F40 Boost loss question

This is why I have been working on a computer controled, cockpit adjustable wastegate control. Prototype is now installed and working in JohnnyFerrari's car, and the final bugs worked out this spring after the car is out of the paint shop. I have found there is a good bit more "un-tapped" fun there without exceeding the factory boost levels. Also nearing completion on a MoTec type injection / ignition system for those that want to take it to a new level.
Dave

 

Thats a very impressive gain of power for a few turns of a screw!

However, the gain might have something to do with the LM turbos and different ECU though. It would interesting to see what would happen to a standard car without the modifications you have.

 

I left the printouts in my car (I'll try and get time to scan them today) but I remember we calced the engine HP at just above 505 assuming a 15% drivetrain loss, so I believe we were at 430 at the wheels.

I was mistaken on the dyno brand, btw. It was a Mustang Dyno. Also, these guys tune a lot of turbo cars there for the import racer crowd, but the laws of induction and boost are pretty much the same regardless of marque, so a lot of what he suggested carried some weight with me on the F40. He suggested replacing the Bosch blow-off valves (which he said will degrade over time) with ones built by Forge Motorsport. I guess I can call Forge and give them the Bosch part number and they can provide the replacement. Anyone used any of their stuff before?

http://www.forgemotorsport.com/

He also said if I REALLY wanted to get trick, I could install a water misting system to spray microparticles of water over the intercoolers at high boost to induct cooler denser air. That's more mod than I want to do, but I am thinking about the valves...

 

i think you'll find that the amal valve (boost contol valve) bleeds off air too the wastegate to gain higher boost,, this valve is operated by PWM output from the ecu (pulse width modulation) when this is set too 0% the boost will be running the lowest it can!

wastegate control valves can wear with time, as they are only a spring and a diaphram

as for wastegate preload this must be carefully adjusted and not just a couple of turns here,, a couple of turns there! this is because this will alter your boost curve all over the rev range,, maybe to rpm/load sites which havent been mapped! which is a big no no you can do with preload of the wastegate with a pump and pressure gauge!

as for blow off valves,, here in the UK we call them dump valves normally, forge motorpsort will be able to help you out,,,

after all that i would like to say that i have never worked on a F40 personally,, but i have worked on cars with the same ecus (ford escort cosworths,, which have the same amal boost control valves)

thanks for reading

 

i wouldnt bother,, the results will be tiny

 

Thank you for the input. That was also my conclusion. But you do think replacing the dump valves would have any effect on performance? Or just be a preventative maintenance "upgrade" ?

 

Dump valve= Wastegate

just wondering wouldn't a aftermarket wastegate from companies like HKS, Greddy, or even Tial be better controlled then the wrench controlled one originally on the Ferrari.......I know you can get a Boost controller from anyone of these companies that have a brain built in that can adjust boost on the fly from the cockpit and be preprogrammed to change with the RPMs automatically ......would be safer for your vehicle, god forbid your spring got stuck, than one that can not be monitored. I know HKS has different PSI springs that can be installed in their WASTEGATES.....these digital boost controllers monitor boost at the same time throughout the RPM range less chance of boost creep, and less chance that you will also loose boost at a critical time.....like when you want to lay the rubber on the tarmac

 

Again: no

Dumpvalve is on the engine-inlet side of the turbo, the wastegate is on the engine-exhaust side. The dumpvalve is intended to 'dump' excess pressure in the engine inlet, the moment you take your foot of the accelerator (to shift gears, or to brake). If this pressure was not released, it would back-pressure the turbo's compressor resulting in unwanted spooldown(which in turn causes an increase in turbo-lag).
The wastegate is a 'gate' that opens when enough turbo-pressure (or boost) is sensed. When it opens, it directs exhaust gasses past (not through) the turbo's turbine. In effect these gasses then bypass the turbo alltogether. In some cars, this wastegate is adjustable from the driver's seat. Maximum turboboost can then be adjusted.

 

Ok - then I mispoke. I should have said blow-off valves, not dump valves, right? Are they smaller valves (made by Bosch) which are about 4 inches long and cylindrical, wrapped in silver foil? The tech said they were wear items, and that I should look into replacing them with ones from Forge.

I have also thought about a completely separate wastegate control system that is solenoid controlled rather than with a spring. Anyone in here experimented with this on an F40 before? Sounds like a fun winter project!

 

Hmm... ok. Maybe I DIDN'T mispeak then.

 

Steve, I was actually quoting MAHOOL. A blow-off valve in the US is the same as a dumpvalve in Europe. But a wastegate is something else, which bot triXXXter and I have tried to explain.
Apart from that, this is a very interesting thread I think. Steve, it would be interesting (like you said in your other F40 DYNO thread) to have another F40 to compare DYNO results with. It seems that not all Dyno's collect information the same way? Good luck!

 

i would stear clear of indepent boost controllers as these are taking away one of the fuctions of the ecu, the P8 ecu int he f40 can run closed loop boost control (not sure if it does though) what this does is "look after" its boost curve,,, would you add a controller on which controlls spark-no,, so dont take away tis boost control

Gareth

 

actually they do have a spark controllers, but the reason for my statement, not getting to technical, if a Tubi exhaust causes fluctuations in boost that can affect performance, maybe the on board wastegate computer may not be able to handle it and may need a stand alone boost controller. it would be more advantageous to the F40 LM driver or the one that has upgraded turbos that tends to drive hard. the factory comp might not be able to handle upgraded engine hardware......plus the newer boost controllers as well as the fuel controllers are better then the ones made 15 years ago be it factory units.....like comparing a laptop to a calculator......but I feel an upgrade is only warranted if you have upgraded your engine beyond factory specs.

 

Isn't that what they use to do in F1 Racing? They would have dump unburned fuel into the burning hot turbine to make it spool quicker. I read this somewhere I believe. Anyone know what I'm talking about? I think they termed it the "5th Stroke".

 

I think you might be referring to Rally Cars etc.

I believe they have a button on the dash which is pressed prior to launching the car off the line. This has the effect of allowing burning fuel to pass down through the exhaust manifold to the turbos thus keeping the tubine spinning at good rate. You can hear it. Its to pop, pop, pop sound you here whilst they hold RPM on the line.

 

are you sure its a spark controller and not just a ignition amp?

as for aftermarket boost controllers,, im sure the hardware inside the ecu can handle any mods you chuck at it if set-up right, there is more fuctions insode the ecu which can be unlocked which alot (nearly all) tuners dont know how to gain access too,, one which i know about is altering the number of load sites (making the load/rpm feul sites larger)

If you really wanna go down this road it would be worth ripping the whole ecu setup out and fitting something like a PECTEL GEMS or MOTEC ecu!

great topic btw

 

the system you are on about is ALS (anti-lag-stratagy) in the early days of this working it would just dump fuel into the exhaust housings, but later on different systems have been tried,, like when changing gear, an air bypass will open around the throttle plate, at the same time the ignition timing is retarded around 40 degrees, fuel is placed in as normal, because the ignition is so far retarded the exhaust valve is starting to open and the expanding fuel/air mix rushes out the exhaust and into the exhaust housing of the turbo, giving the turbine energy to spin (and yes, massive flames and loud pops and bangs)

systems have even moved on further from my last statment,, this system is called EGR ALS (dont worry EGR has nothing to do with the system fitted to modern cars to control exhaust gases)
what EGR ALS does, is link the outlet of the compressor housing to the inlet of the exhaust housing, this turbos our turbos into turbines (like a plane) this is what modern WRC rally cars have fitted and with in conjection with normal als

 

I also hear that this causes lots of wear on the turbine. I guess it wouldn't be a good idea to do on a street car.

 

you cant really do it with a standard turbo, you really need a maram shafted turbo with a inconnel exhaust wheel, I'll try and upload a video of my road car with it on,, sadly nothing as nice as a f40 though

 

well seeing as how i own a moderatly modified twin turbo engine, i will say a few things.. get a boost controller. and an air flow controller.. they are not stand alone.. the car will still detect knocking/overboost blah blah.. the boost controller will be solonoid activated to open and close the wastegate.. you know how your waste gate is messing up? well this will be able to controll it with its own little brain.. very very efficient. and the air flow controller will help even more..i highly recomend them as they fine tune the turbo system to help preserve your engine and get the best performance out of it. i only recomend raising boost on an upgrade ecu though.. not too sure of the specs of the ecu/injectors of an f40.. also, blow off valves will offer you no additional performance.. the only thing a new blow off valve will do for you is hold more boost.. some bovs leak under high boost creating a boost leak..messing with the wastegate can be bad news unless you know what your doing.. you might be leaking your exhaust past your turbine right now because of those adjustments.. i would definatly look into the greddy e-01 boost controller and the apexi safc version II.. or you can use the greddy emanage with the e-01 but the apexi safc has more functions and works better imo.. good luck

 

sorry i really think this is bad advice,,the f40 boost control system is closed loop system,, meaning it looks after itself to a degree, the problem with adding a boost controller is that it is taking away the control in this loop! We all know it will still see the boost but what can it do about it once the boost controller is added? nothing!

You really gotta look at cars like world rally cars,, these are turbos and do they use a seperate controller,, NO,,, the reason behind this is simple ,,,control

this is nothing wrong with the processor speed of the ecu to control boost, the boost control valves can fail,, but there is a fix for this aswell, but i have never seen them on a f40! they would be AIR-TO_AIR boost control,, this is a bleed on system where the standard system is a bleed off! it would require a simple mod to the ecu control and alsot he fitting of air injectors

Gareth

 

ok so no boost controller............but how would one stop the wastegate from prematurely opening and causing loss of power.....the computer is not controlling the boost adequately.....will a ECU with upgraded software solve the problem???
or replacing the wastegate with a harden race version......maybe a new spring in the wastegate?????......but if you replace your turbos to LM spec or bigger ones....can the factory wastegate be adequate????............how many licks to the center of a tootsie pop....jk

 

new srpings wont be a bad move,, plus i guess they are cheap and easy job

as for specing the car with different turbos and wastegate sizes i cant really help as ive never had nothing to do with the f40!

 

like i said, along with the greddy emanage, the greddy e-01 will put the car into safteyboost.. the emanage controls air/fuel, ignition, blah blah.. obviously the f40 has issues coping with mods related to exhaust.. so maybe if there was a device to better control the turbos under this difference in exhaust flow, he should use it.. messing with waste gates may fix one problem, but its not the solution first of all.. second of all it will cause another problem.. get a boost controller and a air flow controller that can talk to your ecu about knock..it will then talk to the bc and tell it to go into saftey boost.

 

the problem with increased airslow isnt the ecus fault its just bad mapping of the ecu!