As promised, I have some before and after dyno results with various modifications to a 97 I6 XH 5spd ute (128000k).
The first dyno run I made was a few months ago and unfortunately I'd already fitted an exhaust system, so I don't know how much power it had when completely standard.
Anyway, it's peak power was 122kw at that point.
From some other reports I've seen, the standard car produced 118kw.
4kw from an exhaust sounds feasible and although it didn't feel heaps more powerful, it was a little more willing to rev.
The next modification was a the fitment of the broadband manifold, this made quite a difference to the bottom end performance, but made no noticeable difference up top.
The dyno proved this assumption showing around 15kw increase from around 2800rpm to 3600rpm. The top end actually dropped very slightly down to around 119kw.
Step 3 came the JMM extractors, plugs and leads.
The engine felt very lively after these went on, revving out to redline much easier and not feeling so restricted. Power seemed to be improved right across the range.
Again the dyno proved this with a 3-5kw increase from the moment the throttle was opened. Peak power was back up to around 123kw.
Step 4 came the JMM DEV3HL cam, valve springs and vernier gear.
Wow, this made a huge difference, the engine now loves to rev all the way to the cut-out of 5700rpm.
Power seems much the same at low revs, though a little stronger at the manifold changeover point (3800rpm), but above 4500rpm is where it really takes off.
The dyno again, re-inforced what I felt, with an improvement of around 7kw between 3500-4200rpm (no improvement below this though), and a 15kw improvement above 4500rpm to peak at 138kw.
An excellent result I think. JMM claim 150kw from this package which has now been followed to the letter, though taking into account dyno differences and engine age (128000k), I can comfortably say that the DEV3 HL package lives up to it's claims.
I did speak to Jim from JMM about the results, and he suggested that I could advance the ignition timing a little further and possibly get a little more out of it. I haven't had a chance to do this as yet, and I don't really want to spend another $40 to play around with ignition timing, but I will report back with seat of the pants feel, if it appears to make any difference.
Well I can definately give the thumbs up to what soxx has done with the JMM gear...
From what it was before the JMM gear and Manifold change to now, WoW, what a huge difference...
Revs up very quickly and gear changes cant come fast enough....Overall a very nice package that will keep a smile on your dial.
I Highly recommend it !
MMMM, i like these figures Soxx, i noticed a difference when i got rid of my Genies and put the JMM headers on.
Now i've just got to get my money for my cam/Springs/cam gear, i have a good base of 135 rw atm.
So it should get me where i want to be.
I am after 161rwkw, before i put in a Unichip.
The next modification was a the fitment of the broadband manifold, this made quite a difference to the bottom end performance, but made no noticeable difference up top..
LOL, whats next? Dialup extractors?
20kw gain!! what did all this cost you? $500? $1000? I think any more and you did you dough bigtime.
Car's I have owned. First car purchased in July 1994, in order of ownership.
VC Valiant 245Hemi, 280zx Nissan 5 speed, 88 EA 3.9CFI,94 ED Gli X Chaser, 79 FC LTD, 351, FMX, 91 EA2 Fairmont Ghia, 1999 AU S pack, 2000 AU Forte, 1992 EB2 XR8, 2001 AU2 SR, 2002 VX2 Acclaim, 2002 VX2 Manual S pack,2003 BA XR6 manual, 2001 VX2 Berlina.
Without wanting to appear offensive, I have to agree - 20 rwkw does seem a little low for the kind of work you have done. 150 as claimed would have made it 30-odd kw; a little more reasonable I feel for the money involved.
Perhaps the dyno you used was out of tune: another run on a different dyno might be in order.
But hey, glad to hear you're happy with it!
Proud TQE Operator and President of SEFAG - the Society for the Elimination of Ford Automatic Gearboxes
Pacemaker headers + 2.5" exhaust
EF Fairmont interior
Lowered King springs
5 speed manual
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