HAHA I ment 0-60 times with new MODS

[smokey]

I would like to give my experience with a few mods to my 1988 Comanchewith AW4.

 

1988 Long bed with 31 bfgs and 4.10 gears weight at truck scales of 4,300lbs.  About 150K on the stock motor(k&N filter).

After a tune up (plugs and wires and dist) I did 10  0-60 runs using nickintime engine monitor.

Best run was 13.28s at 5,000 feet 65f. Using a HP calculator that's about 118 hp at the wheels.

 

Not to bad at 5,000ft and about 500lbs over stock. Stock time would be 10.9s or about 140 hp at wheels.(Published by 4 wheel drive mag in 1988 : ))

 

SO, the fun part the mods. $75 ebay

First 1990 auto engine ECU.  NO change.  Well maybe a little worse the best 0-60 time was 13.31 (maybe could be driver error?)

Where is the 7 hp everyone says you get with the ecu swap????  I do think it shifts a little different but that should be controlled by the TCU so if anyone knows if the newer ecu really does anything different I would like to know.  I also noticed no change in A/F ratios or duycycle of the injectors at 5,000 rpm.

 

Second mod. $135 Jeff Liegh

62MM throttle body. BOOM 2 HP gain.  Best time of 10 runs was 13.22s.

My old throttle body was is rough shape.  Also the grommet with the MAP hose was pretty bad too.

New throttle body and MAP grommet did help a lot with the idle too.

 

Third mod. $62 Amazon

Volvo 746 injectors. BOOMMMM 5 HP gain .  Best time of 10 runs 12.77s

 

WOW my old injectors were crap 4 where org and 2 had different nozzles on them.

 

So for $272 I got 7 real world HP gain.  I am going to drive it for a couple of weeks to see if the ECU learns anything and do some more runs.

I will post up if I see any other improvements like cold starts or mpg (I think it will go down because I will be hammering it all the time, I got 16mpg avg on 10 fillups before)

 

I also wonder if I did the injectors first would that of change the other mods?

[Pete M]

science can be a blast  

 

what happens if you swap back to the old ECU?

[smokey]

Good call.  I will try that. First I am gonna run the new ECU for a week and do some more runs and see if there are any changes.  I will then swap back to the factory and post the results.

 

 

[eaglescout526]

I think you need the Mopar Performance ECU from 1990. Course sourcing those will be next to near impossible.

[WahooSteeler]

746 injectors are hands down the best bang for the buck for overall performance gain IMO. Glad to know they likely add HP but just from the substantially increased responsiveness and smoother idle, I'd pay double or triple the $60 I paid if I knew what a difference they would make. The value ratio of improvement vs cost is off the charts. 

[Pete M]

yes, I kinda figured you meant 0-60   

[smokey]

Ok, finally got around to swapping ECU back to Org 1988.

Almost no difference in 0-60 times.  So I don't think there is any topend realworld hp diff in the 1989-90 ecus.

Most of my gain was the injectors. (best mod for the money).

Now that I have stop drag racing it, I will run a tank a gas through and see mpg changes.

 

But, two things I have noticed are better 25-50 mph run times and one of the things I think is weird is way cooler engine temps.

On the two different sensors (bottom and top of engine) I am seeing 20-25 degrees cooler temps on warmup.

 

With the 1988 ecu I see 210 warm

and with the 1990 ecu I see 185 warm

 

I wonder if the calibration for the sensors is different for the different model years ecu?  I think the Nickintime cpu reads the raw data not the ecu data but I don't know.

 

I do know the heater does not blow as hot with the 1990 ecu, so I would think the engine is running cooler.   Maybe not as lean.

 

Keith

[Pete M]

those temps... are weird. 

[MiNi Beast]

running more effeciant means better cooling engine temp wise.