Engine build progress

[TTM]

Thanks Tony. Following Nick968's guidance on intercooler design I have had a custom unit made that will go in next. I have been waiting for a set of new intercooler pipes and I should be good to go.

I can hardly believe 14 years have passed since I started this thread. Over here the enthusiasm for our cars is clearly not as explosive as it was but the "3 musketeers" are still around and experience has allowed us to be far more efficient in keeping our cars on top. The last big thing I did on mine was to replace the flywheel 2 years ago, on jack stands, barely breaking a sweat - suggesting there might be at least a very few things about getting older that aren't that bad.

 

[Eldavo]

I’d be really interested in seeing what you end up going for with regards to the intercooler.

 

[TTM]

Well here is a photo. Some trimming and welding to the chassis will have to be done as this was sized for 600hp. We will see.

 

[Eldavo]

That is a big boy! my concern with a big FMIC for me would be that with that and the aircon condenser first that water temps might get too high.

 

[TTM]

With regards to coolant temp the coarseness of the core is important. Mine does not have A/C anymore so that's one less thing to worry about.

 

[TTM]

About one month to go before fitting the new intercooler, at long last. There is nearly 10k miles on the new 16V engine, not so new in fact as it has been in the car for more than 3 years already.

The data logged after a long drive yesterday shows I have a tendency to back off the throttle at high rpm as the car feels really quite fast to me, more so than with the previous 3.0 8V engine with its burst of torque at around 4k rpm but lacked the astounding top end "reach" and more crucially the overall liveliness and outright response of the 16V. More than ever before throttle-based boost control allows the engine to feel like a normally-aspirated Porsche engine with its typical flat torque curve but with about twice the power and the way it puts it down and how it is eager to rev up high allows to push the excellent chassis of our cars to its limits without even trying. Try the same bump in power with an old 911 and you may end in a ditch in the first corner, but the 944 chassis talks to the driver in its usual forgiving and placid manner. Never has my 944T felt like such a complete and alive package. The engine is so peachy and efficient that driving even at legal speeds allows for a genuinely dynamic experience. It has been a long way to get to this point and I enjoyed the 3.0 8V engine with its vices and virtues and although I expected the 16V engine to be better I never expected it would turn out that well. Somehow I expect even more performance with the new intercooler and larger IC pipes, but considering how the car makes me giggle already with the somewhat unperfect and restricted current intercooler set up it all feels a bit like being Alice following the rabbit down its hole...

 

[scam75]

Sounds like an absolute beast and it has all come together nicely for you, well done! Be interesting to hear your findings on the IC upgrade, I would imagine you'd be in a position where you have all the power you would ever need in a 944 chassis, and more would be pointless. You must be north of 400BHP?

I once had over 300BHP in a Mk4 Escort RS Turbo, with a 2.1 ZVH conversion at the heart of things. It was insane and undriveable unless you turned the boost down, front wheel drive right enough and torque steered all over the place, would light up the tyres in 5th in the dry. About 200-250 would have been more sensible. On another Escort RS Turbo I had a 1.8 CVH and just over 200BHP, that was the better car to drive by miles.

Stuart

 

[TTM]

Thanks Stuart, as you know now it is great feeling to get satisfying results after all the effort made on an engine (re)build.

According to the injector output I should be around 500hp. The chassis is dealing with it well I think, but I have found it is all about finding the right adjustment on the dampers - too stiff is a no-no as it may not allow the chassis to "absorb" the performance of the engine. I do not really feel safe flooring the throttle before the car has well "landed" on its suspension, and you can believe me that with that sort of power roads that once felt flat and smooth suddenly reveal bumps you never thought existed, with the car almost literally jumping from one to the next! It's borderline overwhelming, or I may just be getting old [8D]

Some compliance remains needed on a road car. Running KW V3 dampers with the porsche968uk settings, they work well for me.

 

[TTM]

The new intercooler is in, with larger piping and a new large air filter. Very pleased with the results. As for how the car drives, well... it's a bit of a handful... honestly I feel a bit like Clarkson when he was reviewing the Ferrari F12 in Top Gear - the engine makes the car feel like it cannot handle all the performance, and that's great - it's ridiculous. I knew the 16V engine would be a significant step up but I did not expect it to be that good. Happy days!

 

[graham.webb]

Like the strut brace. Can you tell me what make it is...and, an easy fit over the cam cover etc?

Thanks

 

[scam75]

Awesome work Thom! Don't be throwing it into a hedge now...........must be insane. Enjoy.

Stuart

 

[TTM]

Thanks Stuart, I will do my best. For sure it would be a real shame to crash it after all the efforts made, but these days the satisfaction of getting the project to this stage prevails over the need to drive it like I stole it, so at least the risk of an accident caused by my fault is probably lower than ever before. Fingers crossed.

 

[Eldavo]

How much boost are you running now?

 

[TTM]

Boost settings must be reviewed with the larger and less restrictive inlet path and I did not have the time for it yet. Ultimately I would like to run 23 psi, but I suspect that will be too much for my limited driving skills.

 

[TTM]

Just a note on intercooler sizing - the cross sectional area of the new intercooler is ~1.65 times the one of the standard intercooler, which suggests it should flow ~65% more, in fact certainly more considering its fins are larger and make for a less coarse core than the std intercooler. Intercooler pipes and the Audi RS2 throttle body are 2.5", which is a tad above the total inlet valve area, so from a theoretical point of view there is not much bottleneck left between the air filter and the inlet valves, and it shows in how the engine picks up speed smoothly in the higher gears at lower rpm whilst feathering the throttle and how it is eager to rev beyond 7000 rpm with the throttle not even completely open. It seems there is as much air velocity under vacuum at low throttle openings as high flow when the levee breaks []

Packaging and lack of room are the main reasons why I did not go for larger IC piping and a larger throttle body. I confess I always found the look of the Audi RS2 throttle body very neat and I am sure that its mechanical features purposed for smoother fuel cuts and throttle tip-ins help as much on my larger engine as they do on the original 2.2L Audi engine.

 

[TTM]

I have set the boost to 23 psi. I tried even more but even though the engine seems happy with it the rear tyres aren't - at 23 psi already they feel on the edge of traction all the way through 4th gear up to 120 mph, and this should take a while getting used to. I still have the option of softening the ignition profile to run more boost and I will try but at this stage any extra gain in performance may feel redundant as the whole car feels fast enough due to having left the dampers adjusted to road-friendly settings. Even "big black" brakes take a proper beating as the car has never approached corners so fast ever before.

The custom intercooler works wonders as I see a rise of only 12°C above ambient temperature going full load through the gears up to the end of 4th gear.

Some nerd figures :

100-150 kph in 2.5s

100-200 kph in 6s

The peak injector duty cycle observed in the logs is 80%, still with 1200cc units. For what they are worth online calculatiors suggest a peak power of between 550 and 600 hp... [8D]

Oil pressure & temp and coolant temp are as good as on a standard engine, and oil consumption has been nil since disconnecting the crankcase breather from the compressor inlet. Happy days and it will be interesting to see how the denser air of the colder season affects performance.

 

[scam75]

Above my pay grade, but I reckon it must be fast!

i get peak boost in 5th of about 23psi before it drops to about 21psi (MBC), and those 8 valves and 2.5 litres are not hanging about at that point, god knows what yours must be like........

I must add that I spoke to LR, whose chips I've got, and they say that fueling is fine on their chips at that boost level using 99 ron super. I still have standard injectors, albeit recently cleaned and serviced, and my AFR's are low 11's at WOT @ 23psi. So all seems good.

Stuart

 

[TTM]

The car behaved very well during my Summer holidays and drove about 3,000 trouble-free miles. It runs like swiss clockwork and has drunk perhaps 2mm of oil on the dipstick, which is basically nothing considering how hard I ran it on the German Autobahn, though I did not feel confident pushing it beyond ~170 mph because of slight vibrations in the rear axle, partly caused by rear wheels out of balance (which is fixed now) and partly probably because the dampers seem on their way out - at 65k miles the KW V3 probably need a rebuild and they do not seem to dampen as well anymore as they should. I let my friend Sly (mentioned earlier in this topic) drive the car and said his was doing the same with about the same mileage... after driving the car he admitted I was right when I reckoned the 3L 16V turbo engine was a whole new world, which he had strong doubts about, and he added the only thing he didn't like about my car was that it wasn't his... []

Next project is to have the sills done as they are getting rusty, and perhaps have the whole car repainted depending on the quotes I will be getting.

Happy days.

 

[scam75]

Excellent work!