TD42 aftermarket turbo - boost at low revs?

[Mark2]

Have been thinking about turboing my TD42 for some time now.
I've heard most aftermarket turbos dont start making usable boost until about 2500 rpm +.
This wouldnt be much good to me as I rarely rev it over 2800 and cruise/tow at about 2000-2200. Something which made power from about 1500 (or less) up would be great. Does such a setup exist?

[bogged]

I've heard most aftermarket turbos dont start making usable boost until about 2500 rpm +.

Manure. Pure Manure.

[Mark2]

I've heard most aftermarket turbos dont start making usable boost until about 2500 rpm +.

Manure. Pure Manure.

That was very helpful. Thanks

[Red Rover]

All depends on the turbo. Depends on the vanes, size of turbo etc. Mine is a DTS and starts boosting at around 1300-1500 revs. Very little lag. However a mates has a safari and it has a fair bit of lag but produces big power at higher revs. Guys that that run smaller turbos ie switzers seem to develop power down low put tail off up higher, from cars I've driven and what other friends have had.

Cheers

[GutSquisher Media]

Quite right Red Rover, the size of the exhaust turbine will dictate when usable boost is generated. The Denco unit for the TD42 seems to generate boost quicker around 1150 to 1250 but misses out on the higher power outputs the other aftermarket turbos quote.

I would say if your towing you would be best to have the boost earlier than later.

[bogged]

I've heard most aftermarket turbos dont start making usable boost until about 2500 rpm +.

Manure. Pure Manure.

That was very helpful. Thanks

You heard that, I was telling you that its crap. not hard to understand really

[spannercrab]

This is not neccessarily true ... it all depends on engine load. I have the AXT/Garrett setup and find that, while driving normally, boost doesn't come up to 10psi until quite high in the rev range (2200+), then falls off as the engine revs increase.

While towing, boost comes on much faster and at lower revs - although full boost wouldn't be achieved much below 2000 ...

At 80-100kph (approx 2000-2250 RPM) in 5th gear, full boost is easily achievable by increasing the fuel rate (i.e. accelerating)

For towing, however, I would suggest that the larger compressor/turbines are the ones to go for, as it's the engines natural torque curve you want to take advantage of - it would be no good being on full boost at 1000-2000rpm and not able to develop power in the 2000-4000rpm range, which is really where you need it most (imho).

Certainly the AXT system comes into it's own when towing, whereas it doesn't provide such a noticable performance boost when not under load.


Different systems for different applications essentially - all turbo systems have tradeoffs, so it all comes down to what you want to do with it ...

[GutSquisher Media]

Sorry spannercrab I didn't mean full boost at low rev's I meant usable boost which people will disagree with is, between 2 to 5 psi (flame me).

[Red Rover]

If i am on the flat and full revs at 4500 rpm it will not drop off on the boost. HOWEVER a ball bearing turbo seems to spin up real quick. Just finished experimenting with a number of turbo's and the ball bearing unit blows them all away. Shit the ute goes so hard i can't grab the gears quick enough. Squealled the wheels in third i kid you not. Engine revs real quick and has power right up past 150kph. If I keep the maverick I'll be getting another ball bearing turbo and using one of them for sure

[meiamaro]

Wouldn't boost at any rev be subject to throttle load?
More throttle more boost,light throttle lower boost
because of the air/fuel mix ratio ectect.

[Mark2]

t to take advantage of - it would be no good being on full boost at 1000-2000rpm and not able to develop power in the 2000-4000rpm range, which is really where you need it most (imho).

.

Does this mean that once full boost is developed, say by 2000 rpm, that the motor cant produce additional power as a result of the turbo? to put it another way, would it drive the same between 2000-4000 as a n/a motor? I dont know much about turbos but would of expected it would still be a lot better between 2000-4000 even if full boost was reached by 2000.

[bushy555]

If i am on the flat and full revs at 4500 rpm it will not drop off on the boost. HOWEVER a ball bearing turbo seems to spin up real quick. Just finished experimenting with a number of turbo's and the ball bearing unit blows them all away. Shit the ute goes so hard i can't grab the gears quick enough. Squealled the wheels in third i kid you not. Engine revs real quick and has power right up past 150kph. If I keep the maverick I'll be getting another ball bearing turbo and using one of them for sure

I'll also agree to all the above.
Installed a ball bearing DTS turbo, intercooler and 3" straight thru on to me 99 ute the week before christmas. Yep - took me the entire week of arvo's to install it. I run 35's with standard 4.1 ratios. It is incredibly *fun* to drive now. I cant even imagine what it would be like with the correct diff ratio's (4.66's) in it. Be a drag car.... or close enough to it. I believe that the DTS turbo opens the wastegate at 12psi. The adjuster that came with the intercooler kit is currently set to dump at around 8psi --- and struth the old girl goes well now. I easily drag off me mate (Maverick, 4.2 Petrol with extractors, 35's with 4.66 ratios). The guage still shows she'll still hit 12psi when at 3500+ rpm in 3rd. And other best bit? The note from the rear...

This dang turbo also took me fuel consumption from 19.5 litres/100k to around 14.5. No joke! A quick 300k trip at 85kh consumed 36 litres (around 13 l per 100k).

Best flippin money I've ever spent!
So: a public big thanks to MQHOON!

[Snatchy]

bushy555 - when you say you installed a ball bearing DTS turbo, is this just the standard turbo in the standard DTS kit? or is it a modified turbo, or something else? i just thought all the standard kits (AXT, Denco ,DTS, Safari) were non-ball bearing. I would be interested in a kit with a ball bearing turbo....
Thanks

[spannercrab]

Does this mean that once full boost is developed, say by 2000 rpm, that the motor cant produce additional power as a result of the turbo? to put it another way, would it drive the same between 2000-4000 as a n/a motor? I dont know much about turbos but would of expected it would still be a lot better between 2000-4000 even if full boost was reached by 2000.

No this is not the case at all - with a sufficiently sized turbine / compressor assembly. However I am suggesting that with a turbine which is too small (i.e. is able to adequitely develop sufficient airflow for the engine to consume at say 1000-2000rpm, and hence has the characteristic of spooling faster), however it's efficiency drops off after that. Too large a compressor will get you boost too late in the rev range to be useful. Everything is a tradeoff - just like an engine, the turbocharger has an efficiency curve based on it's wheel sizes and A/R ratio - too small and it won't be able to shift as much air volume, too big and it won't be able to spool when you need it.

If the compressor were sized inadequately - even with the wastegate welded shut, the boost (and airflow) would not increase past the compressors maximum output. Conversely an inadequately sized turbine (or mismatched) will not have the capability of delivering enough power to the compressor, thereby effectively limiting airflow and boost.

An adequately sized compressor and turbine combination, along with the housings, should be capable of delivering adequate airflow through the entire useable rev range.

Useable boost starts much lower than your quoted figures (from the AXT kit) - on full load the boost starts at around 1500rpm - give or take - and acheives it's full 10psi (which is where the wastegate opens) by 2000-2200rpm. What one would consider "useful" boost is a matter of opinion: to me, any boost is pretty handy!

So the short answer to your question is: The turbo still assists beyond the full boost "limit" - which is a function of adequate sizing.

I find that mine really performs on the highway while towing - it's where it is "in its zone" - or most efficient operating range. Going up a slight incline, putting the boot in (at 100kph I'm doing 2250RPM) results in nearly instantaneous boost and allows use of all the power available (and by this I would suggest that this is all, or a greater portion of the available fuel) to get up the hill.

With no load on the back, it doesn't spool nearly as readily, and the power increase is not nearly as noticable.

Fuel economy has increased while towing from 18l/100 to 13l/100 typically - although this is weather and terrain dependant ... anything in between is still possible.

[Josh n Kat]

i'd like to hear more about these ball bearing turbos.....

i know the street boys have been using this technology for years, why havent we been onto this earlier?

i'm looking to do a diesel conversion and turbo's the only way to go! if i picked up an N/A motor with say 250 000km on it what are the kind of thigs i should look at to make sure it'll be right to turbo? i'm only saying this cause if its sitting out of the car it'll be easier to say do the rings on it and bearings and stuff. and on the subject of turbos, would it be cheaper and better to buy a full turbo kit or to put something together myself such as custom exhaust manifold and intercooler piping? the street boys are making custom manifolds all the time, why dont we? they'd make the turbo run more efficient meaning more power! certainly sounds like a ball bearing turbo would be the way to go, thats for sure

[embryo]

I find it irrelivent when people say" It all depends on the type of turbo".
This statement is crap for the simple reason that any turbo you purchase is going to work, most turbo's out there will give you boost at around the 1600RPM mark and up because this is the nature of the TD42.

[spannercrab]

Hi Josh,
Ball bearing turbo's are meant for fast spool up times - typically in a diesel this is not as relevant as a high reving petrol engine when turbo lag is more crucial. For the considerably higher price tag - I don't think it's worth the extra $$.

I don't think it would be too hard to make up a custom manifold for a TD42 - space is at a slight premium owing to the limited space you have available between the engine block and LHS guard, so some care would be needed.

If the engine is in good health (good compression, good oil pressure, properly atomizing injectors and properly set up pump) then turbocharging shouldn't be a problem.

In terms of costs I would suggest that if you were to do everything with new parts yourself, then you would be hard pressed to even come close to matching one of the commercial kits - for arguments sake a Garrett T3 cored turbocharger - which wouldn't be quite as well set up as the custom jobs that are available for the TD42 - would run you around the $1500 mark, plus custom mandrel bent manifold ($1000?) mandrel bent compressor hoses, silicon joiners, custom braided line for oil and water, various braass fittings, clamps etc. Certainly the second hand route may serve to save a few crackers ...


Cheers

[spannercrab]

I find it irrelivent when people say" It all depends on the type of turbo".
This statement is crap for the simple reason that any turbo you purchase is going to work, most turbo's out there will give you boost at around the 1600RPM mark and up because this is the nature of the TD42.

If this were the case, then all bikes, cars, boats and trucks would all use the same turbocharger - because they all would work just the same as each other.

Try and put a Garrett GT70 cored hairdryer on a TD42 and you would be lucky to move the blades, letalone move any air on the compressor side.

A turbocharger is specifically matched to a very tight operating range - everything is a tradeoff - yes while it's true a smaller turbocharger (than would be the unobtainably "perfect" size) may be on boost at 1500, so would a larger size turbo - the differnce being that the smaller one would be near the end of it's capacity, the larger one would be closer to the start of it's operating range, and be able to deliver more toward the higher rev ranges - the tradeoff being that the smaller one produces more boost faster at the lower speed - and therefore the lag is more apparent on the larger one.

Even the manufacturers who make the kits will tell you that their turbocharger is more suited to a particular application.

[Hoonz]

i've got a highflowed T3 (same as VL turbo) on my GQ ... turbo lag is least of my worries ... power is there through the rev range ...

if ur so worried about turbo lag on a diesel bo buy a V8

[spannercrab]

I'm not worried about lag - I'm just making the distinction that there are efficiency and performance differences between different types of turbo's and a turbocharger should be matched to it's application for optimum performance for that particular application.

Lag is a good thing ... if you don't have a turbo, the whole rev range is lag ...

[GUte]

Would'nt the difference between the turbo types be that ball bearings would just spin up quicker but not make any more power?

[Josh n Kat]

yeah thats why i was thinking that a ball bearing turbo wouldn't be that bad cause you could have a slightly bigger turbo for more top end power but cause it spins easier it would still pump out boost earlier.

Have most of you guys just put an aftermarket kit on or has anyone done a custom job? as far as manifolds go, there's plenty of room for a trick manifold

[xenith]

i have a high speed ball bearing turbo no my gq off of a petrol eng. under load useable boost comes at about 1150 . but have found can get boost (5psi) free reving eng to 2200rpm makes for quick take offs turns v8 boy`s heads. any one at north coast woodpecker hillclime would have seen it was first car to get to top that day. it will smoke up 36" tyres on road no problems.

[Hobbz]

anyone got some specs on those ball bearing turbos ?

[vn15]

anyone got some specs on those ball bearing turbos ?

Have bought a new Garrett GT 2871R dual BB to mount on my modified GQ 2,8 TD. I think the turbinewheel is 47mm and comp. is 52mm.

The A/R is .60 and .86, comp and turbine respectivly.

Have not mounted it yet, but from what I have been told very quick response compared to one with bushes so should be good.

I believe Kym Bolton is running a big BB turbo with an external wastegate in his GU Ute.

[Hobbz]

Have a mate that has put a similar ball bearing turbo and a bigger intercooler on a 2.8 GU, 230 hp flywheel
But i would like to hear what you think about the new turbo when you get it on there ....
But i would still like some specs on a ball bearing turbo for the TD42, i have another mate that's looking for a turbo kit for his ....

[spannercrab]

Probably the GT35R or GT42R frame Ball Bearing turbo's would do the trick.

As far as housing sizes (A/R), compressor and turbine wheel size goes, these would need to be calculated based on HP requirements, where boost is achieved and maximum RPM @ full boost to calculate the most efficient match.

There is no "standard spec" turbo for the TD42 - it depends on what you're after - the kit manufacturers such as AXT, Mike Vine, Turboglide, Denco, CAPA etc. all use different size turbo's with different ratio's and frame sizes depending on their "ideal" calculations.

[BOB_1]

Ok - been following this thread, I have a GU TD42 99 NA, I want to turbo it. It's not often it goes above 3000 rpm, but I want something that will pull comfortably in 5th (which at the moment is 2200rpm 110 is 2500) on highway driving but will still pull down low not too far of idle. Am I better putting a kit together myself (roller bearing turbo, custom manifold etc.) or just buying a kit. If a custom kit - what turbo do I buy that would suit?

[Mark2]

Have been looking at some dyno results. The turbo glide kit seems to produce torque gains from fairly low revs. They use km/h instead of RPM on the bottom of the graph so it could depend on what gear it was tested in. They deliberatly set them up to produce no more than a 30% torque gain for longetvity reasons - some of the other companies eg Marks Adaptors (might be an AXT kit) claim very high figures, t his might not be a good thing in the long run.....

[xenith]

my gq has 425000 kms on it turbo went on at 374000 over 20 months ago running 13 psi have had no probs yet just chang oil 5000 km,s eng reved over 4000 rpm all time still all good