Blairm
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| posted on 14/3/09 at 07:59 PM |
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X-Flow back from Dyno
Hi Guys,
Had my car back on the chasis dyno as the head had been off to have valve guides fixed and a couple of crock valves sorted. I had also added an Aldon
Ignotor ignition.
Ran like a dog so I took it to the local rolling road tunner and they got it going nicely. Have not seen the bill but it took quite some time!!!
Anyway, it has come back with 100.5 BHP at the wheels (in NZ they do not seem to bother trying to estimate Flywheel BHP, but I guess this is about
125) at 5950 rpm. Torque was about 450-530 NM across the 4000-6000 range peaking around 4700.
It is running GT valves, 234 cam, twin 45's with 36mm chokes. Some porting as well.
Not sure of the exact compression ratio, but it will be nearer standard.
My questions are:
How do these torque figures compare to what people would expect?
Would I gain alot by going to custom or 1300 pistons to raise the CR in terms of HP and torque?
The dyno test stops at 6K, is this nornal? I regularly rev to near 7K and it keeps pulling. Could it be making at least the same if not more in the
6-7k range?
I was considering swapping to a 244 cam, but notice alot of ford guys on a South African discussion group seem to be using 254's. It really
only goes on the road on a trailer these days and I am sprinting most of the time.
In my class (1300-1600) I am running near to the top, but some of the better Jap tintops with good 4AGE's still have legs on me and I think
about 20 more HP would sort it.
A LSD would help as well 
I also notice on the graph the A/F ratio between 2K and 3K is between 15 and 16, droiong to around 11 by 4500 and then jumping to relatively stable
12.5 to 13 through to 6K. Are these big variations normal? Is 16 dangerously lean?
Pick the car up on Tueday (1 more run to check some new heat range plugs) and keen to querry the tunner but wanted some advice first.
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clairetoo
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| posted on 14/3/09 at 08:09 PM |
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Theres something amiss with those torque figures - 530 NM equates to 390 foot/pounds 
My last crossflow made 165 ft/lb's jst under 4000 - but it did have throttle bodies/distributerless and a much wilder spec 
Its cuz I is blond , innit
Claire xx
Will weld for food......
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Blairm
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| posted on 14/3/09 at 08:17 PM |
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Yes, You are on to something there. Reread my graph and I may be wrong at 530 peak, more like 505, but the label says Nm. I read another post about
a pinto that had much lower figures to.
Could it be something to do with "at the wheels" ?
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dinosaurjuice
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| posted on 14/3/09 at 08:22 PM |
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430nm at 6000rpm is about 350 hp
its definately measured at wheels...
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Blairm
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| posted on 14/3/09 at 08:42 PM |
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350HP, I'll take that
This companies bread and butter is tunning Chev LS1 and LS2. Maybe my crosslfow is to powerfull for it LOL
As an aside he had a brand new 6.0 litre Chev sitting there and the tape measure suggested it would fit with a dry sump. Any one keen?
Anyway, looks like his machine is very screwy. Hope the HP is also not 3 time over estimated!!!
Sheet attached for your interest.
Any comments on Cam choice and 1300 pisotns anyone?
 
Rescued attachment Dyno Sheet.JPG
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turboben
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| posted on 14/3/09 at 10:04 PM |
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Just guessing but maybe the torque figures are at the wheels after the gears have increased the torque. If you knew what gear was used you could work
out a rough flywheel torque figure with a calculator.
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clairetoo
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| posted on 14/3/09 at 10:05 PM |
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My thoughts.......a wilder cam would help at higher revs ( I prefer the 244 ) , and the biggest valves you can find ( 1 5/8 inlet , 1 3/8 exhaust work
well )
A compression hike will help - go for the 1300 pistons , but be sure to deepen the valve pockets  )
That sort of setup will happily rev to 8000 - my horsepower was still climbing when the rev-limiter cut in at 8 )
Are you allowed fuel injection in the class you run ? If so , go for throttle bodies and dump the distributor and it will still be drivable and
economical .
[Edited on 14/3/09 by clairetoo]
Its cuz I is blond , innit
Claire xx
Will weld for food......
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Blairm
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| posted on 14/3/09 at 11:01 PM |
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Thanks Claireetoo,
At moment can run anything in sprints. It is not limited, but I plan to run classics and need to stay standardish. Otherwise I would og Toyota 4age
or may Nissan SR20.
I would love to through the webbers as they are so expensive to get set up and running our of people who still familiar with the art.
Thanks Blair
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clairetoo
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| posted on 14/3/09 at 11:13 PM |
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So............how about a megajolt , with the coilpack where the distributor used to live ( so the plug leads will still appear to come from a
dizzy...)
That will improve both torque and high RPM power.....
Its cuz I is blond , innit
Claire xx
Will weld for food......
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Blairm
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| posted on 14/3/09 at 11:20 PM |
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I think Electronic iginition is OK, but they expect it to still have a distributor. Do you have a photo of this set up.
Never seen a MegaJolt in New Zealand. Not common over here.?
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thunderace
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| posted on 14/3/09 at 11:30 PM |
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twin 45's with 36mm chokes.
twin 40s for a xflow 1600-1700 with 34 chokes max .
you should be geting around 135bhp with 1300cc pistons fitted and big 34mm and 41.3mm valves.and a 234 cam
 
 
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clairetoo
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| posted on 14/3/09 at 11:39 PM |
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WOW That supercharger setup looks awesome - although there may be a slight bonnet clearance issue
Its cuz I is blond , innit
Claire xx
Will weld for food......
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Blairm
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| posted on 15/3/09 at 12:26 AM |
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Bonnet clearance as well as visability issues!!!
How well did the supercharger go?
Not a lot of room between the valve seats in that photo.
Ive got 39.2mm inlets and 33.7mm exhausts at the present and there is a little meat left between them, so some room to improve. Looks like from the
photo it will be more likely to crack though? Your experince?
So if good valves, 234 cam and 1300 pistons will give you 135, a 244 will be a little better again I guess
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clairetoo
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| posted on 15/3/09 at 12:36 AM |
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I've had a few cracks in heads - both between the valves and fron valve seats to plug threads
TBO not really a problem - they crack , you re-cut the seat - and the crack gets no bigger and causes no real problems (IMHO).
The 244 is a great cam - really lets it rev
Its cuz I is blond , innit
Claire xx
Will weld for food......
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