Krizzie's white 900 Aero

[Jon1]

The issue that I have with the engine sitting too high is that DIC cassette touches the underside of my hood on a couple of my cars with the stock motor mount. Good luck with RBM.

[hutch]

If you don't mind, I am curious what your thoughts are on the Type 8 primaries? Ive been mildly considering the swap on my SPG (stock 7's currently) for a little longer gears as I have gotten used to driving 9-3 transmissions but am always curious to hear feedback on them. What made you go 9, then down to 8.5?

And yes agreed with the engine sitting too high, my cars with stock motor mounts started to rub that corner of the DIC down, nothing a little filing won't take care of but something to think about.

I am also certainly no expert on the subject but I did not love the off-boost performance of the 2.1 head/intake combo, to me it was a mod in the 'dark days' of tuning c900s where you just tuned for high boost pressure and hoped LH could dump in enough fuel. Now with T5 control I'd be much more interested in higher compression and lower peak boost for better all around power. But, like I said, I am certainly no authority on the subject...

[Krizzie]

When I went for T5.5 I had type 7's which were nice for the LUCAS system and APC control. But felt a bit short when going to T5. Then I went to type 8's which made it feel like the 7's without T5. But on longer cruises I still found the rpm a bit high (we have highways which are rated at 130kph, so cruising is usually a little higher than that. )

Then the type 9's came out which are around a 450rpm drop in 5th (with later style diff) compared to the 8's.

Here's a vid I did with them.
https://youtu.be/qncfUXRiKHE

I had a lot of mixed feelings when I first drove with the 9's. The pro's were the rpm drop while cruising in 5th and 1st and 2nd gear that were actually worth something.
On the other hand they were very noisy, the triplex chains and my solid front mount made it sound like a supercharger almost the whole time. Especially on lower speeds when there is less wind and tire noise
The lack of downlow torque made quick take overs to need downshifs. Cruising at 100kph in 5th and "flooring" it would result in protest from the engine. Which wasn't a problem with the type 8's.

The big problem was that after 1200kms or so the chains started to slip.. (turned out the chains are too long for the tensioner to work with) I'm still waiting on the verdict of RBM, but I doubt they will admit that that is the problem and it was to blame on bad installation.

I then had contact with Jörgen Eriksson for a 8.5kit which was easier to source than a type 8 and basically cost the same, besides they were new instead of 30 years old and with miles on them. Also Jörgen was very helpful and kind in trouble shooting the problems I had with the type 9's
Long story short, I should've gone for the 8.5's from the get go.
They are just a little longer in ratio than the type 8's but the chains are a lot tighter so the engine and gearbox feel like they are directly connected instead of that jerkiness you usually have. Also they are a lot quieter due to the original offset 3 chain design.


On the 2.1 head matter. I just picked it up from the rebuilder, it will be installed next week, right in time for Intsaab which is here in the Netherlands this year.
The offboost drop in power should be minimal since it has been shaved to almost max tolerance so the compression drop should be minimal. If it's noticeable I might be able to play with the ignition timings to regain some power back. :)

[Krizzie]

2.1 head and intake are on. First impressions are good! No noticable difference offboost, but (coming) onboost the turbo feels a lot more responsive. Especially when you're cruising at say 2500rpms and you press the throttle it will boost almost immediately instead of holding for a second at 0 bar.

Some nice pics