Dr Dyno Map Adjuster Dyno test 1997 XJ

OmarTurbo

NAXJA Forum User
Location
Puerto Rico
Hi from Puerto Rico, sorry for my english im not good.

Im take the task to build a Dr Dino Map Adjuster for my 1997 Cherokee and these my results in the Dyno



Ignore the peak does because transmission changed 3rd gear, we take 2nd gear run, nothing badly 10whp and 10wtq for a 100,000miles engine with a little blowby with a Dr Dino Map Sensor Adjuster, in fact I did not more runs but because the filter did not help me since take hot air from radiator that Jeeps in fact runs Rich in AF Ratio as they can see it happens of the 115.53whp run is my XJ it without the MAP Adjuster low until 10.6 afr after the adjust the MAP to 4.8v we managed that in crusing it ran in 14.5 to 14.7 afr and WOT in 11.4 with the final result of 125.82 whp 10.34whp and 10.68wtq not bad of difference with a modification that does not exceed $30bucks!
 
You should see if power changes going 12.5:1@WOT. If no change, at least you trimmed some fuel back.
 
final result of 125.82 whp 10.34whp and 10.68wtq not bad of difference with a modification that does not exceed $30bucks!

Glad you're happy with the results from such a cheap mod. Before you try leaning the AFR further I suggest you do two other things. Firstly, build a heatshield around the air filter to isolate it from the hot underhood compartment. Secondly, remove the crankcase ventilation grommets from the valve cover and clean them thoroughly. Blow some compressed air through them to clear any dirt. Also make sure that the inside of the plastic pipe going from the rear grommet to the intake manifold is clear. This might help the blowby problem and improve the engine's performance.
 
Thanks for sharing! That is a nice improvement, but I do worry about how rich it runs in the top end.

I imagine that was a noticeable improvement when you started driving.
 
Im really surprised because there are modifications that are worth much more and they do not give that horsepower and the difference feels from idle, before the mod the idle it feels rough and now feels smooth including the acceleration!
 
I'd be interested in seeing what happens if you get closer to 12.5-12.7:1

it can be that it increases more like 7whp+, comparing with the gain that it just by obtained to take AFR to 11.4, but there are several factors that do not help me like filter taking hot air from radiator and cracked exhaust manifold!
 
I think about knock? (alot) Do the 97s have a Knock censer?
If not and you running a loud muffler be careful about ping as you lean it out.
 
Only Renix 1987 to 1990 had knock sensors.
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Thanks
I don't know how you took you A/F readings but most just replace the O2 with a wide band. That will give a nice average A/F.
Problem: Even with PFI some cylinders may still run a bit lean. Fine with a fat A/f of 10.XX at WOT. Even a lean cylinders will get plenty of fuel.
Now lean that average to the edge and ping MAY set in.
How to check with loud muffler: Go old school. Keep an eye on your plugs.
FIX: Clean/replace injector will generally do it in an other wise sound engine

Yes timing is important. But he made no post of changing timing and the factory curve is a very safe one if not to safe. But the factory has to think about NOs emis. So timing would be a bit slow. IMO anyway.
 
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