Turbo options

[Bibs]

My turbo is coming out tomorrow and I need to make a decision on what to do.

My options are:

[*]Recon at Turbo Technics. They will fit the 360 ceramic bearings and stuff and I'm sure it will come back like new - cost

[98GT3]

My turbo is coming out tomorrow and I need to make a decision on what to do.

My options are:

[*]Recon at Turbo Technics. They will fit the 360 ceramic bearings and stuff and I'm sure it will come back like new - cost

[Esprit Aviation]

Bibs,

I'm not sure if this belongs here, but thought it might be of interest, so feel free to move it about if need be.

I've recently replaced my turbo oil feed line w/ a -3 SS hose, and the oil feed flange on the turbo w/ an alloy flange that has the -3 male fitting machined on to it. It also has a restrictor orifice 1/16 inch in diameter. Typically this size restriction is most suited for ball bearing turbos.

When I installed the restricted flange, that the boost rises earlier and faster than when it was receiving huge amounts of oil. I'll leave it to the turbo guys to explain why. The difference is REALLY surprising!!! As a bonus, the oil pressure/flow to the engine increased.

The turbo is merely a junkyard turbo off of an '87 Saab 900. The vanes have nicks in them from previous use and the turboshaft is probably a bit looser than it S/B. I am assuming the risk of running it this way indefinitely as an experiment because the boost and acceleration was SIGNIFICANTLY better.

Has anyone else experienced this phenomenon? If it can be verified as being reasonably safe, It can be used to great advantage.

Lee

[Vulcan Grey]

with the oil restriction, and without the ball bearing turbo, you probably have only a thin film of oil, which has less drag, but also less protection from damage to the bushing and shaft...

[mike_sekinger]

I

[mwmackenzie]

or you could get a recon at turbo technics and while it's there increase the compressor size like I did.. T35 styleeee????

Mark

[fjmuurling]

Hello Bibs,

Check the website of R&B (www.ramspott-brandt.de/) they have a new Sports 300 turbocharger as well as reconditioning options.

Freek

[Paula&Marcus]

Hi All, Hi Phil,

I have to contradict here ...

Our PUK-turbo compared to the WC-turbo is not even similar ...

The WC-turbo has a very large intake wheel (larger than ours) and a stock size turbine wheel and one (not two) ball bearings.

Our turbo has a smaller compressor wheel and two 360

[Bibs]

Our PUK-turbo compared to the WC-turbo is not even similar ...

They look the same to me, that's as much as I know! :)

I'm no turbo expert, I've not had one long and I'm trying to decide which route is best to take. I'd like to hear John Welch's opinion on why he did what he did to his turbo, thoughts and reasons why etc. I've had a long chat with a lovely chap at Turbo Technics who has given me their options. The

[98GT3]

Hi Marcus,

when I said they seemed like same beast, I meant that they were both capable of handling the same peek power. Are you telling me that your turbo does all this and also has alot less lag than a standard one? Also how does your turbo get around keeping inlet temps from rising with sustained boost? You never know, I might want one for myself oneday!

Oh yeah................Bibs............your turbo is rubbish!

Phil

98GT3

Edited November 5, 2007 by Bibs

[Autocross7]

Good Lord the prices for these things flying around this post!!!??? Whats the reason for the high cost, a turbo is a turbo when it comes to the important stuff (sands a variable blade pitch compressor side). Mine is a stock T3. A couple years ago I was doing some work to the car and decided, since it was original and off the car, I'd get it refurbished before anything happened.

It was cleaned on the ouside to look new, new berings put in, it was balanced, and total time sent off to Dallas, Texas - and got back was 4 days...

The cost was less than $300.00 USD shipping included. I cannot imagine that the cost has doubled in a couple years in USD... you guys are talking Pounds...?

Cameron

Edited October 31, 2007 by Autocross7

[ragingfool35]

refurbish your existing now

then buy a new variable geometry turbo mid 2008

and get full boost from 1500 ish rpm to redline

and feel like a V8!

[Paula&Marcus]

Hi Phil,

Yes our turbo will be able to produce about the same highest flow (pressure vs. temp).

Additionally it will have less lag than one with a huge compressor wheel. Overall it will perform very linear (like the stock one) without sticking out one rev-range more than another or completely neglecting some ranges. It comes into life very early and will pull continuously throughout the whole rev range.

Of course one can build a much more spectacular turbo. The most spectacular ones are the most easiest to build. For example if you just stick a very large compressor wheel (>70mm) into a stock T3 you will get something that will hugely impress you. Low down torque will be low and the lag will be huge then it suddenly comes into life and will produce lots of torque and power in mid and high mids and then at high rpms and load it will drop again, because of too much exhaust turbine wheel restriction. Actually this one is worse than stock, of course, but initially you will think/feel that it is much better ... of course it is not, its just more spectacular for a short time ... Can you see the pattern ?

No, it will not have less lag than a standard one. BTW, there are three standard turbo-version Lotus used over the years. All have different wheel sizes. The S4-variant is the one with the least lag because it has the smalles compressor wheel.

Temperature depends on the efficiency of the turbo and of course there is an unavoidable additionally upheat because of physical air compression. Generally spoken a small compressor wheel that is spinning like mad with a not too steep blade angle will produce a lot of heat with high flow and high pressure. But on the other side it will greatly reduce lag.

The skill here is to choose two wheels that will work perfectly together exactly for this application.

Of course, one will choose a bigger compressor wheel, because one likes to increase max flow and efficiency. But not too large, because the larger it gets the more lag it will produce, because the small turbine wheel is having a hard time to get this big wheel spinning up to max rpm.

On the other hand a smaller turbine wheel will produce good high rpms on a given (medium) exhaust flow rate, but with higher flow rates (= high rpm and high load) it will be contraproductive because the more exhaust flow the more it becomes a restrictor of itself.

Thats why some turbo-builders do a so called clipping to the turbine wheel. This will solve the problem at high rpms and load, but it will also significantly increase the lag and kill low down torque ...

You see, its all about the right choice.

Of course there are also some other tasks, like porting and enlarging the housings and the balancing. The better the spinning parts get balanced the more refined and more efficient the turbo will work. JFYI, two identical turbos one that is balanced to the highest possible degree and another one that is "standard" balanced will differ around 20-30% in terms of lag and max flow (according to my own observations)

Cheers

Marcus

[BusaNostra]

Good Lord the prices for these things flying around this post!!!??? Whats the reason for the high cost, a turbo is a turbo when it comes to the important stuff (sands a variable blade pitch compressor side). Mine is a stock T3. A couple years ago I was doing some work to the car and decided, since it was original and off the car, I'd get it refurbished before anything happened.

It was cleaned on the ouside to look new, new berings put in, it was balanced, and total time sent off to Dallas, Texas - and got back was 4 days...

The cost was less than $300.00 USD shipping included. I cannot imagine that the cost has doubled in a couple years in USD... you guys are talking Pounds...?

Cameron

Autocross7 in my opinion has the best answer for your turbo needs.

Texas turbo buy lots of parts from my shop.

Your turbo is a T3 configuration. If you are satisfied with the current response (drivability)and power, stay stock.

You can't beat how the Lotus engineers calculated what the engine needs for turbo. No more no less!

If you want a bit of power, with minimal lag, ask to port the turbine a bit

bigger than stock using exducer diameter 2.1 to 2.2 (not more than). Use a 60 T3 a/r compressor 60 trim.

If you want a big power, port the turbine to stage 3 2.3 exducer and use a hybrid T04e .50 a/r.

This will support somewhere at the 400 brackets. T04e .60 will up the power more than the .50.

But.....there is a catch, the response will be late. Can't get two things at the same time.

You go up, the seesaw will tilt the other way (vice versa)!!

Use a 360 thrust bearing, I think the best stable, durable and longivity bearing. BB and ceramic are overrated and breaks a lot, hard to replace. 360 thrush bearing a bit more but only a fraction of the overrated BB.

Stay away with turbo gimmicks.

Stay away from a fancy turbo, they do nothing except drive the price on the roof (turbo is turbo).

Stay away coating the turbo or dress up stuff. Not too friendly to the bearings.

Stay away with Chinese made turbo! ever heard toy 'r' us recalls?

Bunch of them in ebay....cheap!

Feed your turbo with a premium milk--breast feeding is ideal treatment...u know what I mean.

Refurbish will use your old housings replaces all internal parts with a brand

new genuine Garrett parts. Use stage 3 Siemens balancer (150,000rpm). Good as brand new...why spend

big dough?

By the way, shotpinning the turbo housing? ever heard this?...no one does it....except who? maybe me?

You are in overseas? its costly to send the turbo to US. However, Euro has a better conversion vs the $$$ at this time.

Just find a turbo guru in your area & help your economy grow.

Edited November 1, 2007 by BusaNostra

[DanR]

Is there be an advantage to separate the normal exhaust pipe from the wastegate pipe? I see many other cars and claims of improved performance when the two pipes are separated and don't converge until 30cms or so after the turbo. It would mean changing the exhaust housing and fabricating new dump pipes.

[Esprit Aviation]

Bibs,

Your old turbo is a POS! Although, I must say that you have described and documented my turbo perfectly w/ the exception of the broken exhaust blade! Otherwise the similarity is uncanny

This is the reason I am willing to sacrifice it, by potential starvation, for the good of the turbo-fearing people.

Travis/Mike,

The only other factor is that I am using Mobil 1 synthetic 15-50. I suspect that the turbo would be in more serious jeopardy if I were running dinosaur oil.

Minimally, the performance difference is amazing! I would really like to hear a definitive answer from someone as to why this is. Is it because of seal pressure creating drag on the shaft or what?

Edited November 1, 2007 by Esprit Aviation

[Squelch]

Our PUK-turbo compared to the WC-turbo is not even similar ...

The WC-turbo has a very large intake wheel (larger than ours) and a stock size turbine wheel and one (not two) ball bearings.

Our turbo has a smaller compressor wheel and two 360

[Paula&Marcus]

Hi John,

I personally donot like to discuss diametrical convictions in public forums.

Whatever I will answer to your questions would start something like a mud battle ... thats why I wont reply on these questions, sorry.

Marcus

Why two bearings? One annular contact ceramic ball bearing is all that is needed, there is only thrust load in one direction.

Are you implying that the WC Engineering turbos have too much lag? (they have less than stock) that they are un-linear? (most people comment that they drive like a V8 after the upgrade) or are very peaky?

[Squelch]

Hi John,

I personally donot like to discuss diametrical convictions in public forums.

Whatever I will answer to your questions would start something like a mud battle ... thats why I wont reply on these questions, sorry.

Marcus

Marcus:

I didn't start it in public, you did...

I followed up on your public comments...

John Welch

WC Engineering LLC

[Simon350S]

Play nice please boys.......

This is a place of Love not War.....!!!!

If you got a problem, sort it out together in the bedroom......

Simon x

[jfitz981]

Hey Guys,

I would not take this as any sort of confrontation. Seems like this would be a good place to discuss the diffrences between the 2 turbos. Then let us make the decision as to what route we would like to go. I actually thought that these 2 turbos were almost the same, but it now seems they are really different. I would like the comparison to continue w/out bickering.

Jason

Edited November 2, 2007 by jfitz981

[Bibs]

Hey Guys,

I would not take this as any sort of confrontation. Seems like this would be a good place to discuss the diffrences between the 2 turbos. Then let us make the decision as to what route we would like to go. I actually thought that these 2 turbos were almost the same, but it now seems they are really different. I would like to comparison the continue w/out bickering.

Jason

Well said. That's exactly the reason I started this thead. I'd like to know the pros/cons of each so I know which one to buy.

I understand that you chaps are direct competitors and I have invited others to this discussion too but I'm sure everyone can give a 'sales pitch' without anymore confrontation.

The idea is that in the end us Esprit owners will know where to go and why, depending on what we are after.

[t70]

truly.... how does one actually measure this without data? i.e. how long does it take to spool from 0 psi to 15 psi at 2000 rpm start in 2nd gear? and then we will need a dyno graph for each turbo in order to determine where the exhaust housing starts to restrict flow. There's a project... Bibs... you need to get each one of these turbos and put them on your car and do these tests... once you have made you're own personal determination... then we can all learn from an independant, un-biased, objective observer.

[98GT3]

Well said. That's exactly the reason I started this thead. I'd like to know the pros/cons of each so I know which one to buy.

I understand that you chaps are direct competitors and I have invited others to this discussion too but I'm sure everyone can give a 'sales pitch' without anymore confrontation.

The idea is that in the end us Esprit owners will know where to go and why, depending on what we are after.

Bibs, one thing that would be interesting to know is Lotus's take on this, why they used the turbo they did (3 types), and would they do it different now with the advancement of turbo design (leaving out the latest variable types).

Phil

98GT3

[Advantage]

Bibs, one thing that would be interesting to know is Lotus's take on this, why they used the turbo they did

Cost. Cost to buy and potential warranty costs are very high on Manufacturing's list. The designers would have different ideas to the accountants, though!