update on projects

Do you have a Puma that is a project? Do you want to track the progress with your own thread? Feel free to do it here.

Moderator: Moderators

User avatar
madhillbilly17
Project Petrol Head!
Project Petrol Head!
Posts: 852
Joined: Sun Jan 04, 2009 5:41 pm
Model: Other
Location: Hampshire

Re: update on projects

Post by madhillbilly17 » Sat Apr 28, 2012 11:58 am

hi mac, its a plate that goes in between the block and head with 2 head gasket either side, it lowers the compression so you can run more boost safely.
0 x

User avatar
Flying Scotsman
Project Elder
Project Elder
Posts: 6435
Joined: Wed Aug 18, 2010 10:56 pm
Model: Turbo
Location: New York, New York
Contact:

Re: update on projects

Post by Flying Scotsman » Sat Apr 28, 2012 12:02 pm

madhillbilly17 wrote:hi mac, its a plate that goes in between the block and head with 2 head gasket either side, it lowers the compression so you can run more boost safely.
Ah i get it... like a flange almost.... where would i get one of these or would i have to get one fabricated?
0 x
Image

User avatar
PumaNoob
Guru!
Guru!
Posts: 2709
Joined: Mon Jul 20, 2009 5:28 pm
Model: FRP
Location: Under my car

Re: update on projects

Post by PumaNoob » Sat Apr 28, 2012 1:51 pm

The decompression plate increases the size of the combustion chamber. The more air and fuel you can get into a combustion chamber, the bigger the bang (as long as that mixture isnt to hot). The lower the compression ratio, the less the gas in the combustion chamber is compressed so less heat is produced, so safer running all around. You can email craig@lasermaster.com for one, i think they are about £50. Its the same sort of idea as low compression pistons, but the pistons increase the volume of the combustion chamber by having a dish in them, or having the head of the piston skimmed.

The downside to lower compression is that there will be slightly more lag, and pound for pound of boost, there will be slightly less power.If theres 200bhp on a 10.5:1 engine at 10 psi, on an 8.5:1 engine, there will be about 190bhp. But then you can safely run about 18 psi of boost in an 8.5:1 engine, up to about 22psi with high octane fuel and an air fuel ratio of about 11:1 and the right ignition mods. With a decent turbo that would see the 1.7 past 300bhp with the right mods and strengthening. At 10.5:1, i really wouldnt push the boost past about 10psi, and thats only with the right mapping and fuelling. Lower compression gives you more scope for error and fluctuation in temperature and fuel quality and ecu lag (it takes the ecu time to process information and send the cerrect signals to the injectors and the sparkplugs)
0 x
Image

FRP 2.3 Duratec Turbo Is BACK!!!!

User avatar
Flying Scotsman
Project Elder
Project Elder
Posts: 6435
Joined: Wed Aug 18, 2010 10:56 pm
Model: Turbo
Location: New York, New York
Contact:

Re: update on projects

Post by Flying Scotsman » Sat Apr 28, 2012 1:59 pm

You mentioned the right mods and strengthening and ignition mods.... could you elaborate please?
0 x
Image

User avatar
PumaNoob
Guru!
Guru!
Posts: 2709
Joined: Mon Jul 20, 2009 5:28 pm
Model: FRP
Location: Under my car

Re: update on projects

Post by PumaNoob » Sat Apr 28, 2012 2:12 pm

Well a standard engine wouldnt be able to take 300bhp, and im not sure the head would flow enough for 300bhp either. The dynamic compression ratio increase from the turbo would increase power to a certain extent, but you can only increase that so much without it going bang. If i was going for massive power with the 1.7, id look at a good set of main bearings, a good set of big end bearings, stronger con rods, stronger pistons with a thicker crown to help disperse the heat, id go for alchol injection to cool the charge down, the head would have to be flowed properly and bigger valves and valve seats fitted, and of course the right turbo would need to be used, for peak figures id go for a GT2071R or even a GT30, loads more lag, but top figures produced. For drivability and lower down power id go for GT28R or possibly GT28RS (thats what i have on my 2.0). The smaller turbos are slightly harder to get bigger top end power from, without going past its peak efficiency.

Turbo size is a very important factor, and the use of the car would be the main decider. A 1.7 with a GT30 on would be virtually un-usable on the street, you could drive it but the power would be so unpredictable because youd have about 100bhp, then at about 5500rpm-6000rpm, youd get another 200 horses thrown into the mix! But it would be good on a drag strip, once your in boost, nothing will catch you!!

P.s if you want to continue with this topic, it might be better to talk on the turbo talk thread rather the cluttering up Pauls project thread, unless Paul is ok with it??
0 x
Image

FRP 2.3 Duratec Turbo Is BACK!!!!

paulob1
Project Petrol Head!
Project Petrol Head!
Posts: 918
Joined: Fri Jul 22, 2011 5:55 pm
Model: 1.7

Re: update on projects

Post by paulob1 » Sun Apr 29, 2012 7:53 pm

I am cool, it all adds to my knowledge, you have so much info that I am happy to hear...I think I am going for the t25 for my 300 bhp engine...I will do a bit of head work but think with the std valves and frp cams I should be okay...going to try with the std head first then maybe remove the VVT at a later date.
0 x
n/a 220 bhp screamer frp broken now with chris for repairs
turbo frp, going to make 370.3 bhp awaiting cv joint and MOT
turbo puma getting new engine. on the way...
turbo FRP awaiting engine build and roll cage fitting.
FRP 4 awaiting full rebuild

User avatar
PumaNoob
Guru!
Guru!
Posts: 2709
Joined: Mon Jul 20, 2009 5:28 pm
Model: FRP
Location: Under my car

Re: update on projects

Post by PumaNoob » Wed May 02, 2012 2:58 am

I think you might struggle with a journal bearing T25 turbo to get more then about 220-230bhp. They are generally out of their efficiency range past about 200bhp. But again, if you try it, you can get set up, see what it makes, and swap it out for a T28 or GT28, as the flange is the same, so if you get a 5 bolt dowwnpipe flange on it, you will be able to just swap it out. After their efficiency range, they start to blow hot air, so you can end up loosing a bit of power, and restricting flow. Mine is a T25 on my green puma, and a large T25, and the diffrerence between 12 psi and 14psi of boost is nothing, i got my best 1/4 mile time at only 10psi.
0 x
Image

FRP 2.3 Duratec Turbo Is BACK!!!!

paulob1
Project Petrol Head!
Project Petrol Head!
Posts: 918
Joined: Fri Jul 22, 2011 5:55 pm
Model: 1.7

Re: update on projects

Post by paulob1 » Fri May 04, 2012 10:02 pm

you see thats what I thought then lightning motorsport say it is the turbo they use for up to 300 bhp engine...am confused...going to go for the gt28 then and stop messing about...I want a reliable motor too not an over stressed engine...
0 x
n/a 220 bhp screamer frp broken now with chris for repairs
turbo frp, going to make 370.3 bhp awaiting cv joint and MOT
turbo puma getting new engine. on the way...
turbo FRP awaiting engine build and roll cage fitting.
FRP 4 awaiting full rebuild

User avatar
PumaNoob
Guru!
Guru!
Posts: 2709
Joined: Mon Jul 20, 2009 5:28 pm
Model: FRP
Location: Under my car

Re: update on projects

Post by PumaNoob » Fri May 04, 2012 10:19 pm

Well they should know more about it then me, i doubt they would say it without having evidence to back it up. I just know a lot of cars that come with a T25 turbo as standard seem to max out just over 200bhp. The rover T16 engine came with a T25 and i think they struggle to get much over 220 with the standard turbo. Even the very efficient nissan 200sx doesnt get much more then 200 from the standard turbo. Maybe its a roller bearing T25, that should carry more power through to redline. Or maybe its a modified or larger T25. If a smaller turbo will work to the power you want, it would be better to use it, because youll get less lag. I dont know anyone or havent heard of anyone thats got more then about 240 with a T25, but then im a carpenter not a mechanic :lol: All my advice is from personal experience, but i havent tried everything!
0 x
Image

FRP 2.3 Duratec Turbo Is BACK!!!!

demonskull13
Project Regular
Project Regular
Posts: 427
Joined: Sat Jun 14, 2014 8:02 pm
Model: 1.7
Location: worcester

update on projects

Post by demonskull13 » Sun Sep 10, 2017 3:55 pm

paulob1 wrote: saab T25
hi i am following your thread as im doing pretty much the same myself

Jason

:P :thumbs: :ok:
0 x

Post Reply

Return to “ProjectPuma”