turbo techies knowledge wanted????????

[coxie]

hi i have a hybrid t28 turbo from what i am led to believe its the same that saw adrian cash get 382bhp @1.2 bar :roll: .with this fitted with a tubular manifold and custom fabricated turbo elbow, and all mapped up for say approx 1.4/1.6 bar and all the mapping will be done using a power fc what would you estimate for the following

what bhp should i expect :?:
what torque would i see :?:
what boost can the turbo handle :?:
any one got any info on this turbo...ie specs :?:

thanks in advance for all help 8)

 

[Anonymous]

hi i have a hybrid t28 turbo from what i am led to believe its the same that saw adrian cash get 382bhp @1.2 bar

there was/is a fair bit of sceptisism about that turbo being able to produce that amount of power

 

[nismoboy]

what bhp should i expect :?: at a guess i`d say about 380bhp using 1.6 bar boost.
what torque would i see :?: 320lbft

 

[coxie]

cheers for the replies..i thought that about the power ability about the turbo but in a chat with ian i remember him saying he thought it about right. :?:

 

[Anonymous]

but in a chat with ian i remember him saying he thought it about right. :?:

he would say that cause he built it
no other b*gger believed it though :lol:

 

[coxie]

very good point bruce have you any idea of what power it could see then.would you say it could acheive 360 bhp at 1.6 bar .if not what do you think

 

[Anonymous]

very good point bruce have you any idea of what power it could see then.would you say it could acheive 360 bhp at 1.6 bar .if not what do you think

unlike some i don't profess to being a turbo expert i leave that to people who make turbos as a day job :lol: but,at a guess,i'd say it wouldn't be that far away from 360bhp.

 

[coxie]

8) thanks for your input bruce much appreciated.

ps. what kind of difference does a tubularmanifold give to response/power delivery. :?:
do you gain power etc :?:

 

[Anonymous]

what kind of difference does a tubularmanifold give to response/power delivery. :?:
do you gain power etc :?:

i don't think you actually gain any power but it does help with the responses.basically it evens out the exhaust gas pulses to give you an even flow of gas thru the turbo which somehow speeds up the responses :?

 

[coxie]

8) so am i right in thinking that the faster and smoother the gas goes through the manifold/turbo the easy it is for the engine to utilise it.therefore gaining more bhp and more importantly imho torque. :?

 

[memski]

I'm sure there was a test done recently, log manifold vs equal length tubular, and the findings were that the log cast manifold had better spool up due to the shorter runners but restricted power output and vice versa for the tubular (i.e higher power further up the rev range).

Would be difficult to tell as I imagine most people here that have upgraded the manifold here have also changed the turbo too, whereas this test was on the same car where the only difference was the manifold.

 

[coxie]

i am keeping the same turbo as its only done 1000 miles but i am fully rebuilding the engine and box and will change the turbo elbow aswell as the manifold for the tubular one i have.

 

[Anonymous]

8) so am i right in thinking that the faster and smoother the gas goes through the manifold/turbo the easy it is for the engine to utilise it.

would certainly agree with that bit

therefore gaining more bhp and more importantly imho torque. :?

not so sure about this tho.no matter what,a turbo can only supply so much air,which will give X amount of power depending on size of turbo.i think torque production is based on cam profile,boost press etc,etc :?

 

[coxie]

so on a 2 litre rebuilt what spec cams would you recommend and what kind of torque would 1.6 bar give me.

bottom end will be lightened and balanced,forged pistons,lightweight flywheel,ported and polished head with cams** and then when all is run in will go for bigger injectors and afm with a power fc mapped for the above boost pressure. 8) :twisted:

OFF TOPIC:can a power fc be used to run a car in or is it best to use original ecu and then swap injectors afm and management all at once. :?

 

[Anonymous]

so on a 2 litre rebuilt what spec cams would you recommend and what kind of torque would 1.6 bar give me.

bottom end will be lightened and balanced,forged pistons,lightweight flywheel,ported and polished head with cams** and then when all is run in will go for bigger injectors and afm with a power fc mapped for the above boost pressure. 8) :twisted:

OFF TOPIC:can a power fc be used to run a car in or is it best to use original ecu and then swap injectors afm and management all at once. :?

my cams have always been a bit lairy and were criticised quite a bit :lol: but peep's have had good results with the hks 264/272.it's very difficult to try a guesstimate power/torque outputs for a given spec as you get different results depending on what r/r you go to,what it was like on the day blah blah blah.sorry if that sounds like a pathetic excuse :lol:

nothing to stop you using std ecu and injectors for the running in period as DP made me do that a couple of times.there's also no reason why you can't use the fc etc either.just means you'll have to do a re-map when it's all run in.personally,i'd go for the std ecu and injectors as the motor would be a lot nicer and cheaper to run during the run in period

 

[coxie]

totally under stand about the power estimate statement.so a good cam combination would be 264 from hks and a 272 from hks :? :?:

 

[mozza]

got a turbo technics hybrid on mine, (reckon you've got a better one if your gonna be running 1.6 bar though) but here is what I got a few weeks back during my dyno session.

hks pistons, 264 cams, L&B bottom end, P&P head,knife edge crank and all the usual bits etc etc.

at 1.4 bar(1.36 bar on computer print out) got 280.1 at the wheels (274Ft/lbs of torque dunno how that is measured though????) on Dyno machine, acounting for 27% loses around 355bhp roughly but turbo was dropping off after 5500 revs to 1.05 bar by 7200 revs. , think il be upgrading though eventually.
(standard injectors and no tubular manifold but with just FPR, standard ECU with hks AFR and ignition timing controller).

 

[Nad]

I'm sure there was a test done recently, log manifold vs equal length tubular, and the findings were that the log cast manifold had better spool up due to the shorter runners but restricted power output and vice versa for the tubular (i.e higher power further up the rev range).

Equal length manifold is more important on an NA car as it needs to pulse properly in order to 'suck' the gas out of the chamber. On a turbo car this isnt so necessary. In regards to lengths of tubes, uneven lengths like on rally cars produce better low down torque whereas equal produce it higher up the rev range.

Just gonna find a bit more on it now.

Nad

 

[Nad]

Below are a few quotes I have picked out especially which should help clear things up.

"For low RPM performance, a small diameter, long tube will give the best port velocity, and exhaust inertia. For midrange performance, a shorter length, larger diameter runner is best. For very high RPM, a very short, large runner is needed because restriction is the biggest problem at high RPM."

"The narrower the rpm range of the header, the more power produced at that point. The wider the header's rpm range, relatively less but more evenly distributed power will be the result. Typically, longer tube headers produce more bottom end power, as does smaller tubes. Low rpm designed headers typically trade off more of a loss at higher revs than gained at the lower levels."

"As stated in the beginning, only Non-Turbocharged engines can benefit from headers, due to the fact that the pressure in front of the turbo negates any potential for the scavenging effects, while the turbo blades "chop up" the pulses into a "woosh" of air after the turbo, hence there are no pulses left to work with. Typically, the shortest, biggest and the most free flowing exhaust behind a turbo is best."

"Headers generally have lengths of pipe (called runners) that are equal length, with these lengths so measured so as to cause peak torque at a certain RPM range. Long, thin runners will bump up low end RPMs and have a wide RPM band, while shorter, wider runners increase high end RPM performance with a narrower RPM band. The wide runners generally have the unfortunate effect of dropping low-end torque. Why is this? As the tail end of each pulse leaves the runner and goes into the collector, a high-pressure spike gets induced into the other runners in that header. Now, if this high-pressure spike were to hit the exhaust valve for another combustion chamber as it was opening (or already open), the result would be a backpressure transient that would pose a restriction to that pulse that was trying to leave. Narrow runners, on the other hand, give great low-end torque at the expense of high-end power. This is simpler to explain, simply because the runners are too narrow for more than a little bit of flow at a time."

L8rs

Nad

 

[coxie]

8) good work nad good informative read that.cheers