Another thing I'm surprised nobody has brought up/hassled you with yet is using an 8v head. You've definitely improved over stock (with the port and cam). Just a natural question that comes up (you have to be fair) when you look at the total expenses and the lengths you are willing to go to gain power.

 

I think a 944 8v head will pull 200hp without any work done to it.
Just have to get a cam that works in the rev range required is all.

I did my various Dyno experiments and decided to stop when the standard early 944 cam seemed to be giving up the ghost - power curve totally flattened out past 5500rpm, peaking at 136whp in my car (stock internal US 9.5:1 early engine)
I would expect a 2.7 or 3.0 version of my setup to make more power proportional to the added displacement. I have no interest in swapping cams due to smog reasons as well as the expense. The late 944 NA cam would be worth at least 4HP over the early one but...a lot of work to swap cams for that kind of gain.

Adding a hotter cam should only help - the stock cam is pretty mild with 0 overlap.

 

He can fix that later with an S2 head and pistons if he wants, untouched it still outflows the ported 2.5 head by a pretty big margin.

 

What I presented was my interpretation of the data I found online and Augment is not connected to it except for the graphs mentioned. So if something is wrong then it is all on me and not on Tom.

Well, your stipulations sound good to me. The fact that the S2 comes out stronger than it officially was could:
- either show the limitations / accuracy of the predictions / maths,
- or the S2s were often stronger than claimed.

I'd say the first one is more likely, although the second is also not unheard of. (For example the Japanese limit of 280 ps was not always perfectly upheld.)

 

Bingo !

After all that Torque from so many..............!

Project 924Srr27L is Done, Dusted and Running..............and has been Rolling road Live mapped!

Check out the figures, Not just the BHP but the Torque...

And remember it's all running on 2.5L Stock parts:

- Bosch 1985 2.5 ECU
- Bosch Coil
- Bosch Distributor
- Stock Injectors
- Bosch A F M !!!

The mods / changes :
- Lindsey Racing stage II 2.5 Cylinder head (Inlets ported)
- Knife Edge Crank (6.5 Lbs weight loss)
- SPEC Aluminium Flywheel & Stage II Clutch
- 3.0 S2 Block
- 2707cc Capacity
- 968 Rods
- Wossner 105mm Pistons
- Webcam 274 Camshaft
- CR 10:9:1
- Extrude Hone Inlet manifold
- 1.4mm thinwall Exhaust (1 rear Silencer) 1.8" ID !
- 97 RON Fuel
- 20W50 Motul Classic Mineral Oil

8 hours of detailed Live Mapping from 1000 - 6000rpm by the UK's best.......Chip Wizards (Wayne Schofield)

See attached Spec sheet...............

R

 

I'll admit it, ~180 whp/wtq is a lot better that I expected. so, the lindsey stage II head + 274 cam + 228cc extra displacement + 1.4 points of compression + EH intake + custom dyno tune = + 40 whp/wtq over a stock 2.5 liter. I can't help but feel an S2 would have been a more appropriate choice. But, in a car as light as yours its faster than an S2 and probably about as fast as a stock 951. Nice work.

 

Yes, although this 924S originally had the detuned 150bhp 2.5 with a lower CR.

So the transformation from stock to now is as you'd expect quite dramatic from 150 to 205bhp, but even more so from the (550Lbs loss) from the original weight (2772 lbs) to (2222 Lbs).

The overall PTW Increase is over 60%

A twin cam head was mentioned to the mapper , but he said whilst a higher BHP figure would be achieved, it would not be as torquey and driveable as the 8 Valve that it has....

It surprises me that it's also the smaller valved 2.5 Head, and not the bigger valved 2.7 8v head, also I was concerned about the 2" Exhaust which I thought was the ID, but then found out it was the OD ! hence the actual inside diameter of the pipe is only 1.88" Inches!

I think for whatever reasons (i do not understand) that the bigger Inlet porting, faster and more slippery Inlet manifold (hone) have allowed more fuel and air In, and the exit and small bore (Faster gas velocity) exhaust have created great Torque low down and good BHP at 5799rpm and 190ft Lbs Torque at 2800rpm is excellent ..the 274 Cam mapped also plays a good part in all of this...

I dunno ? But i do know that the driveability on the street in a light car is so smooth, so easy and effortless....

Small amounts of throttle and short shifting at like 3000rpm seems to leave most cars for dead! not just off the lights but also from 25 - 75mph !

If one wants to give it more than half throttle, or even 3/4 in 2nd or 3rd it just flies.....

I didn;t want Lag (Turbo Engine) or a twin cam that needs to be would up the rpm range before really coming on.....and hence I'd now reccomend to anyone with a 2.5 8v to spend the money on fibre panels and go lightweight.

They could leave the motor, have a map and tune or maybe a camshaft but go light on the brakes, wheels suspension, interior and other parts...

It has a higher power to weight figure than any production transaxle, all the 924's inc 924Carerra GT, all the 944's inc both stock turbos, and also the 968.

It has taken however $35,000 so it's not and never was a light hearted project!

R

 

Congrats! I'll bet it's a great feeling to finally have everything up and running.

 

924srr27l,

Its nice to have you back on the board. I miss your posts. You have such great attention to detail & are much more willing to do the work, and spend money on your passion, then most of us.

Congrats on driving your dream car. I'm a fan of your amazing project... always have been.

Would like to see more photos of the finished project though

 

That's incredible!
Nice work!!

 

Yes and No !

It's been such a long time (3 year journey) since the car last hit the road, so it was more of an anti climax to be collecting the car last friday...

Then I wasn't too happy with the baptism as the journey home was a nightmare!

The heater was stuck on full, so I had both windows down but for some reason we must of had the hottest day here! So I was baking.....the car would not idle at all, as all the components were put together and the tune needed the idle mapped...

The gearshift came off in my hand and didn;t have the clip on it
The handbrake has not been connected I designed an inline hydraulic master cylinder cable operated and I need to modify the cable length to make it work properly...
I was stuck in a Huge traffic jam, with no idle, no handbrake and boiling and clutching the metal gearshift...attempting to crawl in 1st gear for an hour and stalling many times, the car was lumpy, hot, noisy and the whole day was made worst when I spotted I had an oil leak after parking up at service station!


The next day I went back to the engineer and we fixed the Oil leak and gearshift..

Then I ran in the car for 2 days and did 500 miles, then i drove to the mappers tuesday to get the tune and figures....

BTW it produced 179bhp on the 1st run ! it was running rich and lumpy and after the 8 hours 26 bhp was gained to the 205 bhp...but more importantly a crisp spot on air fule mixture figure was tuned for every increment from the idle to 6000rpm, which is why it took 8 hours! but well worth it...

Now i need to sort the handbrake, the stuck heater, the wipers don;t work or the washer jets, or the horn!

The front spring are too stiff @ 190 Lbs's and I need to fit aluminium NASCAR straps on my rear Lexan hatch as it goes "inwards" over 80mph!

All very trying and character building.....and also the brakes were poor to begin and after 500+ miles have now got a lot better to a point where they are very impressive (6 pot / 4 pot front & Rear) Wilwoods.

I guess there will always be teething niggles to sort, and I'll get on to them in time as my work is crazy busy at the Mo....

R

 

Thanks,











Decent Pics will follow soon, but I've neglected my work and business for the last week and need to get some serious work and cash in!

Then in 10 days I got a week off with the kids, so the pics will be a while as will be sorting out all the niggles...etc...

R

 

Thanks,

It's certainly provided a result which was never going to be a dead cert,
But i got lucky and found the right people that really know there stuff, like Lindsey Racing, and the Engine builder and mapper....

The rest of the car's spec compliments the powerful engine & Brakes and so its worked out to be a really good usable package for some Fun driving on the Street...

R

 

Congrats, you proved us all wrong on the power figures

Now we have a reference point for "how can I add power to my NA?" and the associated budget

 

I'm surprised how well the odd configuration has turned out, as I was well aware fitting a 3.0 block to a 2.5 head was not a common scenario, or was retaining all the Stock Ignition / ECU and AFM etc...but I think the Tuning Industry does concentrate too much on top end figures and often some products are not in reality all that are led to be.... Once the word gets round the street it tends to stick and become commonplace...

The mapper has spent 20+ years tuning 944 engines and you can imagine he's seen, heard, and fitted just about everything there is that's been made available over the years for road and race cars from many aftermarket companies...

This must be why he and the Engine man attempt to inform people that the stock system is very good and some changes are not that fruitional if at all....

The mapper could probably get another 10-20Bhp on top of the 205 but there would be adverse characteristics in the low and midrange RPM and probably unreliability also etc...

I spent a lot of my younger years Racing Shifter 2 stroke Karts and many moments of frustration trying to get the driveability good after chasing top power figures..My best lap times were always on engines with less power than the higher figure ones! because they were too erratic, and often undriveable....

From this I believe is what the tuners i have been involved with understand and they have certainly made an amazingly tactile quick classic car....

I' also didn;t want to have a 300bhp turbo engine, I'm not saying it would be boring and not fun..but I wanted a kinda Docile slugger with a lot of Instant "pull" and really drivable almost without having to shift to keep it on the boil...because like the 125cc Shifter Karts are raw quick and great fun, but only for 15 laps or so....otherwise your arms and neck falls off!

R