Is the TU5 JP4S found in the c2 GT better?

23rd August 2010, 19:43

I know this has kind of been covered before but just wanted a little tiny detail. Apart from bigger inlet etc what else has the C2 GT engine got that the Saxo VTS engine doesn't?

Is there a lot of difference in performance between the two if i put one in my car. Been offered one for £300 with 29k so before i purchase my Tbs just wondering if its worth dumping this in and buying Tbs for that engine or wether its worth it.

Also mines cammed & mapped etc but can quite easily do it to the GT engine as i can get hold of them at quite a good price. Just wanna know wether its all worth doing?

Cheers

23rd August 2010, 19:45

All jp4 engines are the exact same, from what i've read swapping over j4 inlets to jp4 blocks, changing flwheels over, loom, sensors, not really worth it .. well apart from you get an engine with less than 100k which is a bonus.

23rd August 2010, 19:49

JP4S is what you find in the C2 VTS - has an alu inlet manifold, higher rev limit, 125bhp iirc.

The C2 GT has the normal JP4. Better off sticking with a J4 lump in the Saxo tbh.

23rd August 2010, 19:50

Quote:

Originally Posted by Krys_23

All jp4 engines are the exact same, from what i've read swapping over j4 inlets to jp4 blocks, changing flwheels over, loom, sensors, not really worth it .. well apart from you get an engine with less than 100k which is a bonus.

lol, very true. Mines at 91k, almost there. I might just get it as a spare then to be fair and carry on where i am.

Cheers mate

23rd August 2010, 19:55

Id only do it if I was going for sportier cams to take advantage of the larger valves.

Or if my engine was tired LOL

23rd August 2010, 19:56

The jp4s is in found in the c2 vts as leeumH said and swell as having the alu inlet it also has better cams with higher lift and duration over the normal jp4 found in the c2 gt and Vtr, which is why it has a higher rev limited and makes more power

Although the jp4s cams still arnt as good as the standard j4 cams from the saxo or 106

23rd August 2010, 19:56

its better to get your j4 engine rebuilt, too many things to swap over... but you do have a spare j4 engine so you have all the parts to do the conversion but it depends if you can do all the work your self and you have to drill the jp4 block to fit the j4 inlet, which i know i wouldnt be confident in doing lol

23rd August 2010, 19:59

Quote:

Originally Posted by jeffchiz

its better to get your j4 engine rebuilt, too many things to swap over... but you do have a spare j4 engine so you have all the parts to do the conversion but it depends if you can do all the work your self and you have to drill the jp4 block to fit the j4 inlet, which i know i wouldnt be confident in doing lol

My old vts, we swapped an engine overnight & got it running however swapping for a different unit plus everything else, with the loom, Box etc etc, i think id stall there so yeah thats taken on board. At least i know now so i can put that to the back of my mind

23rd August 2010, 19:59

Oh also cause the valve to piston clearance is so little on the jp4/jp4s engines the cam
Choice is quite poor

So I'd just stick with a j4 engine especially if you are going bodies then you can run better cams

23rd August 2010, 20:01

Quote:

Originally Posted by vtr_chris90

Oh also cause the valve to piston clearance is so little on the jp4/jp4s engines the cam
Choice is quite poor

So I'd just stick with a j4 engine especially if you are going bodies then you can run better cams

cheers man

23rd August 2010, 20:02

The JP4 has less piston/ valve clearance anyway, so not really any good for going down the camming route, unless you fit pocketed pistons. A few people have said Saxo cams don't sit central on the JP4 lifters too, so your cams would be no good.

How I see it:
If you want a low mileage engine to leave standard or boost (and don't mind drilling/ tapping holes for the inlet, butchering a J4 for the other parts you need) - JP4.
For high lift cams (to a point, i.e. 708's, PH3's) - J4.

23rd August 2010, 20:05

Quote:

Originally Posted by Princey_vts

My old vts, we swapped an engine overnight & got it running however swapping for a different unit plus everything else, with the loom, Box etc etc, i think id stall there so yeah thats taken on board. At least i know now so i can put that to the back of my mind

noooooo lol i dont mean swapping the engine, yea swapping the engine is easy i mean to many things to swap over from the j4 to the jp4 block, all the internals in the cylinder head need to be changed as well as the flywheel, sump, oil filter, a lot of sensors on the loom etc too much hassle imo lol

ill get you the guide

23rd August 2010, 20:07

http://www.saxperience.com/forum/sho...d.php?t=323539

23rd August 2010, 20:09

I'd just like to add.... Don't think that just cause a j4 block is reaching 100k it's on it's way out. Mines at 125k and still makes good power with just breathing mods. If it's been looked after it'll run forever (or till you stuff the car into something or a cam belt goes)

23rd August 2010, 20:09

Quote:

Originally Posted by jeffchiz

http://www.saxperience.com/forum/sho...d.php?t=323539

ooh sorry fella. Nice one, checking the guide now

23rd August 2010, 20:10

Quote:

Originally Posted by Alanapone

I'd just like to add.... Don't think that just cause a j4 block is reaching 100k it's on it's way out. Mines at 125k and still makes good power with just breathing mods. If it's been looked after it'll run forever (or till you stuff the car into something or a cam belt goes)

yer, i service her when needed and if something goes it gets replaced but too be honest my right foot is made out of lead to be fair. Its a cant resist thing in my car. The noise is like a viagra

23rd August 2010, 20:27

this is the adapter you need to use (i think) so you can use your original inlet manifold if you dont wanna swap the inlets over
http://www.gmcmotorsport.co.uk/index...roducts_id=236