GT3071 Turbo @ 2.4bar on a YB engine gives 514BHP!
20-10-2010, 03:43 PM
#89
Its very rev specific.
IMHO (other engine tuners will vary in their opinion Im sure but still follow a similar pattern in terms of it increasing with rpm)
At 4000-5000rpm, the ideal compression ratio on 98 RON fuel is probably around 8:1
at 5000-6000rpm its probably more like 8.5:1
at 6000-7000rpm its probably more like 9:1
and at over 7000rpm is probably over 9:1
20-10-2010, 06:44 PM
#92
PassionFord Post Whore!!
Martin thats not in shoot 44 mode so the ramp rate will be diff it would be good to see this power run done in S44,
Heres Dougs before and after boost and TQ and Boost and HP
Theres internal gate turbos work well but dont quite have the boost control of the exturnal.
Mark
20-10-2010, 06:46 PM
#93
PassionFord Post Whore!!
This has been mapped to 1.5bar boost under 70% TPS and under 5k so its easy to drive without over loading the tyres when cornering.
Mark
20-10-2010, 06:48 PM
#94
PassionFord Post Whore!!
.Mark
20-10-2010, 06:51 PM
#95
PassionFord Post Whore!!
It wasnt the exhaust housing on a .82 causing the lag it was the cams,
I would never use a .63 a GT30 as it just kills the turbo and you have to limit the boost being in fear of a meltdown on a long run.
Mark
20-10-2010, 06:53 PM
#96
PassionFord Post Whore!!
well done mate
20-10-2010, 09:05 PM
#98
Mark, it was in shoot44, cause i asked martin that by PM, he just took a screenshot on his phone rather than did a printout cause it was quicker to pull it up like that so thats why it looks different.
And I said the same thing about the cams causing the lag, I just said that doug didnt want an .82 cause then it would be even worse, I wasnt saying that a .82 would be solely responsble for lag, IME the .82 works well on a gt35 in fact.
And I said the same thing about the cams causing the lag, I just said that doug didnt want an .82 cause then it would be even worse, I wasnt saying that a .82 would be solely responsble for lag, IME the .82 works well on a gt35 in fact.
20-10-2010, 09:33 PM
#102
Too many posts.. I need a life!!
21-10-2010, 07:26 AM
#104
I simply went in and searched out one of Jasons files, to get all the data at the bottom of the graph you actually have to put the dyno into shoot out mode. Run 036 actually comes on power sooner, the graph I posted was the first one I looked at. 
Last edited by Martin-Hadland; 21-10-2010 at 07:56 AM. Reason: re-scaled graphs
21-10-2010, 12:13 PM
#106
10K+ Poster!!
Very impressive power that. I bet the car flies!
24-10-2010, 09:40 PM
#107
Took it out for a drive today.
To answer rentons question from earlier, the torque spike that looks mental on the graph doesnt unsettle the car at all on the road.
In second gear the revs rise so quickly on the short 3.9 gearing that the boost follows a slightly different curve anyway and feels very smooth.
3rd onwards its got so much natural grip that when the power does come in, which starts building at 3500rpm it just accelerates hard and doesn't feel like it's pushing the grip limits.
Really nice conversion, wether you change gear at 5k or 7k its straight back on the power in the next gear either way and pulls hard regardless.
Doug is over the moon with it, he wasn't a fan of revving the old engine as hard as you had to in order to make quick progress and now it's faster at 1000rpm less.
To answer rentons question from earlier, the torque spike that looks mental on the graph doesnt unsettle the car at all on the road.
In second gear the revs rise so quickly on the short 3.9 gearing that the boost follows a slightly different curve anyway and feels very smooth.
3rd onwards its got so much natural grip that when the power does come in, which starts building at 3500rpm it just accelerates hard and doesn't feel like it's pushing the grip limits.
Really nice conversion, wether you change gear at 5k or 7k its straight back on the power in the next gear either way and pulls hard regardless.
Doug is over the moon with it, he wasn't a fan of revving the old engine as hard as you had to in order to make quick progress and now it's faster at 1000rpm less.
25-10-2010, 10:29 AM
#111
Advanced PassionFord User
iTrader: (4)
Join Date: Sep 2008
Location: Sutton
Posts: 2,250
Likes: 0
Received 0 Likes
on
0 Posts
Believe so, last time Mark had it in it had a huge boost leak have sorted that now so all l need is inlet cam more boost and of we go!!!!!!
Could really do with spec-r intercooler but this time of year should not be a problem!
Could really do with spec-r intercooler but this time of year should not be a problem!
25-10-2010, 10:42 AM
#113
The flow limits of the turbo make attempting to hold onto power very far up the rev range a futile exercise, so I would imagine that the cam is more about making it less laggy, maybe Mark will give us some info though, although I doubt he'll want to put any figures to it!
25-10-2010, 10:49 AM
#114
If mark makes it work in a different way to what iv said im sure he will say??
cheers danny
25-10-2010, 10:53 AM
#115
Upping the exhaust cam will be to make the car hold a bit more boost up the top and get the power to hold on a bit longer,it wont help anymore with lag infact you will probably let go of say 20-30lbft at the bottom to gainsay 20 hp at the top but imo a good idea if your speccing the engine to go over 500hp so a fair trade of...
"downing" the exhaust cam conversely though can make the opposite effect, and is what I would imagine Mark has done here, put a milder cam in to allow the engine to respond better lower down, with very little impact at the top as the turbo is limiting it there anyway.
Bit more to it than just more or less though when it comes to cam, its such a complicated subject in terms of the effect that different ramp rates have and the effect of more lift but less duration and vice versa, so they dont really just go "up" and "down" in that way, its a lot more involved than that.
If mark makes it work in a different way to what iv said im sure he will say??
25-10-2010, 11:05 AM
#116
[QUOTE=Chip;5151878]"Upping" the exhaust cam might increase boost slightly but if you are already on the righthand edge of the compressor map that typically wont result in anymore power, but will make it more laggy at the bottom end.
"downing" the exhaust cam conversely though can make the opposite effect, and is what I would imagine Mark has done here, put a milder cam in to allow the engine to respond better lower down, with very little impact at the top as the turbo is limiting it there anyway.
Bit more to it than just more or less though when it comes to cam, its such a complicated subject in terms of the effect that different ramp rates have and the effect of more lift but less duration and vice versa, so they dont really just go "up" and "down" in that way, its a lot more involved than that.
Oh sorry i thought you were talking an upgraded ex cam instead of a std one as mark as previously used at say cossierichs spec???
Its my understanding that mark has used std ex previously and thought you ment he was working with something above std in the ex to make a bit more power???
If not then no need to complicate the matter,just use a std ex witch works perfect on std head etc but with bigger ports,inlet plenum etc probably a good idea to try and trade of as iv said above to get the power a little higher up...
I do know how cams work chip as iv desighned a few myself now and tested lots on the dyno with them so i do understand what your saying hence what iv said...
cheers danny
"downing" the exhaust cam conversely though can make the opposite effect, and is what I would imagine Mark has done here, put a milder cam in to allow the engine to respond better lower down, with very little impact at the top as the turbo is limiting it there anyway.
Bit more to it than just more or less though when it comes to cam, its such a complicated subject in terms of the effect that different ramp rates have and the effect of more lift but less duration and vice versa, so they dont really just go "up" and "down" in that way, its a lot more involved than that.
Oh sorry i thought you were talking an upgraded ex cam instead of a std one as mark as previously used at say cossierichs spec???
Its my understanding that mark has used std ex previously and thought you ment he was working with something above std in the ex to make a bit more power???
If not then no need to complicate the matter,just use a std ex witch works perfect on std head etc but with bigger ports,inlet plenum etc probably a good idea to try and trade of as iv said above to get the power a little higher up...
I do know how cams work chip as iv desighned a few myself now and tested lots on the dyno with them so i do understand what your saying hence what iv said...
cheers danny
25-10-2010, 11:15 AM
#118
The devil is in the details though, 2 cams can look very similar on paper and drive totally different despite the figures not seeming like they would.
Trial and error is the only way of developing a camshaft IMHO, maths and previous experience can help get you into a ballpark, but ultimately its a case of sucking it and seeing.
25-10-2010, 11:22 AM
#119
The std spec cr head etc needs no help at all but as iv said ported head bigger coolers and inlet plenums id say a slightly bigger ex cam will help at the top where the other spec with this turbo runs out at say 6.5-6.7k..
cheers danny