Nufzed now Sumo with the Sprintex: Start and run

H

Hub280ZX

Well-Known Forum User
Hello from France!

The project took a little more time than expected, but the 280ZX 2 seater IMSA is now fitted with the Sprintex.
The original Emerald engine management was exchanged for the new K6 version, and the map programming has now started.

First video is the engine start from cold
http://www.youtube.com/watch?v=lyG1LVH374g

Second video is first road run... with still work to do, but running safe
http://www.youtube.com/watch?v=Vn3yUoIlYJ8

I am still looking for some tech data about the Sprintex. The actual Sprintex company in Australia has no information about the old UK initial versions. Some contacts in UK are giving no results until now.
The pulley ratio is just lower than 2, giving 11500 rpm on the sprintex for 6000 rpm on the engine. Pressure is now 5 psi. (Quite conservative, but we want to work safe!)
Any comments are wellcome!!:thumbs:
 
SeanDezart

SeanDezart

Well-Known Forum User
Any help as regards the UK Sprintex applications and tech specs would be welcome and I think that there is a name to give out in order to trace him - no ?
 
Rob Gaskin

Rob Gaskin

Treasurer
Staff member
Site Administrator
Very interesting.

The car looks and sounds lovely Hubert. The supercharger whine is a bit loud though, can you 'live' with that?
 
S

SKiddell

Well-Known Forum User
No such thing as a loud supercharger whine in my books, thats like saying "could you please quieten my V8 down as I find it annoying" :p:p:p
 
H

Hub280ZX

Well-Known Forum User
Thanks for your comments! I love the music! ;)
Yes it looks promising... but there is quite a long way to go and get the right boost, and the Emerald tuned!!
With the 5 psi that I now have, I am down from expectations around 8 psi.
The problem I have is no data about the Sprintex: Similar assemblies (with 80's/90's Sprintex very similar) on Ford V6 2.9L engines were reaching the 7/8 psi region but at what rotation speed?
The second question I have is: Why at 2500 engine rpm do I get the 5 psi... but no increase of boost as engine runs faster to 3500 rpm?
There is a bypass valve to free the supercharger on idle and vaccum in the inlet manifold, and the valve shuts when throttle opens. However I cannot see if this bypass valve stays shut or not when driving!! Maybe it does not shuts completely, or even re-opens for some reason...
I cannot imagine that the engine is eating all the pressure increase... but again... having no data...
So, the injectors are 420cc/min, calculated for 300 bhp.
Is the engine going to breathe and fill enough the cylinders with a stock cam?
Questions and experience to build!
 
AndyMinto

AndyMinto

Inactive
Hubert,
What compression ratio are you using? My turbo'd 280ZX runs at 7.4:1 and hits 7psi.
As for the extra revs, I may be wrong but does a supercharger not hit a max psi (due to the internal shape of the chamber) and after that the volume of air moved increases without increasing the pressure I think imho.
 
H

Hub280ZX

Well-Known Forum User
Hi Andy,
from what I know regarding the engine rebuilt by Mike Feeney, the pistons are turbo dished ones, the head seal is 2mm thick, and the compression ratio is down to 7.14:1
This gives a safe side for detonation risks, but of course lowers the engine capability for power.
Yes, the superchargers efficiency are limited with the rpm, but:
Reading about Sprintex implemented on ford V6 2.8 and 2.9L in the same period, I can see that they were hitting 7/8 psi. L28 being similar capacity, I cannot see why it could not reach similar figures. The volume generated at 14000 rpm is 475 cfm. There are lots of calculations to be made, but basically, the breathing of the engine is limited, hence the pressure built when you have more air brought to the inlet.
I am still looking for some curves drawing showing the volume pumping capacity of the Sprintex against rpm, but it looks like there are no documents... and the memory of users around 80's is gone!
Anyone with more data is wellcome: The exact model of the Sprintex is:
M110 / 91018 / S-1024-264
There was some data published on ford Sprintex users at:
2.9 Power Engineering Sprintex - XROC Bulletin Board
but due to old posts, the scans are lost and not more avaliable...
Asking Sprintex Australia, they do not have any data from the old UK manufactured ones!
Jaguar models have also used them for a while, but asking the specialised company named, they confirm that the memory of those units is also gone!!
AJ6 SUPERCHARGERS / AJ6 Engineering
Quite a number of users and information, but nothing that allows to really make a volume/pressure calculation!!
I have found even more interesting datas with a user having implemented a Sprintex on a VG30 datsun engine, but is this the same model, and are the calculations ok for an L28? (Click on the page if the reading is not ideal, and it will enlarge)
http://www.vondrachek.org/automotive/tech/screwed/picts/2to1_case_spreadsheet.jpg
http://www.vondrachek.org/automotive/tech/screwed/picts/1p45to1_case_spreadsheet.jpg
ManufacturerSprintex, division of AEC Inc.
Model S102Displacement~1100cc/revType Lysholm (screw) compressor
Internal Pressure Ratio~1.3:1 (4psi @ 1 atm)
Max rpm12,000 rpmLubrication
Rear bearings: Synthetic grease
Front gears: 75-90W gear oil
Size (WxHxL)8x6x16 (approx)
Weight35lbs empty

S102 seems quite close to the old version... but...??

This is where I am at the moment. :unsure:
 
H

Hub280ZX

Well-Known Forum User
Some update on the NufZed... supercharged!

No, the engine has not yet blown off! :p

I had a trip to Martin (February) to get the car back home in Reims, and as the management of the engine was not yet optimised, I rentend a car transport van, and drove it safely home.
The "reliability" is a long process, and beside the Ecu programming, there were a few issues I was not 100% confident to drive 600 km+...

First, I assumed that the Sprintex supercharger was full power at 14000 rpm. Martin had a change of pulleys and belt drive, so that fits with 6000 rpm on the engine. I now have a good 7/8 psi confirmed with 0.5 bar on the MAP sensor during boost runs.

Back home, the OEM fuel pump (Holley asiatic copy) was not my good choice (leaking!!). I changed it for a true blue Holley, and this one is tight! I then had to "rewire" the fuel pumps power supply, as the Holley + twin high pressure pumps were on the same wires... and melted a fuse, with very hot wires!! All done on that side.

The 100 amps alternator was also giving some trouble: The belt (plain type) did not stand the torque. I had a few destroyed rapidly... and that belt is also driving the water pump! Not good... To have a change with new multiple strips belt was not easy, considering the pulleys assembly on the crankshaft, with the ignition teeth wheel. Having no choice than keeping the standard V shaped pulleys, the change was made for a teeth shape belt, supposely standing more torque than the plain... Yes, true! No slip anymore, no heating of the belt, and no break, with full charging! Solved!

Then started the mapping game, with the "adaptive" function that offers the Emerald software...I have driven about 450 km now, with adjustments every 50/60 km. Basically, I try to optimize a "0 psi" type of map as classical Alpha-N management, and then, the MAP signal is used to make corrections to the injection and advance. Corrections are quite large, with - 40% injection time on negative MAP pressures down to -0.8 bar, and +50% injection time with pressures up to +0.5 bar. On this, you have all usual complementary corrections with battry voltage, air and coolant temperature, acceleration fueling, etc...
I am just about right from 2000 to 4500 rpm, looking at AFR values for the load range.
It is too rich down the range between 900 and 2000 rpm, and I have not yet pushed over 80% TPS, as my feeling from the data is that it is weakening up there...

A small video of the test yesterday morning?
Here it is for you!
I have a track session planned on the 1st of April on Pouilly en Auxois track. The track is small, with technical curves, and my target is more to learn about the handling of the car, that I cannot realistically test on the road. The rpm adjusted range should be OK there... but I will record the sessions to see what happens!

http://www.youtube.com/watch?v=Ur1v7MyXnuY


:driving:;)
 
H

Hub280ZX

Well-Known Forum User
Some news about the Nufzed?

The car was carried back home beginning of February... as the feeling to drive it 650km as a first road trip was not so....confident! I rented a car transporter, and drove it back with a few things still to insure like the alternator pulley correct tension... etc...

Of course, the engine management was still to improve, and that was the main reason to avoid the long drive.

I started the driving tests immediately back, and nearly every week-end was a step by step improvement with the understanding of issues: Map adjustments, accel fueling, boost corrections, advance map and corrections. The Lambda probe was there to help, and the data logger was a good tool to analyse situations.

Again, not knowing much or even anything at the start, it is a learning process that takes time. The car was improving step by step, until last week when I had the equivalent check to the UK MOT: Brakes fine, schocks fine, pollution fine!! No second visit required: Good news!!

The car was checked and ready enough to start the first track session in Pouilly en Auxois on the 1st of April. Still a little on the rich side for safety, and still not fully wild with the ignition advance somehow lowered. My intention was not to burn the tires, but to feel how the car was behaving on the track.

Discovery of the track, and progressively pushing to keep the right feeling. The engine was not tuned for WOT. I would estimate about 70/75% of the power avaliable, with puffs on strong acceleration... The car was pushed along the 20 minutes sessions... until on the fourth I had a smooth spin without damage: Found the limit, but it is far enough! The Wilwood six pistons on 280 mm diameter 32 millimeters thick vented disks are doing their good job on the front (I left some rubber signatures on the track), and the position 2 on schocks is also good.

The engine is boosted at 0.5 bar, and you can feel the torque from... idle I would say!!

Some pictures... and the participants came all with interested questions...
I have a complementary video from the inside, and a quick one from the track side... to come!

sumo2.jpg


rk0tvl.jpg


Pouilly Sumo 01.04.2012.wmv - YouTube
 
Rob Gaskin

Rob Gaskin

Treasurer
Staff member
Site Administrator
Hubert, I admire what you are doing with this car and how you are going about it.

However it sounds like a police car is following you with it's siren on !!!

To be honest I'm not keen on the 'look' either, give me your Capri anytime!

Good luck with the development and 'fine tuning'.

Are you taking it to Spa?
 
H

Hub280ZX

Well-Known Forum User
Rob,
thanks for your comments! At least it is on the tarmac again! :thumbs:

The Sprintex is the age of the car, and the sound of it is the generation of superchargers at that time. But it was more interesting to stick to something classic, instead of choosing a modern design that does not relates to the car's age...
There is space for a change with higher boosts... maybe sometime!

The look of it... tastes and colours are not to be discussed, they are facts! I like the bizzas, and believe me, there is a crowd around the car when it stops in the paddock!! A new bright race style paint will come, but this is the test year for now.
I have the same remarks here from the original screws and bolts defenders! ;)

Now that the test is done on a small low speed track, it's time to bring it to some more serious places, and Spa is another good step. Yes, the plans are to be there with it! My problem at the moment is that I will be in Prague the whole week, flying back on Thursday evening...Not sure I will be in due time for the Friday lunch session...

And there is still plenty of work to proceed with the tuning...
I stuck with Emerald as it was the original system with it, but I must admit that there is very few information around... compared with Megasquirt for example...at least on Datsuns and boosted systems...Feeling like a monk in his abbey, but looking forward to have a beer in Spa with you!! :cheers:
 
Mr.G

Mr.G

Club Member
Hubert, I really like the photos.

It's also nice to learn of the methodical approach you're putting into getting it to run right.

I think the car is a beauty, and the lines will always make it like marmite (either you love it or hate it) :).
 
H

Hub280ZX

Well-Known Forum User
I should have some more photos and videos quite soon...
The Sumo is going to have a few track sessions on the Spa track on 25/26 and 27 of May! ;)
 
H

Hub280ZX

Well-Known Forum User
So, the matter regarding maps is not so easy...

The Spa sessions were over rich, and I popped a supercharger tubing between intercooler and throttle. In fact I had another problem with the coils/drivers connections giving erratic sparks...
I only discovered this just before Dijon GPAO meeting and could solve the point with much difficulty to find the right connector... Opel/GM were ONLY quoting for a complete new wiring for the whole car!!
The drive to Dijon was 650 km on and back. I did it with the return under heavy rain. The car never let me down, however, I killed my first Lambda large band sensor... by plugging it with carbon black!!

I have a new sensor, but I need to have a better "start again" point, and the supercharger is messing the basic map as corrections cannot be done in closed loop.

Guys, I need some kind of basic map for injection timing or Volume Efficiency map, so that I can restart with this good base, and then only adjust the boost corrections from the manifold pressure.

The L28 is quite standard (280ZX 1980 n/a) with unmodified head, standard cam, standard skelettized inlet manifold, and 6 to one exhaust tubing.

Anyone having some data... (or the original mapping info from the datsun ECU?)
Thanks for help...:eek:
 
S

SKiddell

Well-Known Forum User
I can email you several Emerald maps for my 3 litre throttle bodied setup (and various incarnations)
Spark is quiet advanced (its running 12:1 compression with a good quench chamber) and may need backing off, fuel is strong for 293 HP so the map will need a lot of tweaking.

It would give you a starting point but the Emerald is very user friendly when setting up, as with most things practice pay off.

All of my mapping is done at Dave Walkers so we know they are good.

As for wiring, 99% of issues on home brew ECU retro fits are due to poor wiring, particularly on sensor, injector and coil pack terminals.

Wiring is a skill which most people just don't have.

Let me know if you need anything
 
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