Fixing Power Curve

[Daniel306 12 1 Cars]

 

Bought a Gti today but the power curve is not to good, Its a 406 sri botom end with a 1900 8v head and a turbo technics manifold with i think a Gt28 turbo, its running a emerald ecu with 3 maps

 

Anyone got any ideas how i can make the power stay longer? this is one of the first petrol engines iv owned

 

 

[welshpug 1,661]

add more valves or less capacity.

[dcc 855]

nice torque figures

[Daniel306 12 1 Cars]

What head would be better to fit to this without changing everything else?

[Daniel306 12 1 Cars]

Could i get this one ported and polished? and then possibly fit a better turbo

[Paul_13 212 1 Cars]

Didn't the head gasket need replacing?

[Daniel306 12 1 Cars]

Yes, the head is off now waiting to be skimmed but i may pollish it while its off

[Paul_13 212 1 Cars]

Ah fair enough. Best of luck

[Daniel306 12 1 Cars]

Got a choice of cams here that could be fitted, standard, 1900 Gti or a PT36. think iv also got a piper cam somewhere

[Anthony 1,003]

Any idea why it's running a 1.9 8v head?

 

Seems an odd choice when it has smaller valves and doesn't flow as well as the 2.0 8v head. Not only that, but I would have thought that the resulting compression ratio would be a bit on the high side as well, atleast judging by the amount that you need to skim from a 2.0 head when fitting it to a 1.9 bottom end in order to raise the compression to something sensible.

 

Cam wise, I know that the standard 2.0 turbo cam is very mild. A DKZ (1.9 GTi CAT) cam I believe is the best standard cam to use, but a 1.9 GTi one should work well and help top end a little.

 

Still, whilst the power delivery looks distinctly diesel-like, those are some pretty impressive power/torque figures!

[Daniel306 12 1 Cars]

As it turns out the ports are pear shaped making me think it is the 2.0 head. Got place near me that is going to pollish the ports and match the inlet better.

 

Iv read that the KCPT36 cam is almost the same, I do have a 1.9 cam but I dont think it has CAT stamped on it

[Anthony 1,003]

That would make more sense. 2.0 head with a 1.9 inlet I'm assuming, hence the port shape mismatch?

[Daniel306 12 1 Cars]

1.9 inlet, it has had a poor attempt at matching them up, rush job or something. they are in the shop now getting the head skimmed, matched up and iv asked if he would polish them

[NFS 32]

so whats the benifit of havingg the 1.9 inlet on the 2.0 head? better throttole postioning? flow?

[sub205 5]

At least the non-turbo-manifold of the 2.0 8v does not fit under the bonnet. Thats why i used a modified xu9-inlet for my XSI-Engine. The turbo-manifold however fits nicely.

[FireFly 4]

This same one over on 306oc?

[Jolly Green Monster 51 1 Cars]

Head gasket issues wouldnt help

 

Looks possibly retarded timing wise?