camlob

Hi M - Yeah that crossed my mind but remember I didnt have the faintest idea that my cr's were bad. At 65k kms, I really thought my engine was fresh! In hindsight, yes it would have been maybe just as expensive, with better quality work by Colin.

I really wanted Colin's engine and he sent me an email explaining the work that was done to it. I was hoping for my investments to work out but it didnt and will probably bear fruit 1Q next year.

Colin's billet heads I can say are very very tempting. Maybe I should stop watching the black RSR vids!

camlob

Ken - Thanks for the condolences! LOL....

camlob

Thanks Colin. What is the purpose of the manifold on top of the ITBs on the pic that you posted? I know some RSR have some sort of manifold too.

Since they are doing construction work in the shop, and my parts are on the way, will it be safe for me to drive the car? They want me to take home the car. AFRs are off by 1.7 at times. My mechanic doesnt want me to use the car. My point is, even when it was stock, the cylinders were already off-balanced. And I was driving it hard. So now its tuned better than stock.

Will it be safe to use it once in a while?

evoderby

Wow Colin, great input on this thread.....I know there's some massive £££'s worth in R&D on your part behind reaching conclusions like the ones you're now sharing for the greater benefit of the community.

On the part of cutting windage losses, a very nice and easy set up to achieve this is a system I first read about in David Vizard's Tuning the A-Series Engine AKA "The Yellow Bible".

It's called a 'sump evacuation system' and basically links various crankcase breathers directly into the exhaust stream by means of a one way valve. DV's testing showed a crankcase VACUUM of several psi is possible with the right sealing applied, worth around 2% on the dyno, and at the time heavily used in NASCAR.

I have fitted a kit by Moroso on my Cooper S, as said very easy.....I'd have to say when running Cats on more modern Porsche applications it might be a good idea to link into the exhaust after the cats;-)

Here's a link: http://www.moroso.com/catalog/catego...?catcode=13023

NineMeister

Adding plenums on top of throttle bodies can also improve performance, but in this case the only reason for the boxes is noise reduction.

evoderby

Colin,

The dyno graphs you've posted show a marked dip between 2.5-3K RPM, I don't see any real significant differences (negative ones that is) further up the rev range when running ITB's....

....question is whether in real life you'd be running WOT @ 2.5K , I think not. Small throttle openings is what driveability in this area is all about......

Although the dyno gives an indication, could you perhaps share some thoughts on this...

NineMeister

You're right that the dyno gives an indication, however the reality is that the torque response of the plenum engine with standard cams is definitely better than the ITB engine in this region. That said, I now own a G50 Carrera 3.2 Coupe with a 993 engine in the back and the first modifications I intend to do are to fit Motec, SSI's (or similar) and a set of ITB's.....

camlob

Pheeew....couldnt even drive the car home. The rings gave way while in the shop. According to the mechanic, it made a noise that he thinks is the rings. So they are putting it in a flatbed to bring it to my house. Numbness again is hitting me. LOL....

Well it will take two weeks for the parts to get here. And two weeks for the construction work in the shop. So Ill just stare at her while she's home.

Macca

Damn. Sounds serious. Lets hope the valve train is ok.

I really hope your luck turns.

Nothing worse than a project that goes into $$$ orbit and not give the expected returns.

Its lovely looking at the 993 even when its not moving! It will give you time to strat playing with some of those other upgrades and cosmetics you were planning....

Best of luck.

Cheers

NineMeister

You must get the engine stripped and inspected before you let your mechanic loose with your boxes of new expensive parts. Why?

I've just checked the spec on those DC43 cams and it looks like they have 3-4mm of lift at TDC. The maximum overlap lift that you can run on a stock 993 engine is around 2mm, so first of all did the shop machine the stock pistons for clearance?

Secondly, the peak lift is 12.5mm. Did the shop also check the clearance between the valve spring retainer and the valve stem seal at full lift? From memory the stock clearance is in the order of 12-12.5mm and I know that when we fit the 9m Sports camshafts we have to shorten the valve guide to achieve an acceptable clearance.

Finally, if the engine has only done 60,000km there is no way that the bores are that badly worn that the engine will smoke, therefore the only cause of a problem is damage to the piston, bore or ring. Most likely scenario is broken rings due to detonation, which may have occurred when mapping the engine on the dyno.....

All I am saying is that you have to be sure that you know what you are letting yourself in for and do not accept any line of bulls**t that is covering up the likely fact that someone other than yourself wrecked parts of your engine (In my opinion - for what it's worth).

I will apologise in advance that I will be away for the next 4 days so will not be able to come back to you on this until Tuesday night, however maybe Steve or Geoffrey can back up my thoughts whilst I'm away to help you make the right decisions to move forward?

Macca

Hi Colin/Camlob. Just a foot note as Jap Import cars make up 73% of our used car market here.

We have alot of Japanese import 911s in our country as they are often cheap. Ive imported Porsches privately myself from Singapore (993RS + 996.1 GT3) and Japan (968 6spd).

Unless you have the original service manuals on the vehicle dont assume its travelled only 65k km!

Infact with Japanese imported 964/993 cars assume no deferred maintenance and odo replacement (common failure gearwheel) or clocking (common export practice to reduce Kms) as the rule if you are doing heavy mods unless you have firm evidence otherwise!

Good 6spd 993s dont turn up in the auction network very often at all. Sometimes they do if they are the RHD variants which are less desirable.

A friend who is a Lisenced car importer helped me with the 968 as it was my first experience importing from Japan. It wasnt high miles maybe 70k km for a 1993 model. I got some paperwork not much. He encouraged me to trat it like an unknown quanity as I was putting it on the track from tie to time as well as Daily Driver. I did the belts, plugs, leads, dissy and everything. It ran real strong while I had it and only blew a hoe on track (my mechanic had not fastened properly) and a clutch down country (shattered it asfter a hard track day - was the original too as we found out so I suspect the miles were right)....was lucky.

Because this is you first 993, and because you only just recieved it from Japan auction when you started the modification 7 months ago - you need the view the history of the drive train as an unknown quantity to some degree and I think be slow and methodical at having everything torn down and checked closely as you say.

Heck. Send it to Colin and get a real engine built ;-)

Cheers

Macca

Hi All,

My tuning was finally finished. LINK Xtreme G4 (Vipec V88) with Bosch Red Devil 36lb injectors. Dach X catless pipes, RSR mufflers, MSDS Cone filter. Using MAP sensor and custom fabricated inlet tube. Cams are 993SS.

The final run chart below was done in a warm (33 Celcius) Dyno environment as it was the end of a day of dyno tuning and the room had got pretty warm. The tuner pulled back a bit on hitting peak numbers in favour of driveability. Theres still a few more horses and lbft on the table (with a further 2-3 hrs of dyno tuning )but first they want me to test drive the vehicle and see how i like it. The car was tuned on teh road as well and there is no stalling and the throttle response is apparently very very good. I havent driven the car yet but will do at the end of next month and then make any final changes from there.

Below graphs show the final run compared with the stock unmodified engine.

Runs were done on Dynapack 5000 hub dyno by the same croud that have been doing the (5) dyno sessions on this car over the last 12 months. They are also LINK agents and expert installers and tuners although they mainly work on ralley cars and this is the first Porsche LINk install they have conducted.

Charts show actual Rear Wheel outputs. You can dream up and apply any TCF correction mark ups you like.....if you are really optomistic this is a 320 bhp engine now LOL!

Peak RW Power - 274 PS @ 6000 rpm
Peak RW Torque - 240 Lbft @ 5750 rpm

So in the final analysis it appears the Cams made very little difference overal but the aftermarket ECU like Motec with injectors and freer flowing exhaust makes 10% more poer and torque than stock factory figures. This seems consistent with threads Ive read by Colin and others on Motec 993 NVR engines.

evoderby

Hi Macca, since the only printouts I see are of stock vs. 'complete modification pack' how did you reach the conclusion that your cams add no power and all gains can be attributed to programmable Ecu/uprated injectors/exhaust?

Transmission losses for hub dyno's (great tool BTW!) are often quoted around 10%....which would take your standard 247-248 @ Hubs to 274 PS. Pretty much spot on!

At 274 @ Hubs in modified form this 10% loss means around 304 PS @ flywheel (or 300 HP)

I know the history behind you moving towards programmable ECU, although I'm sure your engine is running great I feel given the investments you've made the gain vs. stock+chip+exhaust is very minimal.

I don't know what Colin sees on the 993's but 964's on Motec with stock cams do 315-320 HP, with cams 345 HP.

Are you sure your cams are timed correctly? What sort of ignition curve are you running.....is it overly safe (how much advance do you run @ max load / 5.5K + RPM)??

Both of these can leave a lot of power lying on the table....

camlob

What nos do 997 GT3's mk1 churn out in that dyno?

Evoderby - You are probably right about the cam timing if indeed 350hp is achievable. Yeah the 350hp with cams and motec IMO maybe can only be done by Colin or Geoffrey! Might be the combination of cam timing and motec tuning. I recall Colin did 10 hrs in one of his cars.

Correct me if I am wrong, but to adjust cam timing you have to pull the engine down. Unlike other cars where you can play around with it while still in the dyno.

I just used the timing specs given by John D. and probably thats what Macca did.

camlob

Well some parts arrived.

Wevo blue engine mounts and poly trans mounts from EBS. Any inputs on the poly trans mounts? They seem pretty hard! Got some tarret drop links from a member over here. Brand new and it came at a "gotta have it" price!



And some stuff for my butt....