[Mk2] [Turbo] GT35R dyno dillema updated with 4th gear Datalogit 8 May

[george_m]

Rev 3 Engine details
PFC and datalogit
GT 35r bb with .63 ar turbine .70 compressor 4" inlet HKS filter
Tial 38mm v band wastegate venting back into 3" down pipe
JE 8.5 :1 pistons
Eagle steel rods
ACL race bearings
ARP head, mains and flywheel
ATS adjustable timing gears
HKS 272 inlet set 110 deg oe cams back in
HKS exhaust set 103 deg
Walpro pump
Denso 880
Large BMIC twin fans 3" pipe work
Eagle valve springs
OE valves
OE inlet and exhaust
3" downpipe and KO racing full 3" single exhaust

Problems

really lumpy unstable idle
only 281 fw bhp @ 7432 which is 100 plus fwhp down on my old set up with TD06 and standard cams
Boost creeps on dyno but ok on road which look like I need larger wastegate pipe or maybe convert to screemer
I have got some data logit capture so will post these up soon
I have changed the injectors back to the 540 but still crappy idle
I now believe the problem is the cams or cam timing, are these cams too aggressive for my build or am I a mile out on the degreeing, should I put the old cams back in and get that set up right first, I cannot see that ignition or fuel would make that much difference
Help please engine bulders

[jimGTS]

why 800cc injectors at 56%?
should be like 67% no?

potential cam issue id guess if you got rough idle as well...

only thing i can see in setup that is likely to serious effect power if its miles out.

i dont know anything about installing or degreeing cams tho, so im prob not the best person to ask.

hope you sort it.

[mark239]

has it actually been mapped ? Of course ignition timing makes a massive difference, but the lumpy idle could be your timing, or you could have a mad amount of blowby or melted pistons of course.

Did you degree the cams properly, ie NOT using the timing mark on the engine but finding real TDC with a piston stop?

[ashley]

Check the base ignition timing as a starter for 10 (did you have the dizzy off?), then look at your cam timing- make sure you've referenced TDC correctly...

[george_m]

why 800cc injectors at 56%?
should be like 67% no?

potential cam issue id guess if you got rough idle as well...

only thing i can see in setup that is likely to serious effect power if its miles out.

i dont know anything about installing or degreeing cams tho, so im prob not the best person to ask.

hope you sort it.

thanks

My 540 injectors were set to 85 @ 0.1 as I forgot to mention I have an uprated ATS fuel pressure valve so I took 15 from the 67.
The dyno wideband showed 11.6 at 5500 and strated getting to around 12.5 :1 at 7000 rpm and was still getting weaker as the revs rose.
I do not think this would account for such cause such a power loss
George

[george_m]

has it actually been mapped ? Of course ignition timing makes a massive difference, but the lumpy idle could be your timing, or you could have a mad amount of blowby or melted pistons of course.

Did you degree the cams properly, ie NOT using the timing mark on the engine but finding real TDC with a piston stop?

Hi no I used a dial gauge to find tdc with a short pencil down the plug hole and set up a degree disc mounted to the crank pulley and a fixed pointer on the block, noted 50 thou btdc and 50 thou atdc and used the centre of this. This was all with the engine out and I checked an double checked my valve timing and adjusted the ATS gears.
Timing numbers are simular to my TD06 setup but with a couple of degrees taken out to lower the knock levels recorded as I used to run a little cvl turbo additive before
The car is not breathing heavily and has only done 250 miles so hopefully the pistons are all ok
George

[george_m]

Check the base ignition timing as a starter for 10 (did you have the dizzy off?), then look at your cam timing- make sure you've referenced TDC correctly...

Hi
I did as above and tried to set to 10 degrees with TE1 and E1 of the check connector linked with a wire, however the timing was still dancing about as I the idle was so up and down so I did not get a nice steady fixed strobe
George

[craig_mr2_mk1]

Who has Mapped the car previously? Would it not be worth ringing who ever Mapped the car to come and have a look at it?

[mark239]

Check the base ignition timing as a starter for 10 (did you have the dizzy off?), then look at your cam timing- make sure you've referenced TDC correctly...

Hi
I did as above and tried to set to 10 degrees with TE1 and E1 of the check connector linked with a wire, however the timing was still dancing about as I the idle was so up and down so I did not get a nice steady fixed strobe
George

TBH, I never found the standard stupid timing reference to be reliable, thats why I used a degree wheel in the end.

Result was no more random knock and rock steady timing at all revs

You can't expect the map for that other turbo to be remotely close to the requirements for a GT35. Sure the peak torque will be at a totally different RPM where you'll have your dip in timing etc

[george_m]

I'm thinking of putting back the rev 3 cams and trying that as I wander if the HKS 272 inlet cam is too aggressive for a standard head and inlet manifold, or I have just got the degreeing all wrong.
Just before the end of last years racing I did my best lap times at Castlecombe 1m 13.6 then I blew the head gasket. The set up is much the same except the turbo changed from TD06 to GT35r, the rev 3 cams to HKS 272 and 264 cams, same exhaust and bmic the injectors were changed but I have put these back in for now just for testing.

The same guy as last year tried mapping it, the first session I had massive boost creep leading to engine cut so that ended that session, I have reported and gas flowed the ATS T3 adapter for better flow and that help helps on the road but it still crept up on the dyno but now after 7200 rpm not 5000 as before. He thinks the cams as the idle is more than just hot cams lumpy and unstable and the power down is more than the few O2 and ignition settings he already tried.
So me thinks remove another variable put the old cams back in re time the ignition and see if if that helps the idle, if so try another mapping session

Its just pi##ing me off as I have had to cancel my first test day shake down and now my first race on this Monday and the next race is just a week later so its down to time

[mark239]

You've totally changed the VE of the engine, the mapping will be totally different.

Get it mapped.

I had one of those adapters too, I now have a proper manifold and wastegate (60mm). Just couldn't get it reliable with the adapter.

[Chris]

Stick the stock cams back in. Then re map it. I never had any sucess with 272's at all. I adjusted them, re set them, re dialled them and no matter what I did, my car made no power. Well, made a good bit more than yours but on stock cams Dave got some right advance in there. Drove lovely off boost too.

[greeny]

You've totally changed the VE of the engine, the mapping will be totally different.

Get it mapped.

.

^^ This.

[greeny]

Stick the stock cams back in. Then re map it. I never had any sucess with 272's at all. I adjusted them, re set them, re dialled them and no matter what I did, my car made no power. Well, made a good bit more than yours but on stock cams Dave got some right advance in there. Drove lovely off boost too.

I don't think the cams have much to do with his loss of power.

Did you ever degree them properly?

I know you and andy couldn't get them to work, but plenty of other people have

[craig_mr2_mk1]

Who is it who's trying to map it & what ECU?

I have to agree with Chris too that Rev 3 Cam's & some vernier pulley's are perfect for 500hp easy. Not saying that the your HKS Cam's are at fault because as Greeny says many many people have and still are Making good power using them.

If I were you I'd ring Ryan G and get him round too your house to try and get it Idling right first. I'll bet money on that if he can't get it too Idle he'll tell you why too. I believe he lives in Oxfordshire so I don't think that's too far from you is it.

[Chris]

I used my car mainly as a road car greeny. I had the cams spot on but drivability was crap at low speeds. I made 635bhp on stock cams and pulleys and off boost it was like a stocker. Dave reckoned I might of saw 700 with the 272s back in and larger injectors. But I did not want it to drive crappy off boost for another 70bhp.
Depends what you want. But do you really need 700bhp?? As a dedicated straightliner then yes. But for road and track use I would go stock.

[RyanRs]

Castlecombe 1m 13.6 then I blew the head gasket.

Cant see that happening on a rev3 mate. Perhaps this is the source of your troubles!? re-check your compression numbers / leakdown. Also, i have not read the whole thread but it appears you have not had the car re-mapped to the new turbo, this has to be done!

[bolton]

loose the 272's and chuck in some low lift hks 264's FTW!

[greeny]

I used my car mainly as a road car greeny. I had the cams spot on but drivability was crap at low speeds. I made 635bhp on stock cams and pulleys and off boost it was like a stocker. Dave reckoned I might of saw 700 with the 272s back in and larger injectors. But I did not want it to drive crappy off boost for another 70bhp.
Depends what you want. But do you really need 700bhp?? As a dedicated straightliner then yes. But for road and track use I would go stock.

Yeah i agree mate.

But i don't think the cams are his problem.

Saying that mines pretty good of boost to be fair, but it's 2.2l aswell which i guess helps.

The trouble is people blame the cams, when they just put them in straight up and don't degree them properly. Or just go on other peoples settings, when every engine/setup can be different.

I think 500whp would be too much for alot of tracks

Mine only makes 590whp and it'd be quite a handfull on track im sure, even though the power delivery's quite linear for a largish turbo.


George, have you had it remapped?

Or are you trying to run it on the previous map?

[Kongaroo]

Hi George - a possible cause for being miles out power wise is the base ignition timing. Before you try swapping out your cams you should get the base timing checked/sorted first.

What you need to do is go into Settings 1 using FCEdit and uncheck the box next to Idle-Ig-control and press update. This will make the car try to run at 10 degrees in a similar way to bridging the 2 diagnostic ports in the engine bay.

You should now be able to set the base timing to 10 degrees using the strobe light. Once this is done you can then recheck the Idle-Ig-control box, update and save. Then go back to the dyno to see if there is any improvement in power.

If you had been running extremely retarded ignition timing this could have contributed to your low power, idle and also boost creep issues. Hope that helps anyway

Btw what was the boost level when you made 280BHP?