Jump to content
SAU Community

Recommended Posts

did u try a 16psi run and see what the results on that was?? maybe then overlap it with ur current map...then see whether the 4psi extra boost is worth the extra stress on the motor because it may just be generating heat and posibbly 2-3 kw per psi..i think the guys are on the right track here....good work!! thats huge power for a 2835 :)

We are of the understanding that that the wastegate spring is 18 PSI - cause thats the minimum boost we could get out out of it when the 3040 was on.

Now if the WG spring is rated at 18 PSI - why is it dropping to 16 PSI ? Spring might be worn.

The converse of this is - If it is a 16 PSI spring - why were we getting a minimum of 18 PSI on the 3040 (and the 2835) from 4000 RPM to 5500 RPM then the drop off ?

I reckon this is wastegate related......

Its now a $$ versus HP gain decision on whether to go chasing it down.

OK - I didn't get a copy of the test run with WG closed - but this is what the Power curve looked like (you can see what I mean bu the experly applied MS paint job I did on the graph)

2835_dyno3.JPG

With the Wastegate and EBC working 100% on the 20 PSI run, I would have expected a curve like this

2835_dyno4.JPG

Am I dreaming ???

We are of the understanding that that the wastegate spring is 18 PSI - cause thats the minimum boost we could get out out of it when the 3040 was on.

 

Now if the WG spring is rated at 18 PSI - why is it dropping to 16 PSI ? Spring might be worn.

 

The converse of this is - If it is a 16 PSI spring - why were we getting a minimum of 18 PSI on the 3040 (and the 2835) from 4000 RPM to 5500 RPM then the drop off ?

 

I reckon this is wastegate related......

 

Its now a $$ versus HP gain decision on whether to go chasing it down.

correct me if im misstaken? u put this turbo on...then send 20+ psi through it??? OR does the tuner gradually raise up the boost pressure when they tune for it???

whats the boost reading when the e-boost is switched off???? wouldn't this tell u exactly wether the spring is worn or not rather then going off ur last turbo????

how can u justify thats its a 16psi spring when tryng to send 20+ psi through it???

can u give more info into this matter?

I'm not trying to justify anything - The wasegate was bought pre-loved and we didn't know what sort of spring was in it.

With the 3040 minumum boost (ie e-boost turned off) was 18 PSI same as the the 2835 (18 PSI) but as you can see from the graphs, boost goes down to 16 PSI as revs increase. I'd prefer for it to stay at 18 or 20 PSI that's what I am sayaing.

All I am stating is the facts - and looking for answers.

all i wanted to know is does it behave in the same manner if u lower the boost (that is when eboost is switched of does it go up to 18psi then dropp to 16psi as well?....from the graph u posted it was initailly 20psi then drops to 16psi......if it is compressor limited generally where the boost drops off too ive noticed it to be most efficent...eg Buster's car... most efficient was 19psi....we squeezed 20+psi...it made a diff of 10kw max and with big spikes in the lower end, likewise with my car...what boost the turbo is rated to be efficient at is not always the case cause if ur making the power ur suppose to on it there no point screwing up the boost.......we were in the same boat as u now...

its not a $$$ for HP gain

it is when ur gonna send more boost through the turbo and eventually blow it

and having to buy a new turbo it will be a $$$ vs HP gain :D

Anywayz at 17-18psi im pretty confident that 2835 uve got will push out 275-285rwkw).....y bother squeezing anymore boost into it , isnt that the ultimate...low boost, big HP, less strain on ur motor, longer life if u want an answer i think thats it

otherwise get a bigger turbo...but as u go bigger Lag is the enemy as u should know with the 30/40.....how doe sthis turbo compare???

:)

Hey why not screw the wastegate in a bit and try it without the EBC connected, just running one line from the plenum to the bottom fitting on the gate. That way you can eliminated the wastegate from creeping open due to the EBC.. or see if it's the wastegate at fault.

Those Trust R gates are rebuildable, can always open it up to see if the diagphram is torn or catching on the side.

It's a fallacy that HKS turbos only start to make power at 18psi. If that were the case all their compressor lineup would have massive exducer diameters, and would be pretty laggy due to the increased inertia.

Having that massive spike on your "ideal" graph would just smoke the tyres. I bet it would be faster + more driveable without the EBC spiking the boost at lower RPMS, although at higher road speeds you might want that mid range spike.

If you really are after a combination that gives boost early, yet delivers more power up top your best bet is a set of small twins, like GT-SS or 2530. Merli's ~320awkw on GT-SS's would fit your criterea perfectly.

If you really are after a combination that gives boost early, yet delivers more power up top your best bet is a set of small twins, like GT-SS or 2530. Merli's ~320awkw on GT-SS's would fit your criterea perfectly.

Turn it up BoughBoy, as if he's gonna stuff around with setting up twins. Show us Merli's dyno to prove that his mid range is good.

Where was the boost reading taken from for the dyno input? Inlet manifold?

Adrian

Yes that's right :P

Umm but before the intercooler :)

On the pipe from the turbo to the cooler !

I think - well that is where the E-boost is plumbed in

I'll check where they tapped in the Dyno boost input

Yeah - nice smooth curve - unlike mine which is a bit all over the place.

Oh BTW - DB Don't forget that I have a big FO bar and plate intercooler to ensure that the so called 'hot air' is sufficiently cooled before it goes in the engine :D

Not taking ANYTHING away from Grepin - But I would have thought that a Externally wastegated, top mount 2835 would have performed a little bit better then a an internally gated low mount.

Thanks for posting Grepin - you have damn good power and nice curve. :D:)

Don't get me wrong - my car is still damn fast - It scares me more than the 3040 - cause on the street it is soo much more zippy. :)

Cheers fellas

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Have a look at that (shitty) pic I posted. You can see AN -4 braided line coming to a -4 to 1/8 BSPT adapter, into a 1/8 BSPT T piece. The Haltech pressure sender is screwed into the long arm of the sender and factory sender (pre your pic) into the T side. You can also see the cable tie holding the whole contraption in place. Is it better than mounting the sender direct to your engine fitting......yes because it removes that vibration as the engine revs out 50 times every lap and that factory sender is pretty big. Is it necessary for you......well I've got no idea, I just don't like something important failing twice so over-engineer it to the moon!
    • Yup. You can get creative and make a sort of "bracket" with cable ties. Put 2 around the sender with a third passing underneath them strapped down against the sender. Then that third one is able to be passed through some hole at right angles to the orientation of the sender. Or some variation on the theme. Yes.... ummm, with caveats? I mean, the sender is BSP and you would likely have AN stuff on the hose, so yes, there would be the adapter you mention. But the block end will either be 1/8 NPT if that thread is still OK in there, or you can drill and tap it out to 1/4 BSP or NPT and use appropriate adapter there. As it stands, your mention of 1/8 BSPT male seems... wrong for the 1/8 NPT female it has to go into. The hose will be better, because even with the bush, the mass of the sender will be "hanging" off a hard threaded connection and will add some stress/strain to that. It might fail in the future. The hose eliminates almost all such risk - but adds in several more threaded connections to leak from! It really should be tapered, but it looks very long in that photo with no taper visible. If you have it in hand you should be able to see if it tapered or not. There technically is no possibility of a mechanical seal with a parallel male in a parallel female, so it is hard to believe that it is parallel male, but weirder things have happened. Maybe it's meant to seat on some surface when screwed in on the original installation? Anyway, at that thread size, parallel in parallel, with tape and goop, will seal just fine.
    • How do you propose I cable tie this: To something securely? Is it really just a case of finding a couple of holes and ziptying it there so it never goes flying or starts dangling around, more or less? Then run a 1/8 BSP Female to [hose adapter of choice?/AN?] and then the opposing fitting at the bush-into-oil-block end? being the hose-into-realistically likely a 1/8 BSPT male) Is this going to provide any real benefit over using a stainless/steel 1/4 to 1/8 BSPT reducing bush? I am making the assumption the OEM sender is BSPT not BSPP/BSP
    • I fashioned a ramp out of a couple of pieces of 140x35 lumber, to get the bumper up slightly, and then one of these is what I use
    • I wouldn't worry about dissimilar metal corrosion, should you just buy/make a steel replacement. There will be thread tape and sealant compound between the metals. The few little spots where they touch each other will be deep inside the joint, unable to get wet. And the alloy block is much much larger than a small steel fitting, so there is plenty of "sacrificial" capacity there. Any bush you put in there will be dissimilar anyway. Either steel or brass. Maybe stainless. All of them are different to the other parts in the chain. But what I said above still applies.
×
×
  • Create New...