My 930 - 993tt engine project

JBL930 · 10-21-2009, 03:05 AM

I keep meaning to start a thread on here about my project but never seam to find the time. I thought i'd make a start now and keep adding to it when i can, otherwise i'll never get round to it.
As most of you know i'm most of the way through it now, but this may be of help to anyone thinking of doing the same thing.

Ok, this all started when I blew up my old engine, i was on a VMax day were we have a 2 mile runway and you take your car flat out. You accelerate for 1.5miles and have half a mile to slow down, it ends with a big earth bank so you want to make sure you can stop

I had done most of the common mods to the 930 engine

Heads and intake manifold ported
Injector blocks modified
964 cams
IA air intake
964t intercooler
K27HFS turbo
1.0bar wastegate spring
B&B style headers
Fabspeed duel out exhaust
IA fuel head
other bits and bobs

In addition to the above it had a new engine wiring harness, new alternator, rebuilt WUR to stock specs (i didn't know what i know now

), new piston rings, and a full engine/gearbox rebuild-reseal.
It had not been checked for even distribution of fuel to each cylinder, but i had an LM-1 installed so i could keep an eye on things. On my first run of the day it holed a piston, my friend holding the LM-1 couldn't read past the decimal point as it was flickering too quickly, so he was just telling me it was reading 12.something. There was no warning when it let go, just lots of smoke!!

I had a choice to make, do i go full Motec EFI and build a big single turbo beast, or fit a 993tt engine which has all the safety nets and also a huge "tuning package" market. I opted to buy a 993tt engine, and then the fun began...

spence88mph · 10-21-2009, 04:23 AM

Very subscribed! looking forward to hearing how it all came together.

slow&rusty · 10-21-2009, 04:26 AM

Quote:

Originally Posted by spence88mph

very subscribed! Looking forward to hearing how it all came together.

+1

JBL930 · 10-21-2009, 06:01 AM

Ok, so the hunt was on for a 993tt engine, the UK is only a small place so they don't come up often, but i managed to track one down. It came from a car that had been in a accident but i was told the engine was good.

I paid for it unseen and had it crated over to my mechanic, it turned out both turbos were shot, the right hand headers were bent, the cat pipe was also ruined, there was no airbox on the engine either.

I called the salvage yard people and managed to get a little money back, but not even 20% of the cost of the parts needed. I just took a deep breath and swallowed it, and instructed my chaps to get on with the installation and i'd get the bits sorted.

As far as installation goes fitting one of these engines in a 930 is far from straight forward, the first obstacle which is obvious is the placement of the oil tank, the 930 tank is in the way and had to go, we opted to fit a 993tt oil tank in the rear right wheel well and reroute the plumbing a bit

Then there was the issue about mounting the 993tt engine to a 930 4-speed box, the starters for either don't work with anything stock, so my guys played with all sorts of different ring gears and such and finally found something that worked, the engine came in and out 5 times for this, VERY time consuming! Would have been easier to go for a 5-speed from the start but i didn't have the budget for the RSR suspension at the time so we had to make do!

wjfk32 · 10-21-2009, 06:25 AM

Greetings...

sorry, for your 930 engine..........................

On the other side, what type of turbos are you considering 24/18 etc.. very interested..

Wish u well!!

Walt

juicersr · juicersr's Garage

Great work so far. Also interested in the turbos u have considered.

lucittm · lucittm's Garage

Do you still have the original 930 engine? Some of the bits could help you finance your project.

Mark

JBL930 · 07:22 AM

EDIT: To answer some questions

I wanted originally to go for K24/26RS turbos, but was talked into using K16/24's by the guy i was using for the mapping, i will cover this in a little while. This project is well over a year old and the car has been running for a while, albeit as you will see with some set backs!!
The 930 engine is being rebuilt and i will either sell it, or put it in a really light narrow body 964 and use it as a track whore??

Back to the tail...

I have no idea about wiring, i can only assume it was a nightmare to hook up a modern wiring harness to an old car but my guys just got on with it and everything in that department went well.

The next hurdle was deciding on a rear tail, i desperately wanted to keep the stock 930 silhouette but was told the tail simply wouldn't fit

After lots of chopping and welding, shuffling things about a bit, they managed to "just" make it work, and i mean JUST. But i was happy, i've lost the damper for the tail so i have to prop it open, and the intercooler touches the back of the tail slightly but it closes and that's good enough! Also the right hand hinge goes through the dirty side of the airbox, but i'm thinking of a new way of getting nice cold air in there anyway, future project.

Whilst they were working on the engine we found out that it had some work done on it before, the hydraulic tappets were removed and manual ones fitted, same as the GT2 Evo engines

It also has 993 3.8 RS cams fitted, it turns out the previous owner had the RS Tuning 520bhp kit fitted with K24/26RS turbos, but he had gone to many other turners after this who all promised the earth power wise and never delivered, the only thing remaining on the engine from that kit was the cams, stronger rod bolts and head studs and the cam sprockets. The 993tt engine in stock form has friction fit cam sprockets, these are prone to slipping so retro fitting 964 style ones with the locating pin is the way forward.

JBL930 · 10-21-2009, 07:35 AM

Then we had to think about extra oil cooling, i didn't want to change too far from the stock look so fitting a bigger front spoiler was not what i wanted, as the aircon was already ripped out i decided to fit a Setrab unit in the place of the front aircon condensor, i fitted a new fan there too to drag air over it to aid with cooling as it isn't directly in the airflow under the car

Everything was in place now for the engine to go in and i ordered up a pair of K16/24's from Fearnsport in the UK as i had decided to use them for the tuning, they had looked after the engine for the previous owner so it seamed logical to use the same people.

I also played with the idea of fitting a bigger intercooler, there is one design that has been doing the rounds for years offered by companies like FVD, i tried it on the car and it would have never fitted with the stock tail.

Also after some digging it turns out they perform worse than the stock unit, so i'm sticking with stock for now.

JBL930 · 10-21-2009, 07:56 AM

We had no space in the back to fit any "off the shelf" mufflers, i had managed to buy a pair of stock cat pipes, i had them cut open and the stock cats removed, and decided to try it like it was with no cats and no mufflers.

So we get the engine in the car and it runs, obviously very excited at this point, this whole thing has taken probably 8 months or so thus far. The car is running badly with the ECU that the engine came with, so my guys who fitted the engine (Northways in Reading) had a spare stock ECU lying around and i used that to drive the car up to Fearnsport. It's only boosting to 0.5bar at this point so something is wrong

A couple of pics of the engine in place

These tips didn't stay on the car, they are all that the guys had lying around

SOUND CLIP WITH NO CAT AND NO MUFFLERS

Fearnsport tell me they want to have Cats in there so i order a pair of 100cell ones from Germany and they have them welded in the stock pipes.

They have the car there for quite a while, trying different maps and not being able to get rid of an overboost issue. It only seams to be an issue when at wide open throttle going between 3rd and 4th gear. They blame this on the tall gearing and tell me there is nothing they can do, i'm obviously perplexed!

I collect the car and it's not right, it's quick but something is wrong. I get the car back to Northways after a week or so and they put the diagnostic equipment on there, is has faults from two of the four oxygen sensors, there is an fault with the MAF sensor too, and i think it's prudent to get a new N75 valve and new wastegate actuators as the ones we'd used were on the original old turbos.
We get all this stuff on the car and it's behaving totally different, so i take it back up to Fearnsport to get tweaked. They have it for a while and convince me to fit new BOV's as they don't trust stock ones, so they fit a pair of second hand ones they have lying around

And i'm told it will be ready for Le Mans (this is last year). I pick the car up and it's running much better, boosting to 1.1bar and holding steady, the reason for the overboost before was badly adjusted wastegate actuators, i had to fault find that BTW, you'd think it was rudimentary to check these things before mapping, right?

Ok, so i set off down the road in convoy with my mates heading off for Le Mans, i get 4 miles down the road and smoke everywhere!!! No boost either... I thought the engine had blown up!

I get my guys at Northway to come and collect the car fro the road side and i relegate myself to driving my old bimmer down, with a very long face as you can imagine.......

As you can imagine the bills are mounting

wjfk32 · 10-21-2009, 08:12 AM

Greetings:

FANTASTIC!!!!!

Looks like u r going 16/24 route...What I've read from the alot of 993T forums that the 24/18 was the way to go...They mention Todd.-Promotive has a great set-up...
Have u considered this route..I know it proabably doesn't make sense being on the other side of the pond..
I believe one guy-has todd's 993 set-up with a 3.8..No joke..Can't remember his is avatar but he sometimes chimes in on 6speedonline.

Well, best of luck!!!! I'm sure it will shine!!! no matter what u do.

Walt

JBL930 · 10-21-2009, 08:42 AM

Hi Walt

I've heard of people using the 18g compressor wheel and it seams to work well. I will be buying a set of K24/26RS turbos next though, along with the 520bhp RS Tuning ECU, everything else is in place for this.

The beauty of the RS Tuning kit is that it is tuned with headroom, basically it is proper Porsche HP. A lot of tuners out there map for peak power, that is fine if you live somewhere that the temperature never changes and it is mapped for that environment. But here in Europe it can range from -10 to +35 so the ECU needs to be able to compensate. The way Motronic works with the MAF sensor is, it senses the ambient temperature of the air, along with the air mass that the engine is ingesting at a given throttle position and RPM point. Colder air is denser therefore it doesn't need as much actual boost pressure to reach the air mass target, warmer air will require more boost to reach the same air mass target. Porsche and RS Tuning (and Ruf) map the car on the engine dyno to produce the exact same power in every condition. Whether i'm driving through the alps or in southern Spain, it will give me exactly 520bhp, even if i am absolutely flat out down a German Autobahn on a blistering hot day for hours on end, the engine will work within it's safety limits and deliver the same power. I don't doubt on a warm day the engine could handle 560+bhp or whatever with those big turbos, but as soon as the temperature drops and the air gets denser the ECU would have to be pulling timing and boost. This, in my opinion, is undesirable. I would rather have a properly tuned and tested package, done on an engine dyno, by the best in the business, guys that have tested their packages on engines to destruction, they know exactly what the stock bottom end can handle, what head temps, IAT, boost level at a given ambient temp etc etc etc... It's a no BS properly assembled and tested package!

The map that Fearnsport put in the car would run great on a normal day, no problems. As soon as it got cold outside and you put your foot down it would stutter, you could feel the ECU cutting ignition and boost, too much air mass. Basically it's only mapped for one weather condition, and was aiming for peak numbers. I'm currently running with a 490bhp RS tuning ECU in the car and it works well, but i'll come to that

9dreizig · 10-21-2009, 08:47 AM

Subscribing!!! Nice butt on that thing btw ( the car of course haha)

JBL930 · 01:42 AM

Carrying on with my story (for those that can be bothered to read all this...)

It turns out that the diverter valves (BOV's) were faulty, basically they didn't open on vacuum and this caused the right hand turbo to stall. The stall stopped the cold side of the turbo spinning whilst the hot side kept spinning, the nut came off the end of the shaft and the turbo fell apart internally. The left hand turbo kept spooling, and as they share the same air intake it managed to suck the nut all the way around the intake and into itself destroying the left hand turbo too! Oh Joy............

I needed two new turbos and one new 100cell cat. I learnt that even RS Tuning use the stock diverter valves, so i bought two new stock valves and had them fitted.

I picked the car up from Fearnsport again and it seamed to run ok, i was getting some quite good 60-130mph times, ranging from 7.53 seconds to 7.8 seconds which is pretty rapid for an old car, pretty much identical to a CGT, and only fractions of a second slower than an Enzo

The back of the car was squatting badly, sometimes when you got grip you'd be staring at the sky, not good, so i bought the RSR suspension package from Rebel Racing and got my guys at Northway to fit it

I went with the through chassis sway bar, this is a bugger to fit

Thought it prudent to have a strut brace too

The car handled much better but was still a bit soft in the rear, i've since fitted 600lb springs in the back but haven't had much time to test it as this was only done recently.

I had the car dyno'd and it showed around 500bhp, the boost was nice a steady and the fuel looked good too. There is a slight blip as boost comes in but it doesn't do this on the road, it must be as the rollers are loading up or something?

DYNO RUN CLIP

I took the car on another VMax day, this time with no drama, thank God!! It performed well to be fair, it kept a nice straight line, didn't wander too much above 180mph, it all felt rather good!

FIRST RUN 183mph This is me against a 430 Scud, i let him go when we went around the corner, it was my first run and i wanted to make sure i had plenty of space if anything went wrong

A run up to 187.4mph

A run showing lateral and long G

I was almost at the rev limit with the 187.4mph run, i needed bigger wheels or longer gears. I have had a set of Big Red brakes in a box for a while and to fit them i had to ditch the stock Fuchs, so i've been holding out for a set of Ruf classics for what seams like forever, i finally found some........

Reaper930 · 10-21-2009, 10:25 AM

Jonathan, great read, please keep up the posting

its nice to see you finally dedicated a thread to telling the story

JBL930 · 10-21-2009, 11:30 AM

Quote:

Originally Posted by Reaper930

Jonathan, great read, please keep up the posting

its nice to see you finally dedicated a thread to telling the story

Cheers Gabe, it was well over due having a thread on here, just never had the time. I'm tied up this evening so will carry on tomorrow

wjfk32 · 10-21-2009, 11:49 AM

JBL..

WOW!!! GREAT MOTRONIC SYS...

What type of gearbox--Can't open up the video...work does not permit me..ahhh!!!

Congrats!!

Walt

JBL930 · 12:06 PM

Quote:

Originally Posted by wjfk32

JBL..

WOW!!! GREAT MOTRONIC SYS...

What type of gearbox--Can't open up the video...work does not permit me..ahhh!!!

Congrats!!

Walt

Hi Walt

Stock 993tt Motronic is MAF based (i think even 996 and 997 is too), they all do the same thing. That is what makes them so difficult to map properly. There are plenty of people who know how to play with the map, but very few that can map it "correctly". It's designed to compensate, to allow for different conditions, to vary boost and keep within set air mass targets.

Most aftermarket tuners set them up for fixed boost, they fit stronger wastegate actuators, and an EBC, then they map the ECU to allow enough fuel and ignition to give max numbers for the preset boost level. This is fine for a race car, or for a car that is always run in the same ambient temps.
However, you loose the safety of the ECU being able to pull boost to save the engine, you can only rely on it pulling timing or cutting spark all together if it senses danger. Not good for longevity, or for anything mainly used on the road IMO

The gearbox is a stock 930 4-speed box at the moment, it works well at this power level if i'm honest, i'm in no rush to go 5 speed but no doubt will at some point

wjfk32 · 10-21-2009, 12:17 PM

JBL.

Enjoy it!!!!..JUST-. Keep your eyes OPEN for a 5speed gearbox. I believe it would make your machine with a wider powerband..I'm sure you have driven similar set-ups like yours with a 5spd.

Great stuff!!!

Walt

DDDD · 10-21-2009, 01:50 PM

Nice video, great project!