What Engine for 500BHP

[andygtt]

turbonutter said:

andygtt said:

What is the power curve like on a stock engine thats not turbocharged?

Despite the lower CR Id expect your power curve to be better than the NA everywhere and just have it increase when boost comes on.... if the stock engine doesn't have much power low down its going to be hard to change that dynamic pre turbo spool.

I will have to look for one, as I cant find it at present....

It was kind a leading question, as I plotted your power curve on my spreadsheet that I have for mine to do a comparison.

Its a good comparison as basic specs for our engines stock and modified are very similar. both V6, 3.0L and 3.2L, relatively mild cams, similar size single turbo, rods and low cr pistons etc... stock engines in NA form make similar power (your V6 is 15-20bhp more in NA tune).
I run more boost and rev a lot higher than you with a peak power 1000rpm higher... so based on all this you would expect yours to make more down low, but in fact your you are running less power down low and you spool up later as well.

As another comparison, my engine spools up later and has less power down low than the twin turbo versions of similar spec.... I was expecting yours to trounce mine down low... I think something is holding your entire engine back as you seem to be down everywhere, and if its down on power down low then that will effect spool etc etc.

[turbonutter]

So Here is a stock GTA Power Curve.



and here a comparison.
Curves from:
AET Hub Dyno (wheel power) when running 1.3 bar
John Sleath's rolling road (Flywheel Figures) running 1.0 bar
& the stock figures.



Not perfect comparisons as the AET plots start at lower rpm & the figures at 1 bar on the RR, had briefly helt the rpm at 3000 before the pull..

Unfortunately I just had a call from work & there are some issues on my ship, so I have to go back in a coupl eof days, a few feeks earlier than planned, so there wont be any chance to do any testing

[andygtt]

Ok you don't look horrific compared to the standard NA engine.

Maybe its worth mentioning that the standard noble 3.0L engine had completely standard cams with just shorter rods to lower the CR... however the cam timing on the exhaust cams was set back a single tooth.. forgetting the technical arguments about this what it actually did on all the cars was drop the power band back 500rpm giving more low down power but it tailed off similar place to yours.
Maybe this is an avenue for you to research while on the vessel?

As I say the Ford V6 is very similar to yours and Noble turbocharged it so you might be able to use this engine as a loose baseline to compare especially cam timing?

[turbonutter]

andygtt said:

Ok you don't look horrific compared to the standard NA engine.

Maybe its worth mentioning that the standard noble 3.0L engine had completely standard cams with just shorter rods to lower the CR... however the cam timing on the exhaust cams was set back a single tooth.. forgetting the technical arguments about this what it actually did on all the cars was drop the power band back 500rpm giving more low down power but it tailed off similar place to yours.
Maybe this is an avenue for you to research while on the vessel?

As I say the Ford V6 is very similar to yours and Noble turbocharged it so you might be able to use this engine as a loose baseline to compare especially cam timing?

Definately worth comparing the Noble engine specs with my engine, I have planty of time, so will try to investigate as many options as I can...

[turbonutter]

So just a quick question while we are taliking turbo's.

What would be a maximum temperature at the turbine inlet. I think I read somewhere that 950C was about as hot as you would want to go?

[anonymous-user]

Std turbines will take 975degC continuously (we'll ignore the thorny issue of how you can't actually measure exhaust gas temp or the temp of the turbine material directly)

Motorsport turbines, with special materials will run up to 1050 degC continuously and 1100deg intermitent

[turbonutter]

Thanks thats what I thought. I assume the actual turbine wheel temperature is hotter than measured by the EGT probe, so 950C would be a reasonable max limit to use. What little logging I have of the EGT's I am pretty close & that was with 15C ambient temperatures, So I may have to look at Water Injection - Will see how the temperatures look when we get some warm weather

Edited by turbonutter on Thursday 19th November 16:31

[andygtt]

I measure mine around 3inches from the head (one on each bank) and see EGT of 950deg c on full boost... around 900deg c on low boost (around 500whp).

Its quite a dynamic sensor in that on track I will see it increase on straight and drop in braking and corners so its not 'all' heat soak into the sensor... so far my turbo has surprised.

Strangely to me (probably not to the experts) I found the EGT doesn't get anywhere near my full throttle EGT's when I am using the anti lag/ launch control... given the amount of claims that this kills turbos due to heat I was a little surprised.

Nothing like actually recording your own data and analysing it.

[anonymous-user]

Except what you are measuring is the temperature of the tip of your temperature sensing probe, and not either of: 1) exhaust gas temp or 2) Turbine / exhaust line component temp.........



Of course, unless you are developing new parts, or pushing the absolute limit, then "rules of thumb" come into play. By which i mean:

"if you measure 950degC with a 3mm thermocouple just upstream of your turbine, chances are the actual turbine temperature is acceptable" etc

In reality, we use tribological and materials science methods to assess peak exhaust line component temps, and then reference these back to measured temperatures encountered during the thermal survey process.

In all cases, the actual gas temp is WAY higher than you actually measure!

[andygtt]

Ive not broke the turbo yet so Im guessing its in acceptable range :big laugh:

If the sensor is reading much lower when running launch, then is it logical that the turbo is seeing lower temps as well?

[turbonutter]

Finally after being home 2 months, I managed to find time to get the car to the MOT station & back on the road.

Did a quicl logging session for temperatures & have found with an ambient temp of 10-12C, I am getting 38C inlet air temp & 950C EGT before the turbo, obviously this will increase when summer finally comes along, so I am looking at fitting some water injection.

I was thinking of using a Devils Own Progressive Kit: http://www.methanol-injection.co.uk/index.php?rout...

Anyone got any thoughts on which Water injection kit to use???

[stevieturbo]

turbonutter said:

Finally after being home 2 months, I managed to find time to get the car to the MOT station & back on the road.

Did a quicl logging session for temperatures & have found with an ambient temp of 10-12C, I am getting 38C inlet air temp & 950C EGT before the turbo, obviously this will increase when summer finally comes along, so I am looking at fitting some water injection.

I was thinking of using a Devils Own Progressive Kit: http://www.methanol-injection.co.uk/index.php?rout...

Anyone got any thoughts on which Water injection kit to use???

Under what conditions are you seeing 950deg ? I always wonder about the accuracy of those thermocouples, with no actual easy way to test them. On a recent 1/4 mile run from my own car, EGT's pre-turbine rise to a little over 900degC. They're still climbing, but quite slowly at that point.

TBH, for a complete package, Aquamist probably offer the best stuff, they use better controllers and have failsafes built in ( either via the ecu or simply killing the boost solenoid which should reduce boost )
Aquamist seems more expensive but it's because what they're offering is a better system for that price.

If you opt for more basic stuff, prices arent so different to the US based stuff.

http://www.aquamist-direct.com/aquamist-systems/

Alcohol Injection Systems in the US make the nicest tanks, as they make them where you can conceal the pump within. I think Devil's own do some similar tanks in the US too, but not as nice. Really depends what sort of shape/size tank you really want.

http://www.alcoholinjectionsystems.com/index.php?c...

Whilst nylon lines do work...if you can teflon/AN lines and fittings will ultimately be more reliable. Although again, most of the US stuff tends to use pneumatic style push fit fittings, Aquamists are slightly different many being actual compression fittings.

AN fittings and teflon are cost extras.

But the Devils own stuff is fine too, I use their nozzles and holders at present, although an AEM pump and Snow Performance controller that I've had for 12 years or so.

Most of the companies all use the same Aquatec pump anyway, their progressive controllers are all pretty much the same too. Again the exception being Aquamist which takes in more info and regulates meth flow relative to injector duty cycle as opposed to just using boost. They also prefer running the pump flat out and regulating flow via a solenoid. IMO a much better setup, more akin to the regular fuel system and will be more efficient in terms of how much fluid it uses.


Of course on the other hand, your ecu should be fairly comprehensive, it should be able to control their FAV, it should be able to turn the pump off/on. So really your ecu should be able to become the controller meaning you need to buy fewer parts.
via a SSR you could PWM the pump itself the same as the progressive controllers do if you wanted to go down that route instead.

[turbonutter]

I saw the 950C a number of times accelerating 2nd,3rd,4th,5th...


I had a thermocouple at work, with an amplifier and used our dryblock temperature calibrator to see hoe they worked and upto 500C (max for out calibrator) the reading on the calibrator agreed with the amplifier output +/- 5C, so I would guess they are reasonably accurate..

Of course Aquamist, I was thinking the company was cooling mist..... Definately the system they have looks better, as it has the failsafes & monitors the flow, so will detect clogged nozzles etc...Its probably worth the extra for this function.

[stevieturbo]

AEM sell a flow meter with a 0-5v output.

This could be used to feed into an ecu for either safety purposes or an actual load parameter to make fuel/timing adjustments.
Only caveat with a flow meter is a burst pipe would see flow, but not into the engine. ( rare scenario though )

If it monitored flow and pressure, which I think Aquamist does....it's fairly well covered.

Although if the ecu has good closed loop fuel adjustments and knock control, hopefully this too could catch any problems, or lean trips etc

Depends how much water/meth you want to use. If only small amounts to keep things a little cooler rather than pushing hard for more power, you could easily forego external safeties and maybe just spray a little water based on charge temps, EGT or whatever
ECU control would be by far easiest way for that if you had a couple of spare outputs. ie one for the pump and one for the control solenoid. Unless you choose to PWM the pump itself in which case only a single ecu output would be needed and a SSR or similar to carry the load.

[turbonutter]

stevieturbo said:

AEM sell a flow meter with a 0-5v output.

This could be used to feed into an ecu for either safety purposes or an actual load parameter to make fuel/timing adjustments.
Only caveat with a flow meter is a burst pipe would see flow, but not into the engine. ( rare scenario though )

If it monitored flow and pressure, which I think Aquamist does....it's fairly well covered.

Although if the ecu has good closed loop fuel adjustments and knock control, hopefully this too could catch any problems, or lean trips etc

Depends how much water/meth you want to use. If only small amounts to keep things a little cooler rather than pushing hard for more power, you could easily forego external safeties and maybe just spray a little water based on charge temps, EGT or whatever
ECU control would be by far easiest way for that if you had a couple of spare outputs. ie one for the pump and one for the control solenoid. Unless you choose to PWM the pump itself in which case only a single ecu output would be needed and a SSR or similar to carry the load.

I think the aquamist also monitors for excessive flow, i.e. burst pipe.....

At the moment I am just looking to cool things a little, but I guess ultimately I will want to add a few BHP as well, to get back to where i was before it blew up

You are right, I could quite easily use the ecu to do what the controller does, with a pwm table with boost or injector duty 'vs' air temp & with another to trigger the pump on. Safety wise I have knock control & can also take a chunk out of the boost solenoid base duty if the temp goes high, so that should cover it.

If I do it that way, then I could use a Devils own pump, with -4 Hose & their race tank, which is quite nice & just use a Aquamist Fast Acting valve for the control.... or skip the fast valve and pwm the pump via a SSR, depends what outputs I have available (i am sure I have plenty of spare ones)...

[stevieturbo]

Yep, all are options.

External controller like aquamist can simplify things to a degree, as it's one package, just install it, all easy.

But there's a lot to be said for ecu control if it can do it too and it will be cheaper for the actual install.

Obviously there will be tuning time, but that's going to apply anyway

[turbonutter]

stevieturbo said:

Yep, all are options.

External controller like aquamist can simplify things to a degree, as it's one package, just install it, all easy.

But there's a lot to be said for ecu control if it can do it too and it will be cheaper for the actual install.

Obviously there will be tuning time, but that's going to apply anyway

The simplicity of the install for the Aquamist system is not as simple as it first seems... Yes its all one package, but I would need to find somewhare for the Dash Gauge and the controller - not difficult, but the dash is already full...

I have checked the ECU and I have 2 spare PWM outputs that I can use, so I just need to decide if I should control the pump or use an aquamist FAV.

You mention a need for tuning...
If I just spray some Water/Meth, what effect would that have. I realise to get more power, a new tune would be required, but does the Water/Meth affect the AFR's?

What do you use Water or 50/50 water/Meth?

[227bhp]

Why are you seeing overly high EGTs and is it not better trying to bring them down by tackling the cause rather than band aiding it?

[stevieturbo]

Depends whether they're overly high...or normal ? pre-turbine temps will always be hot....and fuel used will play a huge role in that.


Whether you use water or meth...or mix really depends.

Water will cool best...but you're putting water into the engine which cant really help power as such. So if using water, use sparingly
The more you side towards methanol, the less critical it is as to how much you inject and why it's so popular with the yanks etc. It's almost idiot proof...just dump tons of meth in. It will help cooling and add octane too.

But for just cooling, chamber cooling and not getting aggressive with the tuning after, 50/50 is probably a good place to be, and again dont inject huge amounts.

For last while I've just 1000cc jet ( 2 smaller jets = 1000cc or thereabouts ) and the bigger AEM pump. Even that isnt as much as some guys dump in but I dont really think I need or want anymore. I'm using 100% meth, for the only reason I get fed up mixing the stuff as ended up with drums mixed at different amounts and could never remember what was what, but I dont use huge amounts anyway as it's only a handful of times when racing I can use any extra power.

[stevieturbo]

What sort of mixtures and timing is it running at those temps ?

Looking at my logs from the other weekend, runs seem to vary from around 910-944degC at the end of a 1/4 run.

No real rhyme or reason as to the differences. Mines definitely a little rich, but also very safe on the timing, some air temps were getting up to 60degC but that's only as there was a load of heat soak from sitting about prior to running.

That's without methanol injection, didnt bother any runs using it.