Engine build progress

[Diver944]

When you've got a 3L all tuned up and running properly with dollops of torque across a wide rev range I really don't think you'd need a closer ratio box. Certainly with mine it feels like the 5 speed Turbo box is already very closesly spaced. Any closer and you'll be changing gear all the time

 

[nick_968]

ORIGINAL: TTM Nick, looking forward to hearing positive results with the new headers. I suppose you have 944S2/968 oil thermostat housing fitted with the 968 oil cooler? Or did you modify the lines?

Thom I took the 944 oil thermostat housing off my 3.0 8v engine (the one in the car) and replaced it with the housing from my original lines and bought a used set of 968 oil lines plus a new 968 oil cooler. What I think happened is when my engine was built it was put together away from the car and when it turned up to be installed they probably realised that the lines on my 968 did not fit on to the 944 housing that has been used in the build and changed my oil cooler and lines out instead for a used 951 cooler, but never consulted with me on this, I also never saw my 968 cooler and lines again which together cost over £500 to replace. Trouble is there was no duct fitted to the 951 oil cooler, it was also in very bad shape - totally blocked up fins and badly corroded so probably doing next to no cooling. Took me a while to notice as I had never taken a close look at my 968 oil cooler before. The 968 block is a lot more reliant on oil cooling as I believe the water cooling in the block does not run as low down the bores, hence the oil cooling piston squirters and modified oil cooler.

 

[nick_968]

ORIGINAL: MarkK Is the 968 gearbox more delicate?Deffo feels more lightly built to me?Can it take big power?

968 box is definately not more delicate than a 951 box although I don't think the gears are hardened none of the people I know running big power on them have issues but I have heard of issues with the 951 box once the torque is too high and they are used hard on track.

 

[nick_968]

Thom, there were two version of the 968 TRS box, standard one has the same ratios as the 968 and same final drive. The other one has everything the same but a shorter 5th and 6th. There is a guy here in the UK that sold the black 968 turbo RS - Bubbles but had a load of the spare parts that came with it that he was selling which included 2 spare original boxes. When I enquired he could not tell me which ratios it had and I did a lot of digging. When I found out it had the same ratios as my original 968 box I decided it was not worth the money at the time just for the benefit of a factory LSD, and also the risk of getting one of the ones with shorter 5th and 6th which I did not want. What I really wanted was a 968 turbo S box.

 

[TTM]

Yes Nick I got in touch too with him with regards to the gearboxes he was selling, you and I we discussed it at the time if I remember correctly. Now that you are likely to solve your spooling issue with the new headers, I will sure be interested to hear if you still think the standard 968 NA gearing is too short for a 3.0T engine. To be honest I have been looking at gearbox options again lately as I think the torque on my engine has put the gearbox bearings on their last legs [8|] In case you didn't already know but I'm sure you do, the factory 968TRS cars did use a twin oil cooler set up that can be replicated by adding the additional cooler from the Tiptronic cars, located on the left side.

 

[nick_968]

Thom, I think my car will still be slow to spool. Only when I go to a turbo with a nr8 hotside will I be able to answer this properly. Re the twin oil coolers I did not know this. Is the tiptronic oil cooler the same size as the 968 oil cooler? Do you have any pictures of this installation?

 

[DivineE]

ORIGINAL: Diver944 When you've got a 3L all tuned up and running properly with dollops of torque across a wide rev range I really don't think you'd need a closer ratio box. Certainly with mine it feels like the 5 speed Turbo box is already very closesly spaced. Any closer and you'll be changing gear all the time

I second this vote. I kept running out of gears and reaching for 6th in my 3.2, or thinking I was in 3rd not 5th. I definitely wasn't looking for shorter ratios.

 

[333pg333]

Without wanting to sound like Capt. Obvious, the gearing is totally related to where and how you drive the car. Most of you might have seen my friend's video taken on the track last week with a new 3L S2 16v turbo motor in his 1986 951. He has a stock 951 gearbox with the Ring and Pinion from the S2. This makes the gearing noticeably shorter (and a lot more usable for 85% of most 951 owners IMHO) but most people would suggest that it's way to short for his car on the track. Not so. Of course there are probably always better ratios to be had after long and expensive testing, but for him it seems to work very well. If you hadn't seen it yet: http://www.youtube.com/watch?v=HkC4n8TqkYA

 

[TTM]

ORIGINAL: DivineE I second this vote. I kept running out of gears and reaching for 6th in my 3.2, or thinking I was in 3rd not 5th. I definitely wasn't looking for shorter ratios.

A "problem" with a 3.0+T engine and the turbo gearing is that the gap between 4th and 5th is too small when there is so much torque available. The S2 gearbox uses a longer 5th gearset and in my experience with my S2 I feel that the S2's 5th would work well in a turbo gearbox as the wider gap is I think very manageable. Far earlier in this thread Jarmo mentioned he uses an S2 5th gearset in his turbo gearbox, which I'm sure would help a bit with a high capacity engine.

 

[TTM]

Just thought I would post a quick update. So my 3.0 engine now sports a full Lindsey Racing 3" exhaust, and it's back with a standard turbo camshaft as a particularly annoying and persistant issue that seems to be too low oil pressure in the camshaft housing damaged the 9R (late standard 944 NA 8V) camshaft and some lifters. For various reasons I haven't had the chance to drive it much and retune it - and a coupler of the intercooler is leaking somewhere when under boost - but I can say that the exhaust should allow, expectedly, dramatic performance gains. The engine feels already more responsive when lightly opening the throttle, and it's not a placebo effect. The sound though is a pain in the arse. I went with the intermediate resonator and a Magnaflow rear muffler and though it sure sounds quite "hairy-chested" from the outside, I can't get to grip with the deep roar inside (which I must admit reasonably clears up at motorway speeds), and on anything slower than A roads I feel like driving a souped up Honda Civic. Just need a baseball cap, a loud dump valve and some Rap in the CD player to complete the picture. A loud exhaust only highlights the fact that a turbocharged, 8 valve, in-line 4 cylinder engine is probably the worst-sounding engine configuration one could think of. In my opinion at least. I purchased a "special" muffler with should quieten it all down, just have to find the time to put it on. Even though I haven't figured out why lifters are so noisy when the engine idles, I'm well pleased to be able to drive this car again [] As for Sly he has begun building a 3.0 16V turbo engine out of a 968 lump. If anyone is interested in his current 2.5 engine, it is for sale, and it is still going very strong! Here is a pic showing how my engine looks like at the moment.

 

[Jonny944CS]

A very tidy looking engine Thom. [8D] Does the cam-carrier or cylinder head have a one-way 'check' valve fitted in the oil supply drilling... Could this be blocked?

 

[944Scott]

My wife has a magnaflow on her 2.8 Z3 and has had exactly the same issues as you describe, In the end we had some db killers fitted to reduce the noise.

 

[JarmoL]

Hi I got an extra lindsey 3" exhaust when I bought my car. I installed it at some point but couldn't bear the droning sound it made. I ended up cutting the stock end damper and welded it to lindsay 3". Sound was greatly reduced.. couldn't feel any difference in power. I was happy with the setup until MOT inspector deemed it illegal so I had to go to all original again.. I have to say the stock exhaust has it's positives too.. It's great if you are tracking your car, never a problem as it's always under 90 db.[]

 

[TTM]

Not sure if this thread is still of interest to people, but I still have some (minor) updates that might be of interest to some. As the exhaust was too loud for my liking I fitted a Varex muffler in place of the Magnaflow. It features an integrated valve controlled by a motor from and electric window mechanism. Activation is done manually with a small remote. I liked the concept as it is not just a valve that closes and prevents most of the gases to get out. When the valve is closed, gases go through the muffler in separated chambers. See the Varex website for a full description (not affiliated, btw). I chose an oval 3" unit, labeled VMK 11-300, which is the closest to a decent look I could find, and which allowed reusing the piping of the 3" Lindsey exhaust, tip included. When the valve is closed it sounds close to a standard turbo exhaust. Perhaps there is a subtle deep buzzing sound when cruising at motorway speeds, but it's far more tolerable than it was with the Magnaflow muffler. I may also be confusing the sound with a rear wheel bearing that might be on its way out. When the valve is open it is very reasonably loud - not as loud as a Magnaflow or a Dansk muffler but just the right level tolerable, loud enough to provide aural enjoyment without being LOUD to the point of being a pain on long distances. I actually now drive with the windows slightly opened to enjoy the sound more, whereas I almost wanted to wear earplugs with the Magnaflow muffler. I had mostly civic motives to install such a muffler, as I don't like attracting attention, especially in my neighbourhood, and I was much pleased to notice that the dB level reduced to the point of passing the legal test - a sound level meter positioned 45° and 40" off the exhaust tip measured 86 dB with the valve closed (and 95 db with the valve open), with the engine revved up to 4500 rpm, the maximum official tolerated level for a 1990 944T being 91 dB. All in all a great buy, a bit costly at €400 (shipping included from NZ) but a rather efficient add-on. I may even have the possibility to control valve activation with an output from my ECU, in function of engine load or whatever parameter I want. Just have to figure out which relays to use and how to plug them in... [8D]

 

[944Turbo]

Yep still interested, thanks for the update! interesting stuff

 

[George Elliott]

Interested? - very interested Thanks for update George 944t I had similar experience with 2.5L and 3" DP and exhaust. Far too noisy. I fitted a Jetex 3" straight thru back box and its lovely now. Perhaps a 3L is different, plus I'm sitting on the opposite side to the tailpipe, so the risk of ear damage is less[] Its nice to overtake silently[] - sometimes I think other drivers do not like being wakened suddenly.

 

[Diver944]

How on earth did you find out about that Thom? Great find though - pics please []

 

[TTM]

Paul, you wouldn't believe the things you could find on the Internet [] Here is a picture. It hangs a bit lower than a standard muffler but I haven't heard it rub on the ground yet.

 

[333pg333]

That's funny that you mention this Thom. A lot of the kids driving the loud modified Japanese cars are fitting these items to them. The idea being that when they get pulled over by the cops they just flick the switch and 'hey presto' quiet car. What's even funnier is that the cops are onto this and can spot them from behind the car. Then they tell the kid to switch it over and 'hey presto' they get wisked off to an inspection station where they invariably get defect fines. Some of them are quite costly too. Having said that, I appreciate that you did it for valid reasons and am glad to hear that you're happy with the outcome. []

 

[os951]

We have planned to use this with junior's new exhaust system.