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turbo .ar turbine housings... .63 .81 .95 back to back


Mike B

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I am going to try and swap out my tubbie tomorrow using my existing 0.96 ar divided housing and existing 0.70 ar compressor side. We shall see if it feels any different.

 

you'll need to remap though, no?

 

My PHR Stage 1 has a .70ar divided housing :)

really.....? how sneaky! the early spool on your dyno chart was always a bone of contention for me.. you use 3" dp and no vvti yet you still outspooled my 35r.. maybe this is why...?

 

Meh, for 4cyl engines maybe. Corky of the Bell says you don't need them for turbos getting 6+ cylinder's impulses.

 

50/50 meth for water injection... I have still not run it yet - When everything is settled I will try with and without.

 

My colleague found the gaskets an hour ago.... two hours after I ordered another! two of them taped to kyles box in the packing area.. So now I have three :tongue:

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Hmm after a bit of investigation I find that my 0.96 A/R exhaust housing is in fact just that. NOPE not a divided housing but a single one. That firmly explains why I always insisted the car spooled real slow but stupidly strong when it did so. So when I scrabble the parts together to change the exhaust housing I will stick the 0.68 A/R housing that came with my tubbie on instead. I expect not to have to re-tune as looking at the wheels in both tubbies they are identical. They both fit both sets of housings. I actually now expect with my original compressor housing and my original exhaust housing to see utterly no difference in performance between my old HKS turbo and my new precision dbb turbo other than a slightly earlier spool. I will confirm as soon as I get the car on a dyno. After that I will re-dyno the car when I get the 0.67 A/R housing on (and expect a bit of a tune tweak)

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Hmm after a bit of investigation I find that my 0.96 A/R exhaust housing is in fact just that. NOPE not a divided housing but a single one. That firmly explains why I always insisted the car spooled real slow but stupidly strong when it did so. So when I scrabble the parts together to change the exhaust housing I will stick the 0.68 A/R housing that came with my tubbie on instead. I expect not to have to re-tune as looking at the wheels in both tubbies they are identical. They both fit both sets of housings. I actually now expect with my original compressor housing and my original exhaust housing to see utterly no difference in performance between my old HKS turbo and my new precision dbb turbo other than a slightly earlier spool. I will confirm as soon as I get the car on a dyno. After that I will re-dyno the car when I get the 0.67 A/R housing on (and expect a bit of a tune tweak)

 

Going from .96 to .67 will need a significant map change.

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Going from .96 to .67 will need a significant map change.

 

Oh I realise that but hopefully just swapping the turbo core over, looking at the wheels they look identical I am thinking that I won't need a re-map done for that (I'm only going to run it like that until the adaptor for my downpipe and v-band clamp pitch up). After I get the stuff I will be fitting the 0.68 A/R housing and then re-mapping. I will though, if I can get it to a reliable dyno put it on a dyno to see what effect changing the core from a journal bearing to a dbb is. Also shows me a direct comparison between the housings when I change them. I may even change the housing at the dyno to alleviate weather differences.

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...Also shows me a direct comparison between the housings when I change them...

So-called direct comparisons are not fair in such cases.

What are you gonna do, run an optimised setup against an unoptimised one?

...or run two unoptimised against each other? Doesn't make sense, does it;)

 

It is best to take some time optimising fuelling and ignition for the new airflow situation.

 

Time the car with each setup, that will be a more fair comparison.

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So-called direct comparisons are not fair in such cases.

What are you gonna do, run an optimised setup against an unoptimised one?

...or run two unoptimised against each other? Doesn't make sense, does it;)

 

It is best to take some time optimising fuelling and ignition for the new airflow situation.

 

Time the car with each setup, that will be a more fair comparison.

 

Its about as fair as I can get it. An optimised 0.96 A/R setup dyno'd before I swap the housings out. Then with the 0.68 A/R housing the car retuned for that housing and optimised then the car dyno'd again?? How much fairer than that can it be? The atmospheric conditions will be identical, the rolling road obviously identical, no other factors like wear and tear or even different fuel. I fail to see what else can be done to make it any more a direct comparison?

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Guest TeCKis300

The turbine housing size greatly affects the volumetric efficiency of the motor at different rpm ranges. MAP tuning motors depend greatly on this assumed VE. Change the VE, and the MAPs will no longer be valid. MAF tuned motors measure the mass of incoming air directly and will self account for changed motor VEs.

 

The only way to do a valid comparison is to retune for each.

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OK I am obviously getting the point across wrong here. The car is tuned for the housing thats in there now! I will dyno on the day the car with that housing on there. I will then swap the housing and re-tune the car. Then I will produce a dyno reading for the replacement housing. OK maybes a dbb tubby over a journal will make a nadge of a difference to the mappers plans but looking at my AFR's there's hardly a difference.

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OK I am obviously getting the point across wrong here. The car is tuned for the housing thats in there now! I will dyno on the day the car with that housing on there. I will then swap the housing and re-tune the car. Then I will produce a dyno reading for the replacement housing. OK maybes a dbb tubby over a journal will make a nadge of a difference to the mappers plans but looking at my AFR's there's hardly a difference.

 

I understand you and I think it would be a great test, looking forward to the results.

 

Where are planning to do this and who is going to be doing the mapping?

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.. I will dyno on the day the car with that housing on there. I will then swap the housing and re-tune the car. Then I will produce a dyno reading for the replacement housing. ...

Ah, it's clear now, my mistake. I thought you'd just swap housings and dyno again. ooops:innocent:

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This is my main problem. The car is now here in Holland. I think I am going to have to take it cap in hand to Arnout and ask him to do the job for me. (I upset him a while back so that should be interesting). Thing is the map on the car is technically the intellectual property of Dan Turner and as such I should remove that map before I go to see Arnout. Its not possible for me to get the car back to the UK in working hours for Dan to do the job for me this year.

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The .68 went on tonight,

 

I only took her out for a gentle run, made no more than .9 bar.. it was wet and slippy too.

 

She is spooling much earlier and the car feels stronger. Fueling was out, significantly; she was running lean initially.

 

the throttle response is still not as good as the gt35, but it is significantly better than the .95 divided.

 

Once the map is settled I will push the boost up, and look for any surging (terry told me to keep an eye out) and see if she tails off upper rev range.

 

Happy so far though.

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For goodness sake, get it mapped properly Mike

 

lol...

It took to the last set perfectly, target afr perfect through the whole range and egts were spot on.

 

When I took her out last night it was wet; still is now, and I could only use 1/3 throttle, so not much use, it may well not even dip that deep into the afr's when not under load. Don't worry, though it's in hand!

 

The trouble is if I took it to an hks specialist in the UK I would be FAR worse off... I doubt that anyone over here has the ability to set it up as comprehensively as it is now. I do keep in contact with Reg and next time he comes over we will meet up for a health check.

 

I did mail TDI north with system spec just to see what they would say. They didn't even bother replying.

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Got the car to 1.4 bar this afternoon, afr's spot on.

 

It doesn't pull as well as the '95 housing after 4.5k, but the response is a lot better, you get a lot more pull around 3.5-4.5 and there seems to be no tailback in power top end + no surging either. The spool is significantly better. I can live with this setup I think.

 

Unlike DB's experience I didn't notice any change in 1st and 2nd.. they are still miles off the power of the 35r.

 

EGT's, interestingly enough, are around 3-400 degrees higher with the .68 than they were with the .95.

 

Job done for now. Can I be arsed to try the .85? ummm not really! lol

 

I now have to go and fix the rest of my life; Got to the top of a massive hill last wed on the mountain bike and my chain snapped. Not so bad I thought.. at least I can freewheel home...

500 yards later, flat tyre... doh!! I spend more time on that stupid thing than I do on my car.

To top it all off I forced myself out in the rain and wind today to go kitesurfing. 30 minutes of screwing around, 3rd run in and my kite exploded. I'll need more than a puncture repair kit to fix that one.

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TBH mate, and after a good few hundered quid.. it's 50/50.

 

The 35 is like driving a stock car on steroids.. the 4088r in whatever guise is just a one trick pony... you can't drive it.. you can find a big bit of road and hang on, but that's it.

 

The 35 you can drive round a track like a caterham, throttle response and immediacy of it in 2, 3, 4th is just stunning. It's significantly quicker because you can put power down precisely where you need it. I can see why Terry went for this set. The 4088 is like tring to knit a jumper with kenny everitt's hands.

 

I'm sure you could put a nitrous bottle on the 35 to keep yourself amused!

 

I will keep it as it is for a while but may go back to the 35 eventually.

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