Welcome to 911UK
The only place for Porsche, 911uk is the definitive enthusiast and resource site for the Porsche 911.
Registration is fast, simple and absolutely free, so join up today for full access to the site and benefit from latest member offers.

Porsche Classifieds
Sell Your Porsche on 911uk
Create a Free Classified Advert
Search Ads
Classified Adverts FAQ
Trade Classified Information
Buyer & Seller Fraud Protection
Consumer Rights Act
Pre Purchase Inspection (PPI)
Porsche Car Sourcing
Porsche Cars Wanted
Official Porsche Centre Reviews
Model
Stock
Porsche 911
991 : 2011- 15
992 : 2019- 0
997 : 2004- 66
996 : 1997-2005 30
993 : 1993-1998 5
964 : 1989-1993 2
Carrera 3.2 : 1983-1989 2
Carrera SC : 1977-1983 1
930 Turbo : 1975-1989 0
Early 911 : 1964-1977 0
Porsche Other Models
Classic : 1950-1965 0
Boxster : 1997- 20
Cayman : 2005- 13
Cayenne : 2003- 2
Macan : 2014- 2
Panamera : 2009- 1
912-914-924-928-944-968 1
959 - CarreraGT - RaceCar 0
Car Parts For Sale & Wanted
Other Items For Sale & Wanted
Wheels Tyres For Sale & Wanted
Number Plates For Sale Wanted

Porsche Services
Porsche Body Shop Repair
Paint Protection & Wrapping
Porsche Classic Insurance
Porsche Classic Parts
Porsche Classic Restoration
Porsche Design Collection
Porsche Engine Gearbox Rebuild
Porsche Heritage & History
Porsche News
Porsche Picture Gallery
Win a New Porsche 911

Porsche Parts
Body Parts, Body Styling
Brakes, Clearance
Electrical, Exhausts
Engine Cooling, Engine Electrical
Engine Rebuild, Heating Cooling
Interior Incar, Lighting
Rubber Seals, Service Parts
Steering, Suspension
Transmission, Workshop Tools
Early 911, 911 - 930, 928 - 968
964 - 993, 996 - 997, Boxster
Cayman, Cayenne, Panamera

Porsche Model Range
911 [992] 2018-Current
Porsche 911 [992]
911 [991] 2011-2019
Porsche 911 [991]
911 [997] 2004-2012
Porsche 911 [997]
911 [GT] GT1-GT2-GT3
Porsche 911 [GT]
911 [996] 1997-2005
Porsche 911 [996]
911 [993] 1993-1998
Porsche 911 [993]
911 [RS] RS-RSR
Porsche 911 [RS]
911 [964] 1989-1993
Porsche 911 [964]
911 3.2 1983-1989
Porsche 911 3.2 Carrera
911 SC 1977-1983
Porsche 911 SC
911 [Early] 1964-1977
Porsche 911 [Early]
Boxster & Cayman
Porsche Boxster & Cayman
Cayenne & Panamera
Porsche Cayenne & Panamera

911uk Site Partners

Post new topic   Reply to topic
Author Message
crash7
Hockenheim


Joined: 28 May 2011
Posts: 638



PostPosted: Wed Jul 17, 2019 9:20 pm    Post subject: Reply with quote

Dammit: - It makes cira 285 ft/lbs at 4600, its at 250ft/lbs by 2500, and doesn’t drop below this until 6750.


Demon: - Going by your signature we are indeed treading similar pathes. – When I actually think about the resonator, it makes sense, removing it does not increase airflow to the engine, but it does increase the noise, how does it do this, by upsetting the airflow. – You could also question why Porsche would add the resonator if it doesn’t contribute anything.


Jcharalambides: - What is the spec on your engine build? 3.9?


Infra : - The 3.6 comes with less problematic heads out of the boxes and is probably a better place to start than the 3.4, however, and this is personal, I prefer the look of the 996.1 aero which I was set on when I started, being honest I didn’t initially plan on the engine work!


Y2K : – Cheers for the dyno link, this further confirms to me that 275ish, are where the 3.4’s are, interestingly the torque seems low, circa 225 ft/lb - Would be interesting to see what the 3.6 M96 is making.

I was surprised at the weight on mine, and was hoping to be closer to 1250kgs particularly based on the numbers that are banded around the internet, unfortunately not.

I know I can lose more, the standard wheels are heavy, I could save 20kg’s there as an easy win, I have previously had a set of Oz alleggerita, actually had two, but I wanted to stick with the standard look so moved them both on.

I do however have a set of 996 Cup Magnesium E88’s that I will eventually get around to fitting, the saving will be less than the Oz’s, circa 15kg, but I can live with that as I think the wheels rock , out and out weight saving is not the ultimate goal.

Tyres are also a place to save that is often over looked, with most concentrating on the wheels. When the car was weighted it was running Yoko AD08R, which are a great tyre, but heavy, a 225 is heavier than a 245 Cup 2, the E88’s will run with Cup2’s, which are also a quicker tyre.

Lightweight battery, Odessey etc is an easy, cheap, big win on weight, however can be problematic if you dont keep it constantly on a ctech. - Li could be the perfect solution but I have no experience.

The JRZ’s are superb, however, they are an out and out motorsport damper and as such are designed to run with high spring rates on race cars. - As the spring rates are high you also need to run lots of compression and rebound to ensure the damper is damping and your not just sat on the spring, I made this mistake at Thruxton when I had initially fitted them and it led to losing the rear coming out of Village!

All of this means a stiff ride, perfectly compliant on smooth surfaces, but rutted B roads, not so much!

Being transparent the whole suspension setup and geometry does not really lend itself particularly well to large swaths of British roads!

Spring rates for context.,

996 GT3 runs R: 370 F:200 - Revised on the 996.2 GT3 to R: 542lbs F:228

Cup Car: R:1484 F:1370

I run, R:950 F:800 (Main springs, both with 150 tenders)

My fronts are probably a little too stiff, noticeable on track when braking hard on bumpy surfaces, brings in the ABS when the tyres still have traction, most annoying, I can counter via the rebound damping, to an extent, however I think a little softer would dial out a little more understeer and help with the braking.

Your welcome to try it, do you track your car? trackday meet?

Last edited by crash7 on Thu Jul 18, 2019 8:58 am; edited 2 times in total
 
  
View user's profile Send private message
   
crash7
Hockenheim


Joined: 28 May 2011
Posts: 638



PostPosted: Wed Jul 17, 2019 9:26 pm    Post subject: Reply with quote

Pictures, may be of interest to some.,

Engine case being machined for the additional crank shaft bearing. – The crank has a long overhang the additional bearing provides the crank extra support.

To further aid the crank as oppose to the dual mass flywheel, circa 13kg’s, being hung off it, a Lightweight flywheel was fitted, circa 6Kg’s.

This should make for longevity and reliability. – This is the first engine, outside of a few race cars, that Hartech have fitted this to.

That said when the crank was removed the original bearings etc were in good shape and that was without the extra bearing and a dual mass flywheel, the car had covered 90k miles and several trackdays
 



Crank bearing 2.jpg
 Description:
 Filesize:  28.24 KB
 Viewed:  976 Time(s)

Crank bearing 2.jpg



Hartech crank bearing.jpg
 Description:
 Filesize:  37.41 KB
 Viewed:  976 Time(s)

Hartech crank bearing.jpg


  
View user's profile Send private message
   
crash7
Hockenheim


Joined: 28 May 2011
Posts: 638



PostPosted: Wed Jul 17, 2019 9:28 pm    Post subject: Reply with quote

Block
 



Hartech Block1.jpg
 Description:
 Filesize:  45.31 KB
 Viewed:  970 Time(s)

Hartech Block1.jpg


  
View user's profile Send private message
   
Y2K
Montreal


Joined: 08 Mar 2016
Posts: 505
Location: Hampshire


PostPosted: Thu Jul 18, 2019 12:10 am    Post subject: Reply with quote

Thanks for the info RE suspensions. I’m a complete novice really so had mine set up by 9E. I had a play with bump and rebound and quite happy with it now, but second opinion always welcome so track meet sounds good.

I got Abingdon this Friday actually, then Oulton in September and Blyton Park in October. IIRC you’re based at Surrey/Sussex? PM me if/when you’re going to Thruxton / Castle Combe / Donington etc, I’ll join you if my schedule allows.
_________________
2005 996 GT3 mk2
1999 Integra DC2
 
  
View user's profile Send private message
   
Jamesx19
Nürburgring


Joined: 10 Jul 2015
Posts: 455
Location: Brighton


PostPosted: Fri Jul 19, 2019 6:39 am    Post subject: Reply with quote

Really interesting read, thanks Crash.

Honest data and feedback is very hard to come b on the internet, so all the more valuable when it's shared.

Nice one. Time to enjoy it now!
_________________
1998 C2 Manual + The Full Hartech.
 
  
View user's profile Send private message
   
sp1ke
Trainee


Joined: 07 May 2009
Posts: 64



PostPosted: Sun Jul 21, 2019 1:37 pm    Post subject: Reply with quote

Fascinating thread, thanks for sharing.

I note you mentioned you'd found the 997s 3.8 plenum to be the optimum choice.
I'm curious to hear if you tried the 3.6 stock plenum & what the gains where with the 3.8 plenum, as this would be a relatively cheap mod for the rest of us.
Also would you happen to know the difference in dimensions between the 3.6 & 3.8 plenums? & can you share the part number you used?

For completeness I'll add the graph from the original Porsche hardback catalogue for the stock 3.6 as a comparison to the one Dammit shared for the stock 3.4.
_________________
----------
996.2 C2
 



996_36_graph.jpg
 Description:
 Filesize:  1.85 MB
 Viewed:  749 Time(s)

996_36_graph.jpg


  
View user's profile Send private message
   
NedHan79
Nürburgring


Joined: 08 Nov 2018
Posts: 487



PostPosted: Sun Jul 21, 2019 4:24 pm    Post subject: Reply with quote

I had all the details written out and for some reason I lost the screen. Typical
98 c2 3.4
Hh removal with piper x foam filter
Denso iridium plugs
Surefire coil packs
Unknown ss exhausts, manifolds and cats
97 Ron as in Northern Ireland.
_________________
#modified996mk1
 



FECC3EFF-C36A-4279-89E9-0FD704067FE5.png
 Description:
 Filesize:  1.12 MB
 Viewed:  715 Time(s)

FECC3EFF-C36A-4279-89E9-0FD704067FE5.png


  
View user's profile Send private message
   
jcharalambides
Newbie


Joined: 14 Jan 2019
Posts: 32



PostPosted: Mon Jul 22, 2019 1:43 pm    Post subject: Reply with quote

@crash7 - my rebuild did not entail a displacement increase. Mods include different cams, ported and flowed heads and valve seats, new liners, pistons etc.

I am still waiting for the Dyno sheet for which the tuner is taking his sweet time to send over to RPM Technik... It will be interesting to see the numbers on this. Ultimately if they are good, you could combine these mods with an upgrade to 3.9 or something.

It's great that you got to try things on-and-off while on the dyno. For some reason there is very little actual science backing a lot of the tuning mods!
 
  
View user's profile Send private message
   
Dammit
Watkins Glen


Joined: 23 Sep 2016
Posts: 2229



PostPosted: Mon Jul 22, 2019 2:08 pm    Post subject: Reply with quote

Schrick cams?
_________________
My 996, AKA Project Ridiculous
 
  
View user's profile Send private message
   
Jamie Summers
Österreich


Joined: 29 Oct 2002
Posts: 901
Location: Esher, Surrey

1992 Porsche 964 RS

PostPosted: Fri Jul 26, 2019 2:10 pm    Post subject: Reply with quote

I appreciate it's not quite comparing apples with apples, but I have the original Cayman "RS" development car that Autofarm produced about 10 years ago.

It started life as a regular 987.1 S ie the M97 3.4L lump. Autofarm subjected this to one of their 3.7L Silsleeve engine conversions. In addition to many of the same bits and pieces that Hartech do as standard, Autofarm also fitted the Shrick cams, IPD plenum GT3 throttle body and a custom carbonfibre airbox. It also has stainless decat headers and Miltek back section (also decat).

The engine was dyno-mapped by the now departed Bob Watson and showed 367bhp, backed up by a dyno print from a different dyno a couple of years later showing a very similar number.

The power delivery is very linear with strong low-down torque. Getting the thing to cool properly has been the major challenge, but I think that is as much to do with the mid-engined lay out as the engine itself. I have now also gone down the line of fitting TTP Oilsafer pumps on both banks of heads together with an additional external oilcooler, deep baffled sump and larger 997 water/oil heat exchanger, low temp therm, lightweight clutch and flywheel and under drive pulley.

I think there is still more on the table with a bit more dyno time. Parr had it on their dyno relatively recently and commented that the map was fairly basic and could be improved.

Clearly comparisons with a Hartech M96 3.7 are not entirely fair, but what is interesting is that even with many of the bolt-on "performance" mods eg plenum, throttle body and airbox, which the OP found to be power-reducing, there is still a material improvement in power output over the Hartech M96, which presumably must come largely down to the cams and exhaust ???
_________________
'06 Autofarm Cayman RS Development Car
‘99 996 C2
Ex '92 964 RS
Ex '93 968 CS
Ex '90 Clio Mk1 Cup Racer
Ex '90 964 C2
Ex '89 Carrera 3.2
 
  
View user's profile Send private message Send e-mail
   
Dammit
Watkins Glen


Joined: 23 Sep 2016
Posts: 2229



PostPosted: Fri Jul 26, 2019 2:41 pm    Post subject: Reply with quote

Interesting- thanks for posting the details.

M97 has 3.2mm larger diameter valves than the M96, not sure which Schrick cams were fitted but they’ll certainly have more lift than the M96 3.2/3.4.

Be very interesting to see what yours makes with a stock 997 intake- although you’d need to do some work to get it in there. From chatting with Wayne it it might produce a surprising amount more.
_________________
My 996, AKA Project Ridiculous
 
  
View user's profile Send private message
   
Jamie Summers
Österreich


Joined: 29 Oct 2002
Posts: 901
Location: Esher, Surrey

1992 Porsche 964 RS

PostPosted: Fri Jul 26, 2019 3:32 pm    Post subject: Reply with quote

Yes, going by the OP's experience a stock intake may yield more. Is there much difference between the 987 and 997 intakes ? The Autofarm work had been done on the engine long before I bought it, so I have no real idea what the stock 987 set up looks like.
Interaction between the intake and exhaust sides of the engine is also interesting and untested in this scenario. I wonder if the modified intake side's capacity to flow more air is optimised by a freer flowing exhaust system (like my fully decatted system) ? ie mods on both sides producing a positive result versus the negative experience of just modding the intake side.
I realise I may be clutching at straws !!!
I have long been meaning to visit Wayne, but it's a heck of a long way from me so don't want it to be a wasted trip.
Out of curiosity I've also fitted an IPD plenum, K&N intake kit, under-drive pulley, Top Gear headers and 200 Cell back section to my early 3.4 996. I have no before or after dyno figures to offer, and the car is certainly nowhere near as quick as the Cayman, but it makes a pleasing noise and seems to go very nicely. It does not feel slower than pre modification, but that might just be my wallet deceiving my brain !!!
_________________
'06 Autofarm Cayman RS Development Car
‘99 996 C2
Ex '92 964 RS
Ex '93 968 CS
Ex '90 Clio Mk1 Cup Racer
Ex '90 964 C2
Ex '89 Carrera 3.2
 
  
View user's profile Send private message Send e-mail
   
Dammit
Watkins Glen


Joined: 23 Sep 2016
Posts: 2229



PostPosted: Fri Jul 26, 2019 4:50 pm    Post subject: Reply with quote

I have a 997 intake which you are welcome too if you can collect it.

I’m in Forest Hill, South East London.
_________________
My 996, AKA Project Ridiculous
 
  
View user's profile Send private message
   
crash7
Hockenheim


Joined: 28 May 2011
Posts: 638



PostPosted: Fri Jul 26, 2019 9:37 pm    Post subject: Reply with quote

Y2K – I would also class myself as a novice, you pick things up as you go, and as with most its trial and error!

I will drop you a PM, currently still running mine in, Castle Coombe, Brands, Silverstone & Bedford are where I end up most,


Sp1Ke - I believe the 3.4/3.6/3.8 plenums are all the same size, however the design of the 3.8 is better in that it the corners are smooth bends as oppose to a ‘T’ shape which improves flow.



The issue with getting HP out of a 3.4 are the heads this is largely because the 996 3.4 evolved from a basic original design of a 2.5 engine.

When Porsche wanted to make a 3.6 and 3.8 they realised they needed to increase the valve sizes and inlet areas to flow enough air at peak revs. They also knew that this would reduce mid-range torque so they made a new head and valve lift and timing system to get it back.

Porsche found this variable valve timing and lift system so effective they found they could use it on a 3.4 engine and still get a good torque curve out of it and hence the Cayman S evolved.

The 3.4 Cayman has variable valve lift and double the variable inlet valve timing (as the lower lift cam is timed differently and both cam lobes have variable timing adjustment). It also has bigger valve diameters and higher gas flow characteristics so can flow more air than a 996 3.4 head at high revs when the amount of time the valves are opened is shorter.

So in essence the 996 3.4 was stretched bigger to its limits while the 3.4 Cayman was reduced down from a head that already had higher flow characteristics.
 
  
View user's profile Send private message
   
Dammit
Watkins Glen


Joined: 23 Sep 2016
Posts: 2229



PostPosted: Fri Jul 26, 2019 9:50 pm    Post subject: Reply with quote

Pinched the table below from here: https://newsite.hamheads.com/2016/12/01/m96-m97-porsche-cylinder-head-specifications-and-general-info/
_________________
My 996, AKA Project Ridiculous
 



Screenshot 2019-07-26 at 22.49.43.png
 Description:
 Filesize:  161.67 KB
 Viewed:  357 Time(s)

Screenshot 2019-07-26 at 22.49.43.png


  
View user's profile Send private message
   
Display posts from previous:   
Post new topic   Reply to topic   All times are GMT - 12 Hours
Goto page Previous  1, 2
Page 2 of 2

 
Jump to:  

You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You can attach files in this forum
You can download files in this forum
You cannot post calendar events in this forum