205 GTI Sprint Car - Way forward

neilc

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As a regular browser of the Peugeot Forum I have noticed a lot of information has been disseminated there



My Peugeot 205 GTI I currently used for sprints has a DKZ head on DFZ block as was recommended the Peugeot Forum resulting in the engine producing a 131hp on a hub dyno. I was quite pleased with the results.

I used the cam that came with the DKZ head. The head was only skimmed and a 3 angle cut done on valve seats

To upgrade further I would like to do the following:



  • After market ECU – I have a Megasquirt II
  • Adjustable cam pulley I thought I would purchase B M Baker one?
  • Cam to be used from what I have read is dependent on whether the original inlet manifold is kept or not.
  • What cam do you recommend if I keep the original Inlet Manifold? What expected output
  • What cam would be recommended if I use Jenvey throttle bodies or some other brand? What is the expected output. What company is the best source for these throttle bodies?
I could get the camshaft made locally (Brisbane) by Tighe Engineering not sure of cost yet, it could be a good solution depending on cost as I eliminate air freight from UK and also eliminate the exchange rate between UK and AUD



What other factors do I need to consider? Should I do the sump mod shown on Taylor Engineering website? I currently have the DFZ sump on the engine.

I would appreciate any comments that you are able to provide
 
I don't think BakerBM do vernier's anymore as I was recently looking into these.

Tighe recently reground my DFZ cam for $340 and had it done in a couple of days. He doesn't stock blanks so you would still be paying his cost to buy a blank from Turkey, unless you are going down the billet route. Happy to share my grind, however best speak to PeterT as mine was as far as I could go with the pitiful meat I had on my cam.
 
You camshaft choice is limited by two factors:
1. Material Available - A DFZ cam can only be ground to approx. 237º @ 0.050" and 0.425" max lift, otherwise the shims become excessively thick. The DKZ cam has a bigger lobe on the inlet, so you have more freedom there. However, the exhaust lobe is the same as the DFZ, thus the same applies. You could have a "dual pattern" grind, where the inlet and exhaust differ, but you'll pay for two setups. This is the best solution for a DKZ cam, otherwise you're grinding away valuable lift on the inlet. Thus you could have approx. 240º @ 0.050" and up to 0.450" lift on the inlet. Or more duration and similar lift. eg 248º @ 0.050" and 0.425" lift.

2. ECU/Manifold - the standard inlet isn't so much the restriction, but the AFM and thus the ECU. Changing to an aftermarket ECU and mapping fuel via TPS, allows you to remove the AFM. Reversion pulses from more camshaft overlap upset the AFM. You can run the standard inlet with the PTS7048 max torque cam for example, which has 295º advertised duration and 251º @ 0.050". If you have 11:1, this would be suitable. If in Qld, talk to Tighe. If in Melbourne talk to Crow.

Make sure you set the valve seat spring pressures correctly, regardless. If you do choose an aftermarket cam from Catcams etc., make sure you check for spring bind if lift is more than 0.460" You may need double springs.

You'll need a vernier pulley regardless of cam choice, unless you're handy with a lathe.
 
Thanks Peter I will give your comments some thought and possibly have some more questions
 
I am endeavouring to work out compression ratio of my engine, I have used the following figures I have managed to find on various forums
Bore 83mm
Stroke 84mm
Gasket diameter 84 mm
Gasket thickness (standard) I allowed 1.5 mm not sure of thickness compressed
Piston dish 9cc (dfz pistons)
Combustion chamber volume 30cc (dkz head lightly skimmed)

Works out around 11:1

Any comments?


Been researching adjustable cam pulleys there seems to be on 3 manufacturers I could find
Piper
cat Cams
kent

Anyone make a recommendation? BM Baker one no longer available
 
Hello Peter not sure I follow you post.
Can you comment on my assumptions for calculating CR?
 
I am endeavouring to work out compression ratio of my engine, I have used the following figures I have managed to find on various forums
Bore 83mm
Stroke 84mm
Gasket diameter 84 mm
Gasket thickness (standard) I allowed 1.5 mm not sure of thickness compressed
Piston dish 9cc (dfz pistons)
Combustion chamber volume 30cc (dkz head lightly skimmed)

Works out around 11:1

Any comments?


Been researching adjustable cam pulleys there seems to be on 3 manufacturers I could find
Piper
cat Cams
kent

Anyone make a recommendation? BM Baker one no longer available
Stroke 84mm. No 88mm
 
Recently I went to Tighe Cams gave them the info I had on the PTS7048 cam and chap there came up with 4 options which I have attached to this post. I was wondering if someone (PeterT) can help select the correct one to run with a DFZ block with a DKZ head. Standard induction system I will have an after market ECU and adjustable cam pulley by the time the cam is made. If none of these profile are any good also advise and I will go back to see them.
 

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Probably that first one, with 252 deg and 0.448 lift. I’d also fit a thinner head gasket to get near 11.5:1.
 
0.014" lash will be noisy. Ask them about 0.010"/0.012". That will increase the duration as well.
 
I have a Payton head gasket that is 1.2 mm thick is that thin enough or should I try for something smaller?
 
I was thinking 1mm copper. There is also a 0.7mm Cometic or copper available.
 
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