993 with GT3 upgrade - Dyno plots (for Maurice)

[jmspear]

My billet head upgrade from Ninemeister is finally finished and wow!

I was driving it without a remap (so mixture was a bit off) at Oulton on Saturday but it had a full remap yesterday and the result is:

GT3 Mk 1 power up to 6,000 rpm and slightly more Torque!!

It definitely feels fantastic on both the track and the road. One GT3 owner at Oulton came up and asked to look at my supercharger install, imagine his surprise when I lifted the lid to show a standard (looking) 3.6 non varioram motor.

The spec of the motor is:

1. 9m/4T billet cylinder heads
* high velocity intake port
* optimised combustion chamber for stock piston, reduced volume by 3cc, closer squish clearance to sides of piston
* 9m race valve spring/ti retainer set
2. 9m sport (hydraulic) cams
* similar cam to our 964 Motec +1 cam
3. Split flow 100 cell cats
* any silencer will work with these cats. In development on Robin's 993VR conversion we tried stock, Techart and Cargraphic silencers and they all made the same power on the day - my car is running a full cargraphic system from NGT extractor manifolds through to rear boxes, Robins car the Varioram 993 in the dyno plot is just running 100 cell cats with std heat exchangers and exhaust cans
4. Live remap.
John's car had a live remap in its previous guise with the sport cams and standard heads, but we ran out of time to do this before the track day. However we did manage to get the car on the rollers for a power test and to check the mixture throughout the rev range, where we found that it was running towards lean 3-5000rpm, ok 5-6000 and rich 6-7000. This was fixed with the remap on Tuesday and the plot is after the remap and optimisation!

The build was actually finished earlier in the week, but on testing the power was found to be down from expected. This was eventually traced to the 88,000 mile hydraulic followers, so rather than risk future problems we replaced the lot, hence why the car was only completed the day before the event.

As John mentioned, a selection of cars tested on the day were:

3.2 Carrera remapped = 242bhp
stock 993NVR engine in early race car on headers, 9m remap = 312bhp
stock 964RS = 275bhp
2 x 964RS with cat bypass & full remap = 305/309bhp
3 x 996GT3 mk1 = 364/375/390bhp (last one had exhaust mods)

Johns 993NVR (Non Vario Ram) = 352bhp with 317bhp at the tyre

Apologies if you have read my posts on Rennlist but wanted to share with PCGB members, I will be at many track days this year so plenty of chances to see it in action!!

Cheers

John[]

 

[jmspear]

Sorry, forgot to explain the colour coding on the dyno plot.

Blue = Std MK1 GT3
Red = 993 Varioram with Colins upgrade this is showing power in excess of 360BHP!!!
Green = My 993 non varioram.

 

[Sundeep]

any pics of the car John ?

 

[Gary Bullen]

ORIGINAL: jmspear

Sorry, forgot to explain the colour coding on the dyno plot.

Blue = Std MK1 GT3
Red = 993 Varioram with Colins upgrade this is showing power in excess of 360BHP!!!
Green = My 993 non varioram.

.....and lightly modified Mk1 GT3's are knocking out around 390bhp for probably less ££££'s than this mod. Only one arm and two legs required! Hope you don't share a track day with the Titanic/GT3 gang as your rear view mirror will probably be crowded.

GT3 RS's are typically over 400bhp. Allied to a fantatasic chassis the GT3 RS is, if well driven, hard to beat unless you are in a hairy Caterwestfieldical.

 

[paul howells]

Gary whats the problem,sounds like you are intimadated by a little oh 993.
sounds like good sport to have a mirror full of titanic/gt3 club drivers then!!
Are they fast?

 

[jmspear]

Gary - worried are we []

Least you will be in my rear view mirror (what was that warning sticker you see on rear view mirrors- things look closer than they really are !)

Won't get into a contest but last time I looked 993 C2's were (a lot) cheaper than GT3's and holding their own in the residuals stake []

Difference pays for lots of body parts!!

Even with the upgrade I wasn't comparing my car to the GT3 RS, that would not be fair, the 993 RS crowd do that to great effect! but I did compare it it to GT3 Mk1 and it compares very favourably with these cars and shocks the hell out of them on the straights - bearing in mind it looks like a std 993, is lighter and also has a suspension and brake upgrade as well, so can handle itself well in the twisty bits as well!

Anyway, I love my 993 for a variety of reasons (sound, quality of build, driving experience, looks) and that is why I have undertaken the upgrade, I love it even more now and it was a much better way for me to go than chopping it in for a Mk1 GT3 which was the alternative.

Let me know when the next Titanic GT3 day is and Robin (993 Varioram conversion) and I will come along for some fun []

John

Sundeep car pic is as follows:

 

[jmspear]

Just seen that Paul has already made the comparison from the 993 RS camp - bring it on, didn't notice any GT3's and plenty of them had Titanic stickers, doing anything special against the 993 RS guys at Oulton !!

Pic of the head:

Taken on my camera phone before the install

 

[jmspear]

side view

 

[Sundeep]

ORIGINAL: Gary Bullen
.....Hope you don't share a track day with the Titanic/GT3 gang as your rear view mirror will probably be crowded.

Gary I would have to agree !

John's rear view mirror car will be full of the Titanic/GT3 gang on such a track day.... but just the rear view mirror...... sounds like a fun track day for John ! []

and let me know about the next Titanic GT3 day as well as I'll like to see the 993 in action verses my tubby targa !

 

[LK_991GTS]

Thanks for the information. It sure is an impressive upgrade. []

 

[Gary Bullen]

ORIGINAL: jmspear

Gary - worried are we [] Quaking in me boots! Just joshing and I am sure the mods to this RS transform what is already a superb Porsche into something quite amazing. []

Least you will be in my rear view mirror (what was that warning sticker you see on rear view mirrors- things look closer than they really are !)

Let me know when the next Titanic GT3 day is and Robin (993 Varioram conversion) and I will come along for some fun []

John

Sundeep car pic is as follows:

Most of the Titanic fast-gang were in Germany tearing up the Autobahns and overtaking police cars at high speed with impunity. They visited Gemballa, Ruf and Manthey Racing before finishing up lapping the 'ring.

Would love to do Oulton-Park but the journey there is a durdge from Kent. Similar distance from home to Spa for us so generally Spa wins the vote. Oulton does sound fantastic and one day I'll get there.

 

[jmspear]

Gary, same issue for me (distance) as I am cheltenham based, I love Brands, but again a bit of distance, would love to do the ring (hope to get it organised this year) meantime I will have to "make do" with Brands, Goodwood and Castle Combe, very keen to see how the car performs at Combe and Goodwood which are circuits which seem to particularly favour GT3 (can't get near them - in the past).

Hope to meet some of the Titanic fast gang and have some safe fun. A Porsche fanatic is only bettered by a fast porsche fanatic who drives well and as their car was designed to be driven, whatever the model. Looking forward to meeting some of the gang through the year having some track fun and swapping tales and being shown the error of my ways[]

Maurice, I understand that his motor has different pistons, is 3.8 (as the base is the RS) a different induction system and i think motec, but don't quote me the only thing I know for definite is the pistons, also not at all sure how user friendly it is on the road, but awesome on the track!

I really do think the head conversion is the limit for us mere mortals, not least of which the cost for the next stage would be prohibitive!

The value of the conversion is as a sensible (and hopefully much safer for the engine) conversion for the track which is still perfect on the road - assuming you wish to stick with a 993 and not go down a 964RS, GT3 or 993RS route - last would be my preferred route but bloody dear at the moment and I wouldn't get the kick i have got out of modding my car which has been half the fun.

I was looking at supercharging - even went so far as to buy a kit (off ebay) but never fitted it as felt it would need charge cooler and extra oil cooling, plus more plumbing for mixture monitoring etc (for the track) - plus your advice on the differences between the std 993 and the 993 turbo and a track day at Donnington where three (non Porsche) modified turbo cars all blew up (as did the Skyline at Oulton on Saturday).

Finally the supercharger performance is mainly at the bottom end when what you really need is top end for the track which is where you spend most of your time.

The cost for a track friendly supercharger conversion equalled the head conversion, so it went back onto ebay and I went down the head route.

I have to say the conversion is serious fun []