Franco

iTrader: (2)

I said HOW you sarcy cnut!! not where!!

do you have to have a boss welded to the manifold? or is a probe inserted somewhere? ()........

Can it be shown on someone's dyno pictures?

Mike Rainbird

iTrader: (3)

Yes you do. Just get "someone" to take a picture when he collects his engine .

Rippers

Franco

iTrader: (2)

Ahh so its the probe added to the trouser part of the wastegate!!

So hows it measured on the road then?

Mike Rainbird

iTrader: (3)

Read my sarcy reply you numpty .

You just connect up a boost gauge and measure it like I said .

Franco

iTrader: (2)

I'll get me coat!

TiB

iTrader: (1)

This front with the .82 rear housing GT30... how does it differ from the .82 rear house'd GT35?


Lee

Mike Rainbird

iTrader: (3)

It's a completely different turbo. The GT35 0.70 a/r with 0.83 a/r turbine housing is a 600bhp turbo....

AJC

iTrader: (6)

well im getting confused now

rapidcossie

How long was each load point held on the dyno Mike?

TiB

iTrader: (1)

Is that a GT35 in the pic above then?

Lee

rapidcossie

sure thats one of the GT30's Lee

TiB

iTrader: (1)

All this gt stuff looks the bloody same to me lol

Bullett

iTrader: (2)

aint that the truth lee.gone are the days of recognising the t3,t34 and t4

Martin-Hadland

iTrader: (2)

The GT30 & GT35 turbos that I sell look identical on the outside, so with the air filter pipe in place you could not tell the difference. That's why that GT30 looks like your GT35 Lee!!

rapidcossie

GT35 Lee?

Something your not telling us?

McGoo 69

looks stunning!! would look alot better with the black comp mo's tho haha

glancy2081

stunning car and conversion credit to all involved

Karl

Hi Mike,

Interesting results from the engine dyno. Here are some of my thoughts....


1. Wastegate is returning to main exhaust. I have never done this, and find the 0.63 and 0.82 housings VERY similar for back pressure, where as on harveys dyno the two are clearly different.........however the power is very similar, exaclty as I have found.

2. The chances are my test engine had a considerably better head and cam setup than the dyno engine, and my engine revs to 8800rpm! We have held it sustained at 8500rpm whilst mapping with no issues. The engine in question is the sunbeam engine and is essentially a 700bhp engine running a GT30.

3. The dyno results in no way reflect the road characteristcs of the two turbos. The 0.82 is more laggy and lazy.

4. For thoroughness of testing I will bolt a normal 500bhp head to the sunbeam engine and retest back pressure readings and let you know what I find.

5. 137mph qtr mile terminal speeds with the 0.63 GT30 and no NOS shows its hardly down on power regardless of whether you believe the 530bhp claim! LOL

Gatecrasher

Will having the Wastegate not returning to main exhaust lowers the back pressure?

so if you do find that your test engine is more efficient, unless customers have the better head and cam setup surly there engines wont run as efficient as your 700hp one then no?

Ben

Mike Rainbird

iTrader: (3)

Hi Mike,

Interesting results from the engine dyno. Here are some of my thoughts....
Hoped you would reply, as I am always interested to see your findings, as they seem to be based on actual testing .

1. Wastegate is returning to main exhaust. I have never done this, and find the 0.63 and 0.82 housings VERY similar for back pressure, where as on harveys dyno the two are clearly different.........however the power is very similar, exaclty as I have found.
What effect do you think that feeding the wastegate into the exhaust will have? Are you measuring the back pressure in the same place? How are you measuring the back pressure (from a load site point of view)? I was surprised that given the back pressure disparity that the power was so similar .

2. The chances are my test engine had a considerably better head and cam setup than the dyno engine, and my engine revs to 8800rpm! We have held it sustained at 8500rpm whilst mapping with no issues. The engine in question is the sunbeam engine and is essentially a 700bhp engine running a GT30.
I don't doubt that for a second, as Paul's engine only has a medium port head, standard size valves, 2wd exhaust and EECIV inlet. Given your above statement, it seems unusual for you to claim 530-540bhp from an engine that is way off the air flow of your test engine, along with having the wastegate connected in a way that yours wasn't?

3. The dyno results in no way reflect the road characteristcs of the two turbos. The 0.82 is FAR more laggy and lazy. The 0.63 wins hands down EVERYWHERE.
I agree, you can't see anything other than improvements in boost threshold on the dyno (although you get a basic idea of what it "should" do from experience). The 0.63 a/r turbo is the one to have for a road engine, but I would be concerned at the back-pressure readings for one that is going to be used either extensively on track or in top speed running.

4. For thoroughness of testing I will bolt a normal 500bhp head to the sunbeam engine and retest back pressure readings and let you know what I find.
That would be very interesting to see - don't forget to use a standard inlet and exhaust manifold for direct comparisons .

5. 137mph qtr mile terminal speeds with the 0.63 GT30 and no NOS shows its hardly down on power regardless of whether you believe the 530bhp claim! LOL
That is very impressive, but without knowing the weight of the car, doesn't give any indication of power to weight to get a better picture of exactly HOW impressive . Can your reveal this?

In the meantime, thanks for taking part in this discussion, as it is always interesting when you are involved - especially when you are imparting technical details .

Mike Rainbird

iTrader: (3)

The engine is gradually built up to the rpm load site (both revs and boost wise) and once satisfied that everything is safe, a few seconds are waited for it to stabilise and then the "run" recorded. I would say the total length of time it takes from start to finish of each load site run is no more than 10-12s.

Karl

Hi Mike,

Regards comparing AJC's engine in terms of power to our sunbeam engine, the reason I estimated his power to be around 530bhp is because he uses the same 83lb siemens injectors and 5 bar map sensor on a L8 ecu as in our car. Hence comparing his fuel map to our sunbeam engine his engine is VERY similar in injector durations up to 7300rpm, (He also runs the same fuel pressure which was monitored during mapping) which is where the engine will be making peak power.

Back pressure readings are taken at the entrance of turbine housing.

I believe the external plumbing of the wastegate makes an improvement on back pressure BUT until tested that is only heresay and my opinion.

Gatecrasher

as you know Karl Pauls engine made just shy of 500hp on the dyno with no ancilirys so in car its going to be even less where are you quoting 530hp for andys engine in car as that would mean 550ish hp on a Dyno? do you put the extra 50hp down to your cam choice and head work?

thanks

PAUL_SHEP

Best thread on here for a long time, I am learning so much info that will no doubt have a direct impact on the choices I make in the future. Cheers guys.

Mike Rainbird

iTrader: (3)

Cool, that all makes perfect sense - I suppose the only bone of contention left is how you are measuring the power and what process you are using to measure the back-pressure (as in, how you are holding the load at different rpm points or if you are even doing it that way) ?

Goes to show how good your head is, as I know what had to be done to mine to achieve 500bhp @ 8500rpm .

Thanks for taking the time

Karl

Gatecrasher,

Yes there is no doubt the heads and cams on my 530bhp GT30 engines are better flowing than the 500bhp engine of pauls. My engines usually run solid lifter cams.

Beyond 7000rpm the GT30 cannot maintain boost, and is normally down to 1.8bar by 8000rpm where I usually see around 500bhp. The GT35 can however still pull 2.3bar at 8000rpm, normally showing power around 580bhp.

Again all this testing is on my own engines are EVERYTHING is monitered and tested including individual EGT'S.

Hope that info is helpfull.

Karl

Mike,

All measurement is done whilst mapping. To sustain load at say 8500rpm we load the car fully in 4th and hold the engine back on the brakes to maintain load at that particualr rpm. Obviously this is real world testing, and NOT the artifical dyno environment which can be VERY misleading.

Power readings are from Nobles, so of course are speculative, but I have sufficient experience of mapping and comparing specific map data to understand the effects and consequences of changes made whilst testing out on the road and thus can accurately quantify power gained or lost by comparing injection duration times on the same engine.

Stu @ M Developments

iTrader: (12)

Nice topic. Great input Karl.

Mike Rainbird

iTrader: (3)

Karl,
Perfectly adequate explanation - thanks for taking the time to post .

Obviously the only disparity we have are the power figures (but that is always the case conparing a rolling road's artificially calculated flywheel figures with engine dyno figures) and the back pressure readings (clarified by yourself) . Everything else we seem to be in agreement on.

A real shame that a run without the wastegate connected to the exhaust wasn't carried out on the dyno, as that may have shown a measured difference in back-pressure readings, as it would make sense for there to be less back pressure with a screamer pipe .

That leaves another experiment to carry out on a different day .

Very interesting comment you have made about the GT35 .

Mike Rainbird

iTrader: (3)

As your engine will be running the same wastegate set up as Paul's, you can see that the back pressure recorded would make it unwise to extend the revs beyond 7250rpm for any long periods, which in my opinion removes the need for solid lifters (you WILL still need some decent valve springs though and won't be able to get away with standard ones!).

Would be interesting to see if Martin and Karl agree .

Franco

iTrader: (2)

I believe the valve springs are not standard Mike! (double valve springs to mind).

Mike Rainbird

iTrader: (3)

You're sorted then .

The only issue might be is if the cams they like to use are only ground in solid lifter format. However, I'm sure they use readily available ones, so this shouldn't be an issue .

Franco

iTrader: (2)

I do hope so Mike!

Karl

Edited to say Solid cam profiles offer advantages over hydraulics at rpm beyond 7500rpm.

Fiecos Dan

Nice car AJC

and a Very good read.

Bullett

iTrader: (2)

i take it pauls engine is a harvey built one?

rapidcossie

edited to say after re-reading Karl's post that power could be had above 7500 on solids compared to hydraulics.

Fiecos Dan

So have you tested on same spec cams, but solid lifter spec?

Rippers

Yes it is mate