The Porsche 924 Owners Club

Dedicated to the Porsche 924
The Porsche 924 Owners Club
It is currently Mon Nov 30, 2020 8:10 am

All times are UTC [ DST ]




Post new topic Reply to topic  [ 83 posts ]  Go to page Previous  1 ... 3, 4, 5, 6, 7, 8, 9  Next
Author Message
 Post subject: Re: So this turned up today
PostPosted: Sat Nov 11, 2017 6:26 pm 
Offline
Club Member
User avatar

Joined: Sat Jan 30, 2010 11:13 pm
Posts: 17403
Location: Somerset
Model: TheOnly Way Is Turbo
Looks like a #4 turbine housing v's #6 but I could be wrong. There are castings on both hot and cold side. Not conclusive what compressor wheel, but if it is an S2 #4 turbine then its quite possible the compressor is an S2 2660 wheel which is far better than an S1 2470 .

Issue is so many are not original, been replaced, rebuilt, swapped by OP, garages and turbo specialists its hard to be 100% certain unless you built it yourself.

See here - https://porsche924.co.uk/forum/viewtopi ... 47&t=13684

Given the results on the dyno, I wouldn't worry too much

_________________
Steve - Joined: Sat Jan 30, 2010 10:13 pm......think I have lost far too much time in this forum.........
1981 924 Carrera GT/S rep race car - Signal Yellow Too much to do, to little time and money!
1979 924 Turbo Series 1 - Alpine White & Guards Red 10yrs owned and counting
2021 Skoda Superb Sportline Plus iV Hybrid Estate awaiting delivery...
2017 VW Passat Variant GTE Advance soon to be retired....
2015 Nissan Leaf Tekna Continues to 'build trees'


Top
 Profile  
Reply with quote  
 Post subject: Re: So this turned up today
PostPosted: Sat Nov 11, 2017 8:01 pm 
Offline
Club Member
User avatar

Joined: Tue Aug 17, 2010 1:15 am
Posts: 1220
Location: Sheffield
Model: 924 Turbo S1
Carrera RSR wrote:
Looks like a #4 turbine housing v's #6 but I could be wrong.


As suspected - if so it explains the phat torque at 3000rpm with 1bar and the less-than-expected peak rpm power. Running a 'smaller' turbo at higher boost (within reason) gives phat torque. Ideal for the road.

_________________
"Success is a journey, not a destination"


Top
 Profile  
Reply with quote  
 Post subject: Re: So this turned up today
PostPosted: Sat Nov 11, 2017 8:08 pm 
Offline
Club Member
User avatar

Joined: Tue Dec 29, 2009 11:16 am
Posts: 4275
Location: Stoke On Trent
Model: Supercharged 924
All good (and interesting points) but I still find it odd, or should I say a huge coincidence, that every dyno curve for a 924 I've ever seen falls off at 5.2krpm - whether it's turbo or not. Surely there must be a common component responsible for that? Has anyone seen the plots for a variety of cam shafts - I've always had my money on it being the cam profile as the cause/explanation?

I'm not saying that it's a bad thing as such, but it certainly limits the BHP figure for bragging rights!

I would love to try a more aggressive cam on mine and see how the drivability/ engine character changes, but can't justify £300 without some confidence I will like it!!

_________________
924T engine with Eaton M90 Supercharger (DB7), 565cc injectors, coil pack ignition, Adaptronic ECU, Custom Air/water charge cooler, Wideband O2 + 4x EGT. 4pot Brembos, Spax adjustable dampers. 951 G'box with LSD & cooler, 944T style bumper. HID Lo-Pro headlights. 968 mirrors, handles + spoiler. Zender rear valance. Custom side skirts, Forged 17" wheels (8J front, 9J rear). Custom hubs (5x114.3 PCD), Twin circuit coolant re-route (2 pumps, 2 'stats, 2 radiators), 6 gauge centre console.


Top
 Profile  
Reply with quote  
 Post subject: Re: So this turned up today
PostPosted: Sat Nov 11, 2017 9:02 pm 
Offline
Club Member
User avatar

Joined: Sat Jan 30, 2010 11:13 pm
Posts: 17403
Location: Somerset
Model: TheOnly Way Is Turbo
Mittelmotor sent me a comparison table of cams. Unfortunately they did not send me the list of cams used in the comparison test!! Double unfortunately they did not test the Kent cam that is in my car nor suggest where it sits in the table so I could see if it’s good or not. I guess if my car was sat in their workshop and my credit card is poised for use I’d get more feedback. As it is Michael has been very open on most questions I posed to him. But some specifics were kept up his sleeve.

_________________
Steve - Joined: Sat Jan 30, 2010 10:13 pm......think I have lost far too much time in this forum.........
1981 924 Carrera GT/S rep race car - Signal Yellow Too much to do, to little time and money!
1979 924 Turbo Series 1 - Alpine White & Guards Red 10yrs owned and counting
2021 Skoda Superb Sportline Plus iV Hybrid Estate awaiting delivery...
2017 VW Passat Variant GTE Advance soon to be retired....
2015 Nissan Leaf Tekna Continues to 'build trees'


Top
 Profile  
Reply with quote  
 Post subject: Re: So this turned up today
PostPosted: Sat Nov 11, 2017 9:09 pm 
Offline
Club Member
User avatar

Joined: Tue Dec 29, 2009 11:16 am
Posts: 4275
Location: Stoke On Trent
Model: Supercharged 924
You can't blame them for that! Although it was definitely worth asking!!

What does your torque do after 5k?

:beer:

_________________
924T engine with Eaton M90 Supercharger (DB7), 565cc injectors, coil pack ignition, Adaptronic ECU, Custom Air/water charge cooler, Wideband O2 + 4x EGT. 4pot Brembos, Spax adjustable dampers. 951 G'box with LSD & cooler, 944T style bumper. HID Lo-Pro headlights. 968 mirrors, handles + spoiler. Zender rear valance. Custom side skirts, Forged 17" wheels (8J front, 9J rear). Custom hubs (5x114.3 PCD), Twin circuit coolant re-route (2 pumps, 2 'stats, 2 radiators), 6 gauge centre console.


Top
 Profile  
Reply with quote  
 Post subject: Re: So this turned up today
PostPosted: Sat Nov 11, 2017 9:23 pm 
Offline
Club Member
User avatar

Joined: Sat Jan 30, 2010 11:13 pm
Posts: 17403
Location: Somerset
Model: TheOnly Way Is Turbo
DrJohn wrote:
You can't blame them for that! Although it was definitely worth asking!!

What does your torque do after 5k?

:beer:


Posted the May dyno day sheets a few pages ago. Both mine and Richard K turbos torques drop off post 5k.

_________________
Steve - Joined: Sat Jan 30, 2010 10:13 pm......think I have lost far too much time in this forum.........
1981 924 Carrera GT/S rep race car - Signal Yellow Too much to do, to little time and money!
1979 924 Turbo Series 1 - Alpine White & Guards Red 10yrs owned and counting
2021 Skoda Superb Sportline Plus iV Hybrid Estate awaiting delivery...
2017 VW Passat Variant GTE Advance soon to be retired....
2015 Nissan Leaf Tekna Continues to 'build trees'


Top
 Profile  
Reply with quote  
 Post subject: Re: So this turned up today
PostPosted: Sat Nov 11, 2017 9:52 pm 
Offline
Club Member
User avatar

Joined: Tue Aug 17, 2010 1:15 am
Posts: 1220
Location: Sheffield
Model: 924 Turbo S1
DrJohn wrote:
Has anyone seen the plots for a variety of cam shafts - I've always had my money on it being the cam profile as the cause/explanation?
I would love to try a more aggressive cam on mine and see how the drivability/ engine character changes, but can't justify £300 without some confidence I will like it!!


I think you're right about the cam John. It's a breathing issue, cam+head whether it be the 24 head or Turbo head IMO.

Comparing this car to a real GT though, you'd expect very similar characteristics and more power running 1 bar versus the ~0.78 bar of a GT. The rolling road makes power figures suspect but the torque curve should be accurate which is why I think Steve's probably right about the #4 turbine housing - shoving more boost through it will give great midrange torque but the size still limits outright power. Not an issue for a road car IMO as most people change up before 5000rpm.

I think I have the curve for Joakim's engine somewhere - that had a very aggressive cam and a fully worked head.

_________________
"Success is a journey, not a destination"


Top
 Profile  
Reply with quote  
 Post subject: Re: So this turned up today
PostPosted: Sat Dec 02, 2017 10:16 pm 
Offline
Club Member

Joined: Tue Jul 29, 2014 1:28 pm
Posts: 1503
Location: emsworth hampshire
Model: 924 gt 924 n/a
It's defiantly got torque :drool:
I'm going to send the car to Jkm performance in Portsmouth in the new year for a bit of reprogramming on the map and have them set it up with two programs one for road use and one for fast road and track use.
They can also fix the cold start and hot start issues with the hot start being the most anoying one when your In a petrol station. :whistle: and this car has no kjet which I can almost probably fix on the drive. :dope:
In the meantime the rad has a leak so that needs replacing and the bottom hose needs replacing, it's then going into aw motor sport next week for a look at the rear brakes they are binding so there going to be 're sealed and serviced I could do it myself but it's quicker to sort on a two post lift :smile:

_________________
https://porsche924.co.uk/forum/viewtopi ... 24&t=14424
https://porsche924.co.uk/forum/viewtopi ... 24&t=21262
https://porsche924.co.uk/forum/viewtopi ... 24&t=22223


Top
 Profile  
Reply with quote  
 Post subject: Re: So this turned up today
PostPosted: Sat Dec 09, 2017 5:47 pm 
Offline
Club Member

Joined: Tue Jul 29, 2014 1:28 pm
Posts: 1503
Location: emsworth hampshire
Model: 924 gt 924 n/a
a couple of hours on the ramps at aw motorsport on thursday to find out why the new rear brakes are binding and they found the hub is slightly oval and causing the hadbrake shoes to bind :bang: they have now been backed off a little and are better but i think ill find a new set at some point

_________________
https://porsche924.co.uk/forum/viewtopi ... 24&t=14424
https://porsche924.co.uk/forum/viewtopi ... 24&t=21262
https://porsche924.co.uk/forum/viewtopi ... 24&t=22223


Top
 Profile  
Reply with quote  
 Post subject: Re: So this turned up today
PostPosted: Sat Dec 30, 2017 7:09 pm 
Offline

Joined: Wed Jun 29, 2016 7:42 am
Posts: 105
Model: 924
Just seen this John. Stunning machine. Cant wait to see it! Well done!


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 83 posts ]  Go to page Previous  1 ... 3, 4, 5, 6, 7, 8, 9  Next

All times are UTC [ DST ]


Who is online

Users browsing this forum: No registered users and 17 guests


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 post attachments in this forum

Search for:
Jump to:  
© 2009-2020 The Porsche 924 Owners Club - Powered by phpBB