US which is bolt on. I'll have to dig up the link. This would be a good modification.
EDIT: Cut and paste this link ( http://tinyurl.com/ctntch ) to the Garrett bb turbo and very nice looking mount. Not sure on the costs but your Pound is still ok, trust me. The LR reco's for 500 UKP seems very expensive for what you're getting. I'm not bagging the LR stuff but am of the opinion that if you're going to make a change, make the best one that you can so you don't find yourself going back in a year later. I'm sure Simon's turbos are very good too by the reputation that they enjoy. Not cheap, but as Paul says you got to pay to play. There are many small turbos out there that would be a lot more efficient than our KKK series. Or you could get a larger turbo that will spool similarly to a K26/8 yet able to produce in excess of 500hp. http://www.turbochargers.com/store/product_info.php/products_id/2128

There is a lot of truth to the line "Do it once, do it right".

 

[MarkK]

I just did a couple of runs to see where my Lindsey S75 turbo'ed car hits 1 bar boost on the road,on my in -car HKS boost gauge as far as i can see at 1 bar i have 3.5/3.6k rpm -its a big turbo thats fine as far as i'm concerned, its pretty hard to tell for sure because there is alot going on and its climbing very quickly to 1.5 bar,it feels really good and pulls like a train.When i drive it back to back with my standardish car (300 approx brake/ chips with BE) the standard one feels quiet and refined but like its got very small lungs in comparison.The modified Lindsey turboed car runs great, starts great.All this negative talk is all very well but Lindsey have a great website,you pick what you want at a commercialy competitive price, from a well constructed internet shop, it arrives and off you go, for me the handful of LR bits( by no means the total sum of parts that went into our project a few years back) have worked great and for some time now..
The world is full of people that always know best/better and there are good alternative choices out there, but there are a few peoples very fast cars out there with Lindsey components and i won't just stand by while people yak(lots of the time with very little or current successful practical experience) negatively about one theory or another about peoples cars especially when after a lot of hard work and effort they work, and work very well thanks.[]

 

[TTM]

ORIGINAL: MarkK
I just did a couple of runs to see where my Lindsey S75 turbo'ed car hits 1 bar boost on the road,on my in -car HKS boost gauge as far as i can see at 1 bar i have 3.5/3.6k rpm

Mark, thanks for the feedback.