Had another Dyno day today (RR) and made peak power of 230BHP ATW @1.35bar or 275bhp at the fly (based on 20% loss)

It was a let down as I have previously made 260bhp (fly) on the standard turbo at 1.1bar - just 15bhp less

Mods I have, SIP, Evo 6 FMIC, 3" exhaust (decat), 75mm DP, external wastegate, (HKS 2535)GT2871R compressor wheel machined into T4 hat with stage 2 .48 T3 exhaust side.

Something just isn't right? I have also lost torque

The 265 on the standard turbo had no external gate, or 75mm DP either.

People are telling me cams but by inspection they look fine.

The turbo shop don't think it's the problem - this is now on the thrid variation, what with a stage 2 exhaust turbine, and going from the T04b wheel to GT2871R wheel to try and fix this problem etc

Bottom line I am running 6psi more boost 5250rpm for an extra 15bhp. I have got a heap more lag and lost alot of low down BHP - the headline figure is better but the power is down 50bhp at 3400rpm

The point that peak power is both times at 5250 makes me think the motor can't breath from some reason.

Dyno graph showing standrd turbo at 1.1bar and HKS at 1.35bar

Thoughts?

When you checked the cams, did you take the rocker cover off and check the wear indicators on them?

I know Vas said he had issues with his air filter hindering him, so another route, unless you have a beast of a filter

I have a Apexi Airfilter, with and 85mm intkae and 3inch intake all the way to the 3inch hat. I guess the air filter could be blocked? though I had it cleaned 1500miles ago (before winter)

They have wear indicators??? got a pic

I do, but not to hand, but it's easy to see. Whip the cover off and look at the edge of the cam lobes and you can see chamffered edges either side, just need to check that the main lobe isn't flush with it, if they are, then your cams have gone

Whats the afr? All your mods are spot on btw, so no reason why you should be down on power. Think beggars is on the right lines. Esp since its affecting where power is made.

Ross

Ok, found a couple

1
2

Ross, the mods should be giving more power than that. Ragz85 from Estonia was getting 330bhp with similar mods (had a tubular manifold and stock internals) and was making 330bhp

Sorry. I meant the mixture of mods, like there is correct size exhaust, proper fmic etc etc. The power is down i agree. My mistake for not being clear.

Ross

Cheers for the info Begbie/Ross

AFR was about 12 - 12.3 was the leanest it got on boost and that was at 6000rpm

So its not overfuelling.

Ross

Another sign is metal filings around the edge,
http://i50.photobucket.com/albums/f328/danhgt/S6000918.jpg

I think the peak number is pretty okay. You are probably pushing the stock manifold to extreme limits. Tubular manifold on my car made a HUGE difference.
A tubular manifold will perhaps give you a peak at higher rpms, but I still think that 0.48 a/r really restricts engine breathing because of backpressure.

You seem to have a bit too much lag. (I have less lag than that and im on 0.63 a/r exhaust)
Only thing that pops up in my head as cause for lag is either something with cams/cambelt or a boost leak. (Or maybe even exhaust leak)
To be sure it isnt caused by turbo you could always change to a stock 16vt turbo and see if you still have problems. (If you have the time :-) )

I really dont see the point in having 0.48 a/r. Even if its slightly laggier with 0.63 you really never drop below ~4500 rpm when you race.

Its a .48A?R exhaust housing but it is stage 2 shaft and wheel, apparently in real terms it's more like a .55 (mid way between a .48 and .63) so i'm told

Dink tells me his 16V grale made 411bhp on the standard cast log manifold (same as coupe) so don't think it's that but could be wrong.

Maybe I have a cam timing issue as well?

sry to hijack but is it the surface on all tap of cams or only where the base rod is painted??

ie are these worn?
http://i201.photobucket.com/albums/aa11/tohmahawk/CIMG1927.jpg
http://i201.photobucket.com/albums/aa11/tohmahawk/CIMG1928.jpg

just back from Athens, looking at your graph Paul.

I doubt it's the exhaust manifold to blame. Yesterday, went to RR my car again together with a stock 16VT with EVOCARS chip (modified based on last weeks RR data) and a BIG turbo and freeflowing exhaust/from turbo down. Made over 300bhp wheel and it was running dry (AFR 13+) due to either injectors or pump (stock items) maxing out on 1.3bar.

From my last few days experience with RRing my car and a couple of more, and based on the fact that you had decent fueling on (remind me) stock injectors, fuel pump wiring mod and nothing else (and we were running dry on modified EVOCARs chips also on stock pump) I'd point out
* restrictive induction
* turbo

Mind you all the cars we RRed we removed the SIP from the turbo and had them run completely open (this fcuked up fueling on mine as it was tuned to the existing restriction and without it it wasn't rich enough to make power).


Anyway, it's an easy enough test to remove the whole filter assembly (from the turbo) and drive around to see if it feels like it's picking up better, boosts earlier, drying up from fuel- cannot see this one without a wideband though. Mine made a hell of a difference without the filter.

The second possibility (turbo) is obviously much more difficult to assess though... Still a bit confused as it seems that your engine is not getting enough air in (else you'd be running dry with crap AFR like we did
You on a 3bar fpr from a 20vt or the stock 2.5bar one?

V.

Saint, what stuff did you use for cleaning the Apexi filter?

OK. With that a/r it shouldnt be the restriction.
Due to the design of the stock manifold, I really dont think you should be using it for high effect output. (Reminds me of saab 900 manifolds, wich were glowing red after you took the car for a ride :-), not very effective)

Freddan -I took it to a commercial sonic air filter cleaner (they clean truck filters which are super expensive and so are cleaned rather than replaced)

Yeah Vas - stock injectors with the 3 bar FPR, pleased I have it or I think I would be lean. Have the wiring mod but just a standard pump.

I can't see it being the intake, it's huge. on the standard turbo it was a 2.5" SIP, it's now a 3" sip.

I think the next step for me has to be cams and a bigger turbo. Dink has told me the turbo should be fine but I am running short on ideas

Took the cam covers off today to do an inspection - are these alright - they look a bit worn on the surface but not compared to the wear indicators

I say that because at the peak of the lobe they are deffinately marked and there are circles (like the inside of a tree when you cut it down) but they don't seem worn compared to the indicators - it has done 110km's so they won't be prefect

The number 1 lobes have about 5-6 circles(tree trunk type) which are the worst I could see but I didn't turn the motor over with the cam cover off.

I'm not sure as they still seem to be fine looking at the indictors begbie metioned.

Is there wear here and is it enough to explain my low BHP issues

i'll try and get some better pics if these are too hard to tell

trying to show tree rings

tree rings again

wear indictors look o.k though?

best of the bunch
scuffed or wear on sides of lobes

so, doesn't look like cams wear then Paul...
which unfortunately leaves us with turbo probs.
Unless someone comes up with a better idea

V.

Since my last RR - were I made 250bhp at 1.1bar, compared to this time 275bhp at 1.4bar I have had the turbo changed to a stage 2 turbine (.48A/R) - I have changed from a 34mm external gate to a 38mm gate.

Basically I reckon I would have got the same power on the old turbo just by uping the boost to 1.4, and with the stage 2 wheel I have increased lag by 500rpm so it is actaully worse than before.

I have asked this before but can't remember the answer. What can a standard head and cams flow. Maybe the standard motor is just maxed out at 275bhp at 1.4bar on standard cams

I've heard of a grale doing around 400bhp (fly) with intercooler, T35 turbo, program et al (stock motor internals)
so probably would be possible to get something more. But again it all depends on the accuracy of the RR! Maybe the one you're using is a "tight" one. The only true measure is going to the same RR so you compare your own results. Now how it fares compared to other cars, god knows (and we shouldn't really be that bothered tbh)

V.