ALEX P

Quick update - Got the engine started and given it a bit of a run in. Also finished putting bumpers etc so car is getting there.

Pictures by ALEX-P76 - Photobucket

It's not ticking over very well and is very jittery at low rpm but seems fine when it gets to around 2750rpm and beyond. As well as this it is running very rich which leads me to believe that it could be a vacuum problem. I don't think there are any leaks but it is possible that a pipe is incorrect.

Vacuum lines are a real nightmare as they seem to change from early to late 964's, tiptronic, C2 or C4 so it's really confusing. I've been through PET and the workshop manual and have a diagram for a VRAM system but was wondering if anyone had a good diagram of some good photos or an early 964 engine's vacuum lines?

ALEX P

Finally traced the running problem back to being a sticking air flow sensor that wouldn't fully close due to the barn door picking up on one edge. This made the car run very rich and wouldn't idle. When the air flow sensor was freed off, the engine ran as it should but I changed the oil pretty soon after as I think it had fuel contamination - when I changed it you could smell petrol mixed in with it.

I've now done around 1200 run in miles starting off making sure not to load the engine, keep the RPM right down & lots of downhill decelleration runs and varying the RPM. I could feel the engine loosen up after this run in period and it has now gone back to the engine builder to retorque the headstuds & adjust the tappetts and have a general checkover.

Can't wait to get the car back next week so I can really see what the engine feels like further up the rev range, the one thing I immediately noticed is the low down torque improvement, it just picks up in any gear - puts a smile on my face every time

ALEX P

I've not posted on here for a while but my rebuilt engine is now nicely run-in.

Finally got round to making the exhaust for it. I bought a 14" Magnaflow silencer, a couple of flanges, 4 x 90 degree bends and a length of stainless pipe and set about measuring, cutting, grinding and got a friend to do the welding as it wouldn't have looked too pretty if I had done it!!

Few poor quality pics below but it has transformed the car and feels like it can breath properly now. I'm really happy with the sound and the price of the parts was a fraction of what an off the shelf equivalent would have been.

christallon

Hi Alex,

Your exhaust looks great, and by the sounds of it, you are quite happy!!! Well done. Are you willing to share the build specs with measurments (if you kept them) with you Rennlist Brothers here? TIA. Love your hutspa!!!

Chris

ALEX P

Hey Chris, no secrets about my build specs, if I have the information then I'll openly share it (apart from cost in case the wife is watching!!).

Current engine spec is as below - If there is any specific spec or measurement that you would like to know, please ask.

Modified / Flowed case
Modified / Mooned standard cylinders
Supertec Head Studs
ARP rod bolts on weight matched standard rods
JE Pistons RS (to suit 993RS valve size)
Patrick Motorsport flywheel
Sachs sport clutch
993 RS Inlet Valves (8mm shaft)
993 Standard Exhaust Valves (8mm shaft)
Race springs with titanium retainers
DC21 cams with 114 deg lobes
Head inlets lightly ported
Autothority Hotwire MAF (stock chip for now.....)
1.750" dia Headers
Custom 2-in 2-out with 14” Magnaflow Xflow rear box (11386)
Lightweight fibreglass tinware
Rebuilt distributor (new belt)
Single alternator pulley conversion
Balanced Crank/Flywheel/Pulley
Strengthened engine mount bar

KaiB

I'm interested in the fact that you chose 1 3/4" headers rather than 1 5/8" for this build.

If I remember correctly, Gamroth/Weiner will be using the narrower headers for my build this winter...if I'm not wrong, they have a reason for doing so and I'll have to ask.

Chris, when we do the RSR build (probably two winters from today, sadly, but I can't handle 370hp yet) the current tranny is yours should you want it, tehe, as I plan to go six speed.

ALEX P

Not too sure on that one Kai. I thought the 1.875" headers were for 3.6s and especially modified 3.6s. There may be something in what you say as after trawling through lots of threads on here I didn't bother going larger on the exhaust valves, just the inlet valves although I did sway to the lighter 993 8mm shaft.

I've pretty much come to the end of the engine build now save a few tidying jobs. I got the car onto the rollers yesterday for a remap and it went in there producing 263.8bhp and came out 308.2bhp so I was very happy. I've stuck a copy of the dyno sheet below.

KaiB

WAHOO!!!

Neat stuff....

NineMeister

Alex, nice engine, nice result, but you need Motec.

FeralComprehension

No doubt! Can we see the torque curve?

KaiB

Please...

ALEX P

Thanks - Motec is a nice thing to have but it's a whole lot of money when (arguably) there are equivalents at a fraction of the price that are (again, arguably) as good. Have you ever tried an ECU like the DTA S60?

I'd love to say yes but unfortunately I don't have it as the rpm pickup broke

Maybe next time there is a local group dyno day I'll go & get one when the engine has loosened up some more, sorry about that!

I know it can be worked out fairly easily but would have to check the maths

NineMeister

Alex,
The short answer is no, I've not tried a DTA, but the truth is that there is a lot more to purchasing an effective upgrade than the price of the box under the seat.

Wayne has the same Bosch dyno that I have, in fact his handset & pickups came from my dyno after I opted for a Dynostar electronics upgrade about 5 years ago, the rpm pickup was always an issue and one of the reasons why I upgraded my roller set. If you want a torque reading, call over anytime and I'll happily run your car up on the 9m rollers and show you a few comparisons to similar engine builds we have recorded.

evoderby

Hi Alex, nice build!

I Have experience running DTA S40 and can vouch for the quality....DTA S80 would be more suitable for a 6 cilinder application than the S60 and costs around £950. I think Motec costs around £ 1500.

This however is only the start, you need a custom loom made up, larger injectors, a base map to get the car running ( without ruining it) and than do the mapping.....lots of it. WOT / max power is almost the easy part. Cold start, idle, temp compensation tables, transients etc....which takes loads of dyno/road mapping to get to a good level.

This is where it really pays off having someone who already went through the learning curve, has a custom loom lying on the shelve, has suitable base maps etc.

This is where the difference in price between the ECU's can be easily won back by saving time/not having to go through a learning curve. That is unless you take a hobby approach and are willing to spend your own time and go through the learning curve yourself, rather than paying someone else to do so.

I'd be happy with the 308 HP for now, put £6 a day in your non- smoking piggy bank and go for the 40 HP ECU package in 2.5 years time;-)

ALEX P

Absolutely, I couldn't agree more.

That's very gererous of you, thank you very much. Unfortunately I'm not often up around that way but the next time I am I would love to call in and have a look round.