Ben Fegan

Anyone hear anything good/bad about the "Lenz Power Kat" and associated items? The Lenz site is at http://www.lenzmotorentechnikusa.com/ and the products look impressive.

Bill Gregory

Looking at their web site, they seem to have quite an array of products. One thing to consider, if you were to go with their super-duper-swap-everything system, you'll have a system nobody but their agent is familiar with, so servicing options may be limited.

Thorsten S.

Hi Ben,

I think you read my posting from 12.20.2003. What Bill wrote is right: You get a system that only their own factory knows, so you are not independent (but mine works without any mistake ever since 1996 and all new parts you get, except the black box, are Bosch and the catalytic converter is Emitec or Oberland(?)) . And you can get a laptop software, where mistakes are stored (for example mistakes of lambda sensor, temperature sensors for air or cylinder head and so on..). And you have a datarecording system, where you can see, how your engine feels during operation.
The system is not cheap but in my experience the best thing you can get for a 3.2 without opening the engine: It has no disadvantages like all the MAFS I have seen here yet in part throttle an idle and its more powerfull (we tested on the german Autobahn).
Mr. Lenz was called "The Horowitz of microprozessors" some years ago in the magazin "sport auto".
The only thing I don t know: In Germany we usually drive fuel with 98 ROZ or more and the mapping of my car is for this fuel. My car has the high compression ratio (10,3:1), too. I dont know your fuel in USA and the US cars have the lower compression ratio (9,5:1) so you wont get the same power like I have. But I think when you call them, they can explain you these things.
I hope this will help you.

Ben Fegan

Thorsten,

Thank you for your post. Yes, I read your comments on Lenz which prompted me to visit their web site, search the archives here and at Pelican and contact John Desmond. I appreciate the Fact that Lenz is providing a significant power upgrade while maintaining the car's integrity and not just running a cat by pass or euro pre muffler but using a catayltic convertor which apparently does the job in the process.

You're correct... they aren't cheap here either and I would really like to find someone close by who had installed one so I could look/see/feel it before making a purchase decision.

I lived in the Frankfurt area in the early 60's and late 70's. I also did driver's ed at the Nurburg Ring with a German driving club. I envy you the autobahn! There is nothing here that compares either to the Ring or touring on the autobahn.

Thanks again!

Thorsten S.

Hi Ben,

so you can imagine how much fun I have with this car here on the autobahn and the old Nürburgring *g*.
The Autobahn A5 between Frankfurt and Darmstadt (I think you know it-15 km straight on with no speed limit) is the street, where I can drive the car at top speed.
I hope you will find someone who had installed the kit. Its worth every Euro!
Can you tell me the price of the kit in USA?

Thorsten

Roamer

Ben,

I have been looking at doing some major na power upgrades to my 3.2 as well. From what I can tell, the top Lenz kit is a replacement ECU, mass air sensor, enlarged TB, upgraded cams (too what extent, I am not sure), RSR-style headers and high flow cats. While the combination of stock-like parts is very attractive, it seems that the power claims are exaggerated. The top kit MIGHT get you 275 hp, but 300, I highly doubt. Not that 275 would be bad if there was a nice torque curve! There also no mention of what rpms you would be running at. If you exceed 6800rpm you will need new rod bolts, valve springs and retainers, these do not appear to be part of the kit.

By comparison, I have looked at boring out my motor to 3.4 liters, changing to 10.5:1 compression pistons, port and polishing the heads, twin plugging with aftermarket engine management, adding new cams (GE-60 or "S" street cams) and installing individual throttle bodies. This combination, if tuned correctly should get 300hp or more. Cost in parts alone, $~7500.

I am attracted to the Lenz system because the overall cost (I heard around $5k for their complete system) is lower and keeps the stock intake manifold which helps maintain the brake booster and other vaccum operated components. However, without independently verified dyno numbers and more (with all due respect to Thorsten) customer feedback stateside, I am a little leary. As for the euro compression difference, it should not amount to more than 10hp.

If we could get some independent numbers and testing done of an equipped car, maybe then I would feel more comfortable.

Thorsten S.

Hi Roamer,

the kit has NOT a mass air sensor. Where you find at the stock carrera an air volume sensor (I dont know the englisch word), this kit has only a tube (called Venturirohr). The air is not measured, it is calculated in the new ECU by throttle angle (alpha) and rpm (n). The intake air temperatur and the pressure in the intake manifold is measured, too. And you get 6 new fuel injectors, to work with the new ECU. Further you get a metall catalyst and an Lambda sensor. This complete kit costs in Germany ~3000 Euro and produces 240 DIN hp on a Carrera with compression ratio 9,5:1 and 250 hp on a 10:3 car.
With the big throttle body, a special prepared intake manifold (called interference system), a optimized stock muffler and an adapted ignition and fuel mapping you get 10 hp more (for 1600 Euro more).
The 280 hp version (called power flow) has other cams, a variable exhaust system, stereo lambda and, and , and. This upgrade costs much, much more.
The 310 hp was a single car for a special person. It was like the 280 hp version , but with 3,4 liter, ingnition like 964, E-Gas and, and , and. Price? I dont know.
RPMs: My highest rpm ever was 7300! (shifting mistake) for a short time with only stock parts (it was stored in the "extrem storage" of the ECU): I hope you can understand, what I mean. No damage.
The rpm limiter can be set, where you want (mine is at 7000).
On the autobahn my highest rpm was 6800 for 5-7 km.
I read about the rod bolts in US Inernet Boards but I have never heard of a problem with rod bolts here in Germany- only the inner valve spring could make problems, but very, very few.
Last year I talked to a person who worked in the Porsche engine development and he told me, that the real engine rpm limit is 1000 rpm higher, than the limiter. The engine is build with this savety margin. This would be 7250 for a 3,2! When you compare the rev limiting parts of a 3,2 and a 930 turbo, you will see that they are all the same- compare the part numbers. And the turbos limiter was 7200.
So I think this problem is not so big as it seems.

Ben Fegan

I wrote to John Desmond, the Lenz rep in the US and he said that the cost of the base system (injectors, throttle body, software, controller and wiring harness was $3,595 NOT INSTALLED. This is without the metal catalyst. With the catalyst it is $4,495.

I agree with Roamer that those numbers would be about right for the whole kit... for just the base system I think that is way too high.
Especially given the unknowns involved.

Ben Fegan

Thorsten,

Is it the A4 that runs north through Giessen, Alsfeld toward Eisenach? I used to take it north to Alsfeld, over to the Vogelsberg and back... a nice drive!

Ben

Thorsten S.

Well, the kit I have is with big throttle body and it costs 4600 Euros (with catalyst).

Yes, its the same Autobahn but in the other direction. And its the A5, not A4.

Thorsten

Roamer

Thorsten, your english is fine, it is certainly close enough for us to put things together. Far better than my german, french or spanish!

It sounds like the air flow sensor is really a manifold pressure sensor. A straight TPS based sensor would only use air temp, rpms and throttle position. Manifold pressure sensors are probably the best type of air flow measurement.

The numbers you just quoted seem a little more accurate. The "specially modified" version you mention sounds a lot like my proposed build up. However, the pricing becomes a little high given that for $7500 I get 6 individual throttle bodies as opposed to re-using the stock intake. In addition, the kit seems to include things you don't really need, like new injectors. The stock injectors, with fuel pressure mods, should be able to handle 270-280hp. (I think it may be a case of impedance matching with the ECU)

Despite this, it seems like a nice kit, but since you can get 240+ hp by using stock internals with a new chip, SSIs and a new cam (~$2500), the incremental increases provided by the Lenz system are pretty pricey.

I will reiterate this, . . . if there were more details provided on the kit (not just marketing lingo given to the parts), and independent testing to verify the claims and address the driveability issues, I think many of us would give it more serious consideration. An article in Excellence sure would not hurt!

Thorsten S.

Hi Roamer,

thank you for the flowers :-)
Did you read the pdf discriptions on the hp?
They explain the system and the kits.
Yes, you are right, the injectors are for the impedance matching with the new ECU.
You can be happy: In Germany the SSI kit costs (only headers and muffler) 2500 to 3000 Euro.
My calculation was this: In Germany you have to pay tax for your car. Since ~15 years, he high of the tax depends on the smog behaviour of the car.
For a car with no cats, you pay 25 Euro/year for each 100ccm. Example: For a 3.2 with 231 PS you have to pay 25*32= 800 Euro/year!
For a car with cat you have to pay between 0 (an actual new car like 996) and 10Euro/100 ccm = 320 Euro.
So I will save 480 Euro/year.
With the original Porsche factory afterparts (? ) cat kit for the 10,3 :1 engine I would only have 207 hp (because the necessary unleaded fuel for the cat was only avialable in 95 ROZ, when Porsche developed the kit in the early 80s)- And for the 10,3:1 engine with 95 ROZ they had to change the ignition timing heavily. And the newer aftermarket chips are illegal because of the German TÜV). So this was no solution for me.
Then I read a very positiv test in the magazin "sport auto".
So in 1996 I bought the 250 hp kit (3450 Euro). Now, 7 years later, the investment had payed for itself (7*480=3360). And in 1997, when I was sure, that I will never go back to stock 231 hp (no way!), I sold all old used parts (DME, injectors, air flow meter, pre muffler) for ~ 600 Euros
Sone I will start to "earn" money with the kit and more than 250 hp (big throttle body/"interferrenz" sytem and adapted ECU in 2002) instead of 207!. Time is money.
In 1996 I made an other calculation, too: My 89 3,2 costed 90000 DM (today 45000 Euros) when it was new.
So I had to pay (45000/231) 194 Euros/hp.
Now, with the Lenz kit I got 19 hp more (194*19= 3700 Euro).
So you can see, its Porsche rate (and quality) :-).
And we know how expensive Porsche factory power kits are.

But now I have a question: What is Excellence? Is it a car magazin?

Thorsten

Roamer

Thanks Thorsten. Is there any way you could get us a copy of that article?

As for Excellence, it is one of the more popular Porsche magazines here in the states and does a nice job evaluating modified Porsches of all types.

As for the SSI's, which I already have, they probably don't flow nearly as well as the Lenz exhaust system which seems very similar to RSR products. As for emissions issues, many states have begun to conduct emission testing during annual inspections meaning that SSIs may go the way of the dinosaur. So the Lenz system having high flow cats is attractive to many of us here stateside.

As for the info on the Lenz web site, it provides insight but not specifications. I have no idea the construction of the exhaust systems, the method of ignition/timing control, the aggressiveness of the cams, etc. I am also concerned about the use of e-gas which I am not comfortable with no matter how many manufacturers are using it now. I prefer good ole mechanical connections. Also, dyno numbers are advertising when supplied by the manufacturer and not an independent lab. If someone like Excellence did a critical test of the various kits with dyno results I think the buying public here in the states would be much more receptive.

The Lenz system certainly has promise, but that promise needs to be proven.

Thorsten S.

Hi Roamer,

sorry, but I dont have this magazin any more.
What I remember is, that they presented a 9,5:1 Carrera with 240 hp. It was a short test on only one page.
They wrote about the good smog values, that the kit is accepted by the German TÜV (very importend for us) and that it was measured faster from 60 or 80 km/h to 120 km/h in 5. gear than a stock car (I think 1,5 seconds, but Im not sure).
At the end they wrote, that this kit is a convinced solution for aftermarket cats.
I think, if you want more technical facts, it is best you call to the representant in USA. Perhaps you can tell him, he should give a car to Excellence for a meaningful test.

Thorsten