Meth drinkin turbo crossy

[Butcha 111]

First start of the day after changing pumps. Starts pretty good for a meth engine.

[ando76 4,354]

Shame you couldn't make it bud - we had a really good night - until Brenton got fenced.  Never mind

[Butcha 111]

ol mate was doing alright didnt quite catch what caused him to fence but he went in hard. Was good just to watch tho. Dusty as hell do the mods get decent traction with the track like that? we don't.

[ando76 4,354]

Nah mate traction suffers - especially if you have good hp.  Lucky the carton motor didn't suffer from that so what it had, it got to the ground.

 

Brenton copped a good tap on the right rear corner after he passed Dave Stretton - who was driving Max's car (5).  Dave was loose and rusty as and turned into Brenton.  Nothing intentional I don't think - just a case of old rusty driver in a car with plenty of stick. 

[Butcha 111]

Fyi The rigs still goin last meet i fucked up with some ecu parameters and after 2 laps engine went off song and was huffing oil out the dipstick...fuck. got home and i found i blew the head gasket on 2,3,5,6 and blew a hole from the chamer on number 6 though to the pushrod hole. Coating the pushrod in molten alluminium.

 

Assembled the spare head i had here with the valvetrain and shes back up and running for tomorrow night. Had bit of a play today with the tuning and it feels good. Ripped 100m skid in 3rd on the road @7000rpm and she feels good so we will see how we go tommora night.

 

I will say the turbo feels lazy as i am down from 12:1 compression down to about 10:1. Though it should give me a wider tuning window.

[Butcha 111]

Anyone want to guess rwhp this thing made @8psi and again at 15psi?

[gerg 10,871]

I'm guessing 280?

[ando76 4,354]

Depends whose dyno you used. 

 

Should be stout HP and mountain of torque

[Butcha 111]

ill do a little write up and put dyno sheets up lil later but in short,

 

Went there and played with fuel a bit then did a power run and did 290rwhp @25 deg timing.

 

Added a bit of fuel but it dropped a few horses.

 

Bumped up timing to 30deg and it made 310rwhp

 

Bumped up timing to 35 and it made 321rwhp.

 

I think the fuel is way rich as my 02 was bottomed out but the dynos was reading about 5.0 -4.8 so i didnt know what to believe.

 

So i cranked in the dial on the wastegate and it went 401.7rwhp and climbing but the bloke stopped about 5400 as the alternator flipped its belt an threw a shitload of smoke.

[Butcha 111]

Around 2250 lb tractive effort whatever that means

[wagoon 2,429]

Around 2250 lb tractive effort whatever that means

BIG balls

[Butcha 111]

 

Ok as promised.

 

Run 1 was as i had it @24 deg timing 8psi base it wasnt happy as i think it was way rich and was bucking a bit in the top. I played around a little with fuel and did a few other runs which were within 5hp of this.

 

Second run at 30deg timing straight after the above and pulled around 311 much cleaner up top. changed the timing to 35deg and did another run straight up and netted the 321 you see there.

 

Had a fuel leak and mucked around a bit fix it. I thought it was way too rich the way it was falling off up top.my gauge was going off the scale (below 4:1). Yet his probe was saying about 5 to 4.8 which was too lean for my liking.i figured the quickes way to see was to add more air rather than pull fuel. With the timing pulled back to 30. Cranked in the wastegate a turn..

 

The 394hp run was pulled early as the hp shot out of range of his screen, he changed it his screen and did another pull but pulled it up short (i told him to go to 6500) as a shitload of smoke came out the bonnet. The alternator belt rolled over and shit itself. So 401.7hp back to back run. the tractive effort is much flatter so i guess it needs less fuel up top. No spare alterator belt meant the end of a session.

 

I need to go back through the dataloggs to see what else is happening with intake temps etc. But im reasonbly happy with that last figure for what it is. It hits the rollers hard when it comes on boost. Took a few goes in strapping car down and mucking with tyre pessures to hold er down.

[Butcha 111]

Dunno if the torque curve is supposta be like that, looks different to any other dyno graph ive seen

[gerg 10,871]

You can convert that tractive effort back if you know tyre diameter, diff ratio, what gear it was in and the ratio of that gear.

[gerg 10,871]

That tractive effort is a simple linear conversion to torque. Looks like the turbo spools up and torque comes on hard but then dips for whatever reason, possibly you have wastegate issues or blowoff leaking?

 

That's still plenty of herbs right there

[Butcha 111]

Was in 4th 1:1 5.83 diff & 87" diameter tire.

Yeh im not sure whether it was the car coming up on the rollers and dropping back down a bit or car issue?

[gerg 10,871]

Ok do you actually mean cm instead of inches or are you talking 87" circumference? 87" is a tractor tyre.

[Butcha 111]

28" sorry 275 60 15

[gerg 10,871]

Lol that's better

 

So half of that gives you a radius of 14" then to make it into feet that's 14/12

= 1.167'

 

2250/1.167 = 1928 lb-ft at the axle

 

Then divide that by the diff ratio 5.83 (wow serious?)

 

1928/5.83 = 330 lb-ft at the flywheel given a 1:1 gearbox ratio

 

This is with drivetrain losses and tyre friction/slip which are anyone's guess

[gerg 10,871]

Sorry fucked that up it should be 2250 x 1.167 (not divided)

 

So in the end it should work out to be 450.39 lb-ft at the fly... That sounds more like it.

 

That's close to 600 Nm, and that's taking out the drivetrain losses.... What a beast!

[Butcha 111]

that good? feels good.

[ando76 4,354]

Nice result Butcha.  Yeah the torque line is supposed to look like that - torque falls off and HP increases. 

 

Notice the torque line on the runs that made the most power.  See the difference to the ones that made less. 

 

As you increase and hold torque for longer - you make more power.  How do you increase torque - you play with timing to make sure that the engine is getting what it needs - timing wise at each rpm point. 

 

solid results mate.  Meth turbo and 35 degrees of timing - gotta love that

[Butcha 111]

Kinda want a dyno for me own now could play on the thing all day wanted to do that last run with 2 degrees more timing, pull some more fuel, more boost..

[Butcha 111]

Just going through some datalogs an am trying to make sense on what is happening. In the first one you can see the boost shoulders off at 8.5psi then creeps to 12. Making no changes bar 1 turn on the wastegate screw and the thing rockets off to 20psi but still shoulders around 8.9 psi...any ideas or theory on whats going on?

 

 

[gerg 10,871]

Boost building slowly after wastegate opening normally means it's too small to dump the exhaust flow to the turbine. But that doesn't explain the other run where the opposite seems to happen.

 

XPTCrossy knows turbos so maybe he'll use his skull and chime in with some ideas