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General Car Related Discussion.To discuss anything that is related to cars and automotive technology that doesnt naturally fit into another forum catagory.
I'd be interested to hear marks take on the comparison of tuning ybs and Evo engines as he's tuned both multiple times, everyone who I knew who had cossies around the millennium all had head gasket trouble including me
I'm guessing the Evos are a better design from the start, they certainly seem to spool those 9180s easier for some reason
IMO I’m gonna say not that different, a pretty similar engine as standard then by the time they are modded for big power they both have better cranks, pistons, gaskets etc etc.
With regards to headgaskets being a weak link on the yb I guess it just depends on what arrangement you are using to clamp it
Cheers Paul
that’s the thing I’m guessing the long studs head gasket and process mark uses are pretty similar on both engines
I’m sure mark said a yb generally makes 30hp more than a similar spec 4g63. I wonder if anyone has headgasket issues with a steel gasket and correct design longstuds. Of course both engines have their flaws though.
Im sure mark said a yb generally makes 30hp more than a similar spec 4g63. I wonder if anyone has headgasket issues with a steel gasket and correct design longstuds. Of course both engines have their flaws though.
My opinion of it Is this, once past say 300 hp per litre of capacity the forces within that cylinder are huge, and failures are going to happen, there is no way can any engine be built to run that level of power and be reliable for tens of thousands of miles, certainly not under hard use anyway imo
Remember a Bugatti veyron is an 8.0 liter, so even at 1500 hp it's still only 187 hp per litre, the 801 hp Evo for instance is 364 hp per litre, my yb is currently 330 hp per litre, it's alot of power to be making out of a new modern engine let alone one designed over 30 years ago
To put it in perspective the rate of tune it's like an equivelant rs6 running 1320 hp or a gtr at 1254 hp which is huge power even with today's engines on pump fuel
And the equivelant tune Bugatti veyron would be 2640 hp !
I'd be interested to hear marks take on the comparison of tuning ybs and Evo engines as he's tuned both multiple times, everyone who I knew who had cossies around the millennium all had head gasket trouble including me
I'm guessing the Evos are a better design from the start, they certainly seem to spool those 9180s easier for some reason
The previous Evos I have done before Simons Evo tended to make 30hp less than a YB but his one just went and made more power easier than all the other cars before it. So it will be interesting to ramp up the YB to see where it goes too.
the Evo long stroke small bore definitely helps spool and adds low end power over the short stroke large bore YB and the head gasket lasts longer but still can start having problems past 700hp with deck face distortion which I sorted on the big power Evos with a steel coated liner helped that. Simons engine never had a problem in its life which was over 15k mile which is very good going until it had a injectors problem.
Am I right in saying that evo had a taller block fitted to give a mega long stroke? Also do YB’s have gasket problems once fitted with correct long studs and steel gasket mark?
The previous Evos I have done before Simons Evo tended to make 30hp less than a YB but his one just went and made more power easier than all the other cars before it. So it will be interesting to ramp up the YB to see where it goes too.
the Evo long stroke small bore definitely helps spool and adds low end power over the short stroke large bore YB and the head gasket lasts longer but still can start having problems past 700hp with deck face distortion which I sorted on the big power Evos with a steel coated liner helped that. Simons engine never had a problem in its life which was over 15k mile which is very good going until it had a injectors problem.
Mark
We better see how far the old yb can be pushed then boss see how she fairs against the Evo on pump fuel with the big housing on
Have you got a dyno plot of the Evo on pump fuel pal ?
I thought there had to be something, Evo smaller bore so I presume more area of head gasket around the bore ?
Last edited by scoooby slayer; 06-02-2020 at 03:31 PM.
We better see how far the old yb can be pushed then boss see how she fairs against the Evo on pump fuel with the big housing on
Have you got a dyno plot of the Evo on pump fuel pal ?
I thought there had to be something, Evo smaller bore so I presume more area of head gasket around the bore ?
tbh looking at a 4g63 block there looks like less surface area between each bore
Am I right in saying that evo had a taller block fitted to give a mega long stroke? Also do YBs have gasket problems once fitted with correct long studs and steel gasket mark?
That one had a taller block which I used a 7.5mm longer rod and a 9mm longer stroke to make a 2.227cc engine it also had a 86.5mm bore but I linered it back to a 85.5mm bore due to the space between the bores being so small on that block.
That was a good watch mate, I mentioned the other day this torque in lower rpm causing higher cylinder pressures than higher rpm but I wasn't sure, that video confirmed it torque in lower rpms causing more pressure at lower rpm as it's producing the torque with the pressure in the cylinder longer due to slower rpm
Absolutely, but they're deliberately doing it because the restrictor ultimately limits power and rpm. So they need to go fast with torque where possible
The YB is so old that it was simply never designed to do what we do with it. I have to cap boost spikes in the low rpms to keep the head on it. At 3.2 absolute at 2400rpms my YB lifted the head and coolant pressure increased rapidly. I have capped it to full boost from 3000rpm, but with the 34mm intake by 5500rpm torque has dropped off dramatically.
Bit more info I've found for my car
9180 on 1.45 housing while mad road mapping has seen 10 psi at 3700 rpm giving an idea of on road boost in higher gears
And it does all make perfect sense and shows how less can mean more, easy making power with the motor in that video though same with the gtr and RS6
25-30 hp per pound of boost, the joy of displacement mate
Alot harder with a little yb
I've done an overlay of rods previous spec gt42 engine at 2.8 bar on race fuel, and then my last run at 2.2 bar with the efr9180
Now I know I'm 100 hp and 80 lbft behind atm but another 0.6 bar of boost should cure that and still be on pump fuel
But look at the gains in the lower end, over 500 rpm gain in spool, and if I had a run of rods back then on 2.2 bar pump fuel I'm sure the peak figures would be lower to, which proves the efr9180 is flowing like a gt42 but with far better response
Last edited by scoooby slayer; 12-02-2020 at 07:06 PM.
Sorry if youve already said but whats the most bhp rod ever ran with this car in its life?
To the best of my knowledge the 809 hp 629 ft-lb was the most it ever ran on motorworx dyno, gt42 turbo, 2.8 bar of boost race fuel
I'm hopeing to get around that on pump fuel
I think it has run 850 hp including nos in the past and that was I believe when it did 206.1 mph
In theory it should do over 900 hp now but I'm not going that far it's to much for it imo
I went out in it with out nos used with over 700bhp me and Neil was doing something while Rod was messing about with the car and he took us out in it after to test it. He drove it in real anger up past the hatch pub in Basingstoke up towards Hook then turned off towards odiham to turn round at the roundabout and head back. Still to this day the fastest thing I’ve ever been in it was shocking how fast it was.
I went out in it with out nos used with over 700bhp me and Neil was doing something while Rod was messing about with the car and he took us out in it after to test it. He drove it in real anger up past the hatch pub in Basingstoke up towards Hook then turned off towards odiham to turn round at the roundabout and head back. Still to this day the fastest thing Ive ever been in it was shocking how fast it was.
Do you remember what turbo was on it then ? I'd imagine the gt4094r
I can't stop at 710 hp, as Paul rightly pointed out it's a mispecced turbo for that power and I might aswell go down a size, and I don't want to change rods spec unless I absolutely have to so the only solution is 800hp then it will be spot on
V power pump fuel, 2.7 bar 39 psi of boost, efr 9180 1.45 ar housing standard valves 2150cc yb
768 hp, 600 lbft with another approximately 60 hp left to go if race fuel is used
It may feel different on the road, but I'd definitely want something that spooled a lot earlier than that
I won't know for sure til I drive it but judging by the dyno plot I will be happy, 2500 rpm of over 600 hp is the same as my supra was and I loved that
And coming onto boost is abit more gradual rather than a vertical line so should help with keeping traction
If I wanted excellent response then I'd change the turbo to something alot smaller and alot less power
The flow of a gt42 with better response I'm happy
Supra is a 3.0 though with a lot more power/torque off boost and ramping up
A friend's 4cyl car made similar numbers back around 2011 on a dyno, probably peaked a little earlier...But in reality it was horrific to drive, and on track needed to be taken to 9k to be usable. Which in itself caused other issues
You said it had been tried before with the smaller turbine housing that spooled a lot earlier, but sacrificed only a very small amount up top ? How come you didnt go down that route ? Or is it still an option ?
Supra is a 3.0 though with a lot more power/torque off boost and ramping up
A friend's 4cyl car made similar numbers back around 2011 on a dyno, probably peaked a little earlier...But in reality it was horrific to drive, and on track needed to be taken to 9k to be usable. Which in itself caused other issues
You said it had been tried before with the smaller turbine housing that spooled a lot earlier, but sacrificed only a very small amount up top ? How come you didnt go down that route ? Or is it still an option ?
Shoot 44 is not a high ramp rate on the dyno, marks testing on the road shows some boost earlier than the dyno suggests
I can't remember now I think the smaller housing is 500 rpm sooner or there abouts, it can be altered for a smaller housing but I want to keep it as is
0.7 bar of boost under 4000 rpm on the road
Last edited by scoooby slayer; 05-07-2020 at 12:18 PM.
I'm not sure on full boost but 23 psi is 5400 rpm at a low ramp rate on shootout mode
Not sure on power drop either must be just past it's sweet spot, but still making over 700 hp right to the limiter, should be a screamer ripe for thrashing to 8500 rpm 😁😁
It will still be the most awesome Saff in the UK!!!!!
Cheers mate I'm certainly very happy I've got to own it and with the outcome of the tuning
Nigh on 800 hp with a 2 litre on pump fuel is never going to be a super responsive engine
But to me the curve looks good, above 300 hp at 5000 rpm, above 400 hp at 5500 rpm, above 600 hp at 6000 rpm then 6500 - 8500 rpm over 700 hp, she's certainly gonna peddle along I have no doubt 👍
I would hazard a guess in a best case scenario that any turbo making this sort of power on a yb isn't going to hit 23 psi much below 5000 rpm on a DD dyno in shootout, on an engine dyno it will make it much sooner but it's not real world load so not comparable
I've just looked at another datalog and 4200 rpm there's 7 psi, doesn't sound alot but it will be enough to wake it up as she's upto 200 hp even at that low of a boost
Last edited by scoooby slayer; 06-07-2020 at 12:47 PM.
I've just found this data log from the old 2.2 bar tune out on the road
If we look at turbo speed 100000 rpm on full shift, mark then shifts gear turbo speed retains 65000 rpm at lowest point then straight back upto 100000 rpm again
I'd never looked at this in depth before til now, but that suggests after shifting there's enough boost threshold to grab the next gear and be quickly back into full beans again
06-02-2020, 09:10 AM
see how she fairs against the Evo on pump fuel with the big housing on
