Porsche 944 3L turbo

[Rob@Backyardracing]

A few Pics and boring small story that mite interest a few....

Well after today at Oulton park im pleased so far with this project ive been doing now for the last 4-5 years . Yes its taken a long time to do as its spent the last few years under a sheet in our workshop as we just didnt have time to carry it on due to our developments in the boxster/996 engines.

The car started life as a standard 2.5L turbo which imo are a laggy lazy car over a 3.0 16v S2 or 968, so we decided to build a 3L turbo to reduce turbo lag and try to make a better torque curve with only porsche OE parts and only out of what spares we had.

We started with a 968 bottom end due to its under spray bars and better tappered piston to suit boost, along with a swift machine to the tops. The head was ditched for the 944 2.7 head as this bolted direct on, the 2.5 needs mods to fit but is doable. 2.7 cam box/cam and all the aux etc is stock turbo parts, all simple and cheap.. (all this was done a good few years ago just before we put the sheet over it)

So recently i decided when i had a few spare days in the workshop to get this project finished, got the car running to find the head gasket leaking coolant so a swifted head gasket swap was needed then off to mapping with Wayne at Chip wizards for a good full day.. Top bloke and will be helping the Backyard team/Scoff tuning out next year with dyno time

Results where pretty good 350lb @4k rpm 100 over the stock turbo at same rpm..
Max of 300hp at 5krpm... the curve does then drop off due to a too small turbo but with the long ratio box and big band of torq it mite work ok.. (will try paste some graphs up)

Once this was complete i decide to book a track day and invite a few well known guys (one how races a 968) along to come and test the car and have a free day out . I was unsure how the car was going to handle so had to swiftly make some springs up and sort a pair of konis and sort the wheel geometry to suit the track.

Well test day came and went really well with some great respones from all the drivers and some excellent feed back.. Im chuffed its gone so well with no faults..

I only manged to take a few pics of the car and the old test drivers .. Should have a bullet cam vid soon..

What do you think?? It will be going up FORSALE soon

Now wheres my honda with some proper HP im sick of all this apex and balance crap....

[clee]

Love it
Proper driven wheels

[Big Steve - Raider]

Love that Car!!!

Would Love to own it!!

Don't fancy swapping it for a VAG Clio do you!?

[gtmatt]

Nice project mate car looks clean ,where my car is there is a breakers for them ,likevthe wheels on it ,I would of come today but the valver is still getting sprayed ,all good though any more plans for the 944 ?

[Rob@Backyardracing]

Cheers for the comments chaps, the car will be sold in time.. We want to generate cash for a dyno....

Would have been ideal for a ring trip i guess

[AlexS]

Interesting project.

Still time for a Ring trip. It's open weekdays in November. I'm over for 6 days next week.

[Rob@Backyardracing]

Well thought id stick some progress of this up on here. Over the winter months we have decide to convert the 3L 8V to 16V and keep the car a bit longer and also may look into a twin turbo option.. Long way off yet tho... After some thought and interest in the 3L conversions we thought we would try to convert the 2.5 block to a 3L by machining our own bores out and by make new liners from scratch. By doing this for peeps interested it would mean they dont have to go out to find a 968/S2 blocks that are costly and also the cooling jackets on the 2.5 are much deeper. The 68s and S2 have a habit of nipping the liners and seizing, and happens on a good few that get driven hard. With our design it will cool alot better.

First Pic below is of a stock S2 3L block, you can see how small the water jacket is.. The other pics showing are of a 2.5 turbo block we have machined out to house our liners...

[Rob@Backyardracing]

We then have made a liner up so we able to get a molding made up for casting a batch of liners. First pic is how they arrive back from the casters, this is a batch for the M96 engines which we do many of... We then have to machine and tidy these to a close tolerance before we then get them honed and plated then remachine for a perfect press fit.. The other pics of the new 3L liners, we just in the proccess of maching these down ready for plating and trail fit.. The side wall design has been made so we are able to flow the coolant the way we like it to be on our build also as you can see we have top suppurts...

This is how far we have got with this build.. long way to go yet but should be interesting to see done.. Ill add more up as i go along with this car..

[Big Jim]

Giving Darton a run for their money eh?

[Rob@Backyardracing]

Thought id post up this small vid of the car doing a lap Oulton Park, ignore the boffins talking ... currenlty sorting a piston design at the moment for the 16v conversion, will post more soon..

http://www.youtube.com/watch?v=wKuVWfM6wr4

[dave j gtt]

Beast

[Rob@Backyardracing]

Ok im a bit bored today so thought id take some pics of this project which hasnt really got very far due to all the time and development we put in to the newer boxster/996/997 engines etc etc...

So, firstly we picked up some nice H beam rods up as the stock 3L rods are prone to bend in boosted applications over 1 bar.. Secondly we wanted to get some custom pistons made up to suit our needs. So we had to get in touch with Wossner pistons. There is room in the bore to extend the skirts (help displace heat and give better surport), also we wanted the inner side of the piston modified and the thicker crown making up so we can machine them to suit a range or CR, prob from 7:1 up to 8.5:1. To do all this we had to draw up some designs for Wossner to copy for our needs and just had 12 pistons made up for now, (keep some as spares and customer engines in the future).. Once the pistons had arrived we could have the liners plated (nickel/sil) and final finish and make sure the bore is exact to what we need..

Also on the block you can see we have modified the channel where the water passes. On a stock block the temp difference is alot from one end to the other (direction of coolant flow) so basicly we have changed all this so the coolant on each bore will be the same temp throughout.. So now we are at a point where the bottom end can be built up in the near future..

The last picture here is a pic of a wossner piston we have had made up for all the m96 (boxster/996 etc) engines, you cant buy over size pistons for them. Yet again we have designed one and got wossner to make up a huge batch for us.. so now we are the first in the UK to supply and fit over size pistons on these, There is alot of other development work we have done to these engines which i really cant post up on a public forum..

So here is some piccys