TU5JP4 Turbo Build - Saxperience

1cobrav8 · 6th August 2013, 19:49

Hi guys just thought I start a thread for my turbo build. Doing things a little different to most in the way that I don't own a car yet....only and engine lol. Wanted to create something with big BHP again. I've previously built a magazine featured c20let corsa but now thought it was time I build a quick French car. A fair few years back now I had a stripped out Saxo VTS with a gmc supercharger kit and that felt pretty quick back then but i'm now after something even quicker.

Rough plan so far is to build the motor and then map and dyno test it on my dads engine dyno - this should provide some interesting real crank horsepower figures as I know 99% of previous builds have al just been mapped on rolling roads from what I can see. Bear with my on this thread as its still early days and my options and decisions change daily lol.

Target bhp is 350-400. Did want to go more but I've been ready the issues some guys start to get with clutches and gearboxes etc and I'm not sure a have the patients or time for that lol.

1cobrav8 · 6th August 2013, 20:02

Starting point, std TU5JP4.....

Sump removed to weld in turbo drain...

Cam belt covers removed....

Throttle bodies and start of the plenum...

Plenum in situ....

1cobrav8 · 6th August 2013, 20:10

Found out the hard way that the stud arrangement is slightly different on the jp4 engine when my manifold arrived yesterday....new one currently now being made...

Jenveys fit the manifold perfectly

...

Fuel rail and injectors in(they will need upgrading before I can add to much boost)...

Replacement compressor housing with 3"inlet 2" outlet...

Originally I was going to put it on the dyno as a std engine to get a base map and see what power I can take it to just for interest really but now im thinking just pull it apart once the fab is done and build it properly...

Grimey · 6th August 2013, 20:55

Looks like a good build your starting, certainly one to keep an eye on. Presuming this is going in a Saxo?

Not sure if you have seen this thread but it's a must read for fitting a JP4 engine in a Saxo and might give you some extra pointers.

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

Ross^p · 6th August 2013, 21:55

350-400 is perfectly achievable - will be interesting to see how you get on.

The MA gearbox barely copes with standard power - anywhere near your target and you'll be needing to go BE gearbox anyway, so don't hold back on the power because of that.

1cobrav8 · 6th August 2013, 22:29

Quote:

Originally Posted by Grimey

Looks like a good build your starting, certainly one to keep an eye on. Presuming this is going in a Saxo?

Not sure if you have seen this thread but it's a must read for fitting a JP4 engine in a Saxo and might give you some extra pointers.

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

Cheers, this will be really helpful. Been a bit worried about the differences and whether to just buy TU5JP engine before starting the actual engine work. Read that the jp4's have weaker valve springs etc, so they will need upgrading when I fit the cams. Also noticed tonight that you can no longer take the turbo oil feed from the side of the head so I'm now looking at tapping into the oil gallery at the front of the block.

Any help suggestions and advice along the way will be greatly appreciated guys

.

1cobrav8 · 6th August 2013, 22:34

Quote:

Originally Posted by Ross

350-400 is perfectly achievable - will be interesting to see how you get on.

The MA gearbox barely copes with standard power - anywhere near your target and you'll be needing to go BE gearbox anyway, so don't hold back on the power because of that.

Yer I totally agree that a BE box is the only way. How reliable are they over the 400 mark? Surely even they must start to struggle to cope after that point along with the clutch? I was considering fitting the 1800cc stroker kit to aid lower down torque and quick spool but am concerned the extra torque could again kill the gearbox and clutch?!

Anyone had any experience with the stroker kit offered by spoox?

Ross^p · 6th August 2013, 23:26

I don't think the stroker kit pound for pound is good value in my opinion but... It's your money

Ps - you can still take the oil feed from the side of the head - just remove the ball bearing and tap to suit. If that's your thing.

dannygti · 6th August 2013, 23:31

If I was building another turbo 16v I'd be stroking it to 1800 (just under so you don't have to use 80mm pistons)
Obvious upsides is you have more torque off boost/on boost better spool capability etc.
Downsides is too much torque low down.

I'd love for someone to come up with a proper solution to the chocolate gearbox's.

1cobrav8 · 7th August 2013, 07:05

Quote:

Originally Posted by dannygti

If I was building another turbo 16v I'd be stroking it to 1800 (just under so you don't have to use 80mm pistons)
Obvious upsides is you have more torque off boost/on boost better spool capability etc.
Downsides is too much torque low down.

I'd love for someone to come up with a proper solution to the chocolate gearbox's.

Yer that was my thinking behind it though it would have to be worth it to justify the extra £1000-1200 depending if you have it rebored to 80mm. Extra low down torque could be reduced by giving more low down cam overlap - just moving the power further up the rev range. Though then if i end up revving it more im going to need stiffer valve springs etc depending on my chosen cams. Lots to decide upon lol. Would just be nice to build something slightly different to things that have already been done.

dannygti · 7th August 2013, 09:59

Quote:

Originally Posted by 1cobrav8

Yer that was my thinking behind it though it would have to be worth it to justify the extra £1000-1200 depending if you have it rebored to 80mm. Extra low down torque could be reduced by giving more low down cam overlap - just moving the power further up the rev range. Though then if i end up revving it more im going to need stiffer valve springs etc depending on my chosen cams. Lots to decide upon lol. Would just be nice to build something slightly different to things that have already been done.

That's defeating the object a little, if your going to rev it then leave it 1600, if you are going to stroke it then rev it I'm worried the piston speed maybe a problem. The best answer is to sort a proper gearbox out then you have a LOT less to worry about.