996.1 cab C2 manual

[Jamesx19]

Long old process, but you don't want to be be experimenting with the supposedly finished article I guess!

At least when its all tested and proved out, then you will have a strong and safe unit that produces the goods..... at high revs...

From what your saying, the exhaust side is still where the restriction is? I haven't looked at Mikes last "benchrace" post for a while. Will have another read of that when I get the chance.

Cheers

 

[Dammit]

It's more that the exhaust (specifically the manifolds) has to match the characteristics of the rest of the engine in order for it all to perform as expected - primary length and diameter are critical.

It'd still work with other manifolds, but there'd be a certain amount of performance left on the table as it were. Which I'd find very difficult, if not impossible to accept. Other points of view are available!

 

[Jamesx19]

But for a ha'porth of tar!

Definitely worth it....

 

[Shalmaneser]

It's ticking along, rather more slowly than we had anticipated but then it's very much something that has to fit around everything else, it that makes sense?

Latest is that we're finalising the ITB actuator design so that it can run with a Porsche electronic throttle and a cable so that it's (as close as is practicable) to being a drop-in for these cars.

Once that's done we'll fit it to one of the cars and validate that we've thought of everything in terms of vacuum for the brake booster, AOS and so forth.

We need our slot at the machining place to come up for some tappet chests to be made with the new (smaller base-circle) cams in mind (oiling, tappet barrel dimensions and so on needs to change), then we need the cams themselves, and finally we need the exhaust manifolds. That *should* be the engines able to be assembled, which leaves us with the gearboxes on the to-do list. Oh, and mapping the engines on the Dyno before loading them into the cars.

I thought itbs were out of scope for this project? Very exciting if they're getting developed!

 

[Dammit]

They were always high on the list for me - whilst (like many, I suspect) I love a good "pub metric", so have always had a horsepower goal it's been very much second fiddle to how the car feels.

And that, for me anyway, is not just feeling the throttle response but also hearing it - that angry, instant "brap" when you are downshifting, and then as you come out of the corner the bellow that tightens into a howl before finishing as a scream.

I'll also admit that the 8,000 rpm goal was at least in part because a flat six at 8,000 RPM with a decent exhaust should sound incredible, and the induction howl from ITB's will play a big part in that.

We're going to test them, then they'll be offered on https://www.h2-engineering.co.uk

One word of warning though - on an otherwise stock engine I've got no idea what they'd do power wise, Wayne Schofield of Chip Wizards says that when he's tried ITB's an on M96 before they were always outperformed by the stock intake. But, the noise. The noise

 

[Dammit]

Oh, I actually came here to post a question:

My car's in for a service on Monday, along with it's MOT.

It's done (to my shame, although Covid gets an honourable mention) ~600 miles since it was serviced last year.

I was going to ask for an oil change - what else would/could it need?

 

[deMort]

If it's just booked in for an oil and filter then hopefully the garage will do a free VHC .. that's a pretty good look over for no cost .

If it's in for an actual annual / minor service then everything will be checked .. you wont get tyre pressures or lvls topped up on a VHC though.

MOT is a basic min safety test so only items close to a fail will be reported .

 

[Shalmaneser]

They were always high on the list for me - whilst (like many, I suspect) I love a good "pub metric", so have always had a horsepower goal it's been very much second fiddle to how the car feels.

And that, for me anyway, is not just feeling the throttle response but also hearing it - that angry, instant "brap" when you are downshifting, and then as you come out of the corner the bellow that tightens into a howl before finishing as a scream.

I'll also admit that the 8,000 rpm goal was at least in part because a flat six at 8,000 RPM with a decent exhaust should sound incredible, and the induction howl from ITB's will play a big part in that.

We're going to test them, then they'll be offered on https://www.h2-engineering.co.uk

One word of warning though - on an otherwise stock engine I've got no idea what they'd do power wise, Wayne Schofield of Chip Wizards says that when he's tried ITB's an on M96 before they were always outperformed by the stock intake. But, the noise. The noise

Understood. For me and I'm sure many people one of the best things about the internal combustion engine is the noise - something we see less and less of even with modern ICE cars.

I'm sure the harmonic supercharging effect Porsche very cleverly engineer into their plenums will be lost somewhat but I wonder if their might be gains to had in throttle response. I for one would love a set, I work in design engineering so I've often toyed with designing an adaptor for some BMW throttle bodies off an m-car. Running the engine would prove to be tricky though, I'm sure one would be forced to go standalone which ups the cost and complexity. All for marginal gains as you say on a standard motor...

Can't wait to see the results of your development!

 

[Dammit]

That depends- you could enclose the ITB trumpets in an airbox that has a MAF at the inlet- which would give the stock management what it needs. I can't imagine that the standard map would be that happy about it, although I honestly don't know what it would do. But I'd certainly look at a mapping session as a requirement.

 

[Shalmaneser]

That depends- you could enclose the ITB trumpets in an airbox that has a MAF at the inlet- which would give the stock management what it needs. I can't imagine that the standard map would be that happy about it, although I honestly don't know what it would do. But I'd certainly look at a mapping session as a requirement.

It has crossed my mind - both my E46 and E36 ran itbs with mafs but I imagine that the stock ECU would never be truly happy with things and I'm sure there would be driveability compromises that could only really be fixed with aftermarket management.

The 5.2.2 ecu does run quite nicely with the maf unplugged so I wonder if the limp home map could be altered to give 'Alpha N' style management ie. running off the throttle angle only but again I'm sure it would be a big compromise.

There is also the concern with maintaining the partial vacuum in the crankcase, I know that this can be a problem for itbs and I've looked into vacuum pumps for this but it certainly adds complexity. Anyway enough dreaming, pics of your development work when you can please!

 

[Dammit]

Fascinating MOT update - my 23 year old car needed a number plate bulb, then passed with no advisories.

 

[Ghianightmare]

Great result! one question though, apart from the passenger seat and the body, is there any other part on your car that is 23 years old? :wink:

 

[Dammit]

Fewer with each passing month I think.

On which note - picking the car up from it's MOT and taking it back to Auto Audio (where it has lived for much of this year) involved quite a lot of cruising on the motorway, which reminded me that when doing such driving I like resting my elbows on the (left) centre console cubby lid and (right) door bin lid, and I always find the lack of padding on the right hand side a pain (literally, the bony knob of my elbow doesn't like it).

I've asked Auto Audio to take the leather off, fit a thin layer of dense foam and recover with some fresh but matching leather.

 

[infrasilver]

I did this to mine when I first got it as I thought the elbow rest was far too uncomfortable. I peeled back the leather and glued a 5mm layer of foam under it before sticking it back, it has been a godsend for the last decade.

 

[Dammit]

Got the car back, have a terrible iPhone snap until I can take some decent photographs.