tuning advice

lewist123 · 20-05-2008, 20:46

tenman - that was my origional plan (i have a turbo and a spare 135 engine) but i am realiably informed that the stock gearbox WILL be the limiting factor!

if i change the box then i may as well change the engine as welL!

My friend (Jimspeed) states that his old 120 bhp rally estelle used to eat gear boxes at 300 - 400 miles! I don't want to get into that!

KenONeill · 21-05-2008, 08:54

Is that the 4 speed ot the 5 speed unit? My tuning stuff from back in the day suggests that the 5 speed will survive a group B spec (twin 40s, 8 port head, bananas, 7_000rpm limit beyond which you start bending pushrods).

lewist123 · 21-05-2008, 09:00

5 speed unit!

what sort of power will a that make?

KenONeill · 21-05-2008, 09:04

None at all; gearboxes don't generate power!

Tenman · 21-05-2008, 09:18

heh... OK slight topic change... how do you go about getting other types of gearbox in a skoda, I imagine finding a gearbox upgrade that'll go in is far more difficult than an engine... Alfasud box? these have the shafts coming out of the side of the box the same way that Skoda's do even if they are in the wrong end of the car as standard... (I've got 2 spare one's in my garage

...)

lewist123 · 21-05-2008, 11:43

i am looking at an audi box with the diff removed and installed 'the other way round'.

and ken...

i ment the engine mods!

lewist123 · 21-05-2008, 11:45

O, and i have been reliably informed, that the crank is the first thing to go at 7500 + rpm!

KenONeill · 21-05-2008, 12:29

The group B spec engine makes about 120bhp at 7_000rpm, and that rev limit comes from all of John Haugland and the Skoda GB and Works teams from back in the day. How much more authoritative a set of sources do you want?

hawkeracing · 21-05-2008, 16:37

Total hijack of my thread!! Ive bought a 136 Rapid now, so I am definitely going ahead.
At the moment I'm looking at a ported Felicia MPI head, electronic ignition, engine balance, cam (anyone any suggestions for a suitable profile?) and either bike carbs or a weber DCOE set up. Does anyone have any experience of the Weber DCOE options? I have seen someone talk about a single carb version for the 8 port head as well as the usual twin.
I absolutely must get over 100bhp as the rest of the class are running Pug 106 Rallyes.....and I'd like to be close if not in front.
Anyone any ideas on a rollcage for it...no one seems to make anything?

KenONeill · 21-05-2008, 16:53

There's somebody here has a Rapid with a single 40 on a reverse manifold IIRC.

Quick check of the stuff from back in the day says that Aleybars did cages for Estelles, which should fit a Rapid ok. The problem being that I don't have any even possibly valid contact details for them beyond the exchange being 0359 (now 01359?).

Kent Cams also developed a GpA cam, 296 duration, 9.35mm lift, timing 40/70, and it was available on exchange! You might get works or works replica pistons from Omega, and apparently Rover SD1 Vitesse valve springs are the right size and poundage.

**TaviaRS** · 21-05-2008, 17:04

Quote:

Originally Posted by KenONeill

There's somebody here has a Rapid with a single 40 on a reverse manifold IIRC.

Quick check of the stuff from back in the day says that Aleybars did cages for Estelles, which should fit a Rapid ok. The problem being that I don't have any even possibly valid contact details for them beyond the exchange being 0359 (now 01359?).

Kent Cams also developed a GpA cam, 296 duration, 9.35mm lift, timing 40/70, and it was available on exchange! You might get works or works replica pistons from Omega, and apparently Rover SD1 Vitesse valve springs are the right size and poundage.

Safety Devices took over Alleybars and don't make cages for them.

Have a chat with Erik at AAT (used to post on here as he can get cages for the folloowing:
Skoda 105, 120, 130, Favourit, Octavia

Telephone: +44 (0)1543 683051 or 306681

No joy on those, I have his mobile number somewhere. Say hi from me if you talk to him

hawkeracing · 21-05-2008, 17:38

Thanks for the replies....I dont absolutely have to have a cage as I will be running in road cars, but I would like one.
I take it standard valve springs arent up to the job??

KenONeill · 22-05-2008, 09:44

With the Kent cam, and running 7_000 to 7_500 rpm, depending on whether or not the pushrods bend before the crank breaks, I'd think not. You've increased the valve lift and peak revs, so significantly increased the valve speeds and accelerations, which means you need heavier springs to control them.

20-05-2008, 20:46	#21
lewist123 Briskodian Join Date: Jul 2007 Posts: 120 Thanks: 1 Thanked 4 Times in 4 Posts	Re: tuning advice tenman - that was my origional plan (i have a turbo and a spare 135 engine) but i am realiably informed that the stock gearbox WILL be the limiting factor! if i change the box then i may as well change the engine as welL! My friend (Jimspeed) states that his old 120 bhp rally estelle used to eat gear boxes at 300 - 400 miles! I don't want to get into that!

21-05-2008, 08:54	#22
KenONeill Briskodian Join Date: May 2006 Location: Normally somewhere in Scotland! Posts: 10,274 Thanks: 55 Thanked 481 Times in 473 Posts	Re: tuning advice Is that the 4 speed ot the 5 speed unit? My tuning stuff from back in the day suggests that the 5 speed will survive a group B spec (twin 40s, 8 port head, bananas, 7_000rpm limit beyond which you start bending pushrods).

21-05-2008, 09:00	#23
lewist123 Briskodian Join Date: Jul 2007 Posts: 120 Thanks: 1 Thanked 4 Times in 4 Posts	Re: tuning advice 5 speed unit! what sort of power will a that make?

21-05-2008, 09:04	#24
KenONeill Briskodian Join Date: May 2006 Location: Normally somewhere in Scotland! Posts: 10,274 Thanks: 55 Thanked 481 Times in 473 Posts	Re: tuning advice None at all; gearboxes don't generate power!

21-05-2008, 09:18	#25
Tenman Briskodian Join Date: Apr 2008 Location: Manchester Posts: 70 Thanks: 1 Thanked 0 Times in 0 Posts	Re: tuning advice heh... OK slight topic change... how do you go about getting other types of gearbox in a skoda, I imagine finding a gearbox upgrade that'll go in is far more difficult than an engine... Alfasud box? these have the shafts coming out of the side of the box the same way that Skoda's do even if they are in the wrong end of the car as standard... (I've got 2 spare one's in my garage ...)

21-05-2008, 11:43	#26
lewist123 Briskodian Join Date: Jul 2007 Posts: 120 Thanks: 1 Thanked 4 Times in 4 Posts	Re: tuning advice i am looking at an audi box with the diff removed and installed 'the other way round'. and ken... i ment the engine mods!

21-05-2008, 11:45	#27
lewist123 Briskodian Join Date: Jul 2007 Posts: 120 Thanks: 1 Thanked 4 Times in 4 Posts	Re: tuning advice O, and i have been reliably informed, that the crank is the first thing to go at 7500 + rpm!

21-05-2008, 12:29	#28
KenONeill Briskodian Join Date: May 2006 Location: Normally somewhere in Scotland! Posts: 10,274 Thanks: 55 Thanked 481 Times in 473 Posts	Re: tuning advice The group B spec engine makes about 120bhp at 7_000rpm, and that rev limit comes from all of John Haugland and the Skoda GB and Works teams from back in the day. How much more authoritative a set of sources do you want?

21-05-2008, 16:37	#29
hawkeracing Briskodian Join Date: May 2008 Posts: 44 Thanks: 0 Thanked 2 Times in 2 Posts	Re: tuning advice Total hijack of my thread!! Ive bought a 136 Rapid now, so I am definitely going ahead. At the moment I'm looking at a ported Felicia MPI head, electronic ignition, engine balance, cam (anyone any suggestions for a suitable profile?) and either bike carbs or a weber DCOE set up. Does anyone have any experience of the Weber DCOE options? I have seen someone talk about a single carb version for the 8 port head as well as the usual twin. I absolutely must get over 100bhp as the rest of the class are running Pug 106 Rallyes.....and I'd like to be close if not in front. Anyone any ideas on a rollcage for it...no one seems to make anything?

21-05-2008, 16:53	#30
KenONeill Briskodian Join Date: May 2006 Location: Normally somewhere in Scotland! Posts: 10,274 Thanks: 55 Thanked 481 Times in 473 Posts	Re: tuning advice There's somebody here has a Rapid with a single 40 on a reverse manifold IIRC. Quick check of the stuff from back in the day says that Aleybars did cages for Estelles, which should fit a Rapid ok. The problem being that I don't have any even possibly valid contact details for them beyond the exchange being 0359 (now 01359?). Kent Cams also developed a GpA cam, 296 duration, 9.35mm lift, timing 40/70, and it was available on exchange! You might get works or works replica pistons from Omega, and apparently Rover SD1 Vitesse valve springs are the right size and poundage.

21-05-2008, 17:38	#32
hawkeracing Briskodian Join Date: May 2008 Posts: 44 Thanks: 0 Thanked 2 Times in 2 Posts	Re: tuning advice Thanks for the replies....I dont absolutely have to have a cage as I will be running in road cars, but I would like one. I take it standard valve springs arent up to the job??

22-05-2008, 09:44	#33
KenONeill Briskodian Join Date: May 2006 Location: Normally somewhere in Scotland! Posts: 10,274 Thanks: 55 Thanked 481 Times in 473 Posts	Re: tuning advice With the Kent cam, and running 7_000 to 7_500 rpm, depending on whether or not the pushrods bend before the crank breaks, I'd think not. You've increased the valve lift and peak revs, so significantly increased the valve speeds and accelerations, which means you need heavier springs to control them.

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