1992 Dodge Dakota 5.2 Magnum advice

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MagnumDakota

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Hey everyone. Im looking for some advice on what to do with my 1992 Dodge Dakota with a 5.2 Mag. Its a regular cab short bed with a 3.92 suregrip rear and a auto o/d tranny. Im actually shocked at how quick this truck is for being stock! I had a new 1999 Dakota RT 5.9 and this truck is alot faster! Im guessing the weight difference? Anyway what would be some good mods to do to this motor? Should I get the Mopar Performance ECU? Bigger throttle body? Different intake or work the stock one over? I plan on putting a 180 degree thermostat in it next weekend and I am also having the exhaust done. No cat and a performance muffler at this time, in the future I will be running true dual exhaust. Going to run the stock manifolds seems how they are the 92's. Would I gain any more power if I was just to convert it over to carb? Or should I keep the efi setup? My goal is to get into the 13's eventually. Thanks for any suggestions!
 
That truck was faster than the 5.0 Rustang and 350 Fireturd when it came out. I have a '93 myself, and it's run with late models.

Best bang for your buck is the magnum bolt on centrifugal supercharger kits.
 
Welcome aboard!

Contact @magnummopar

What does the truck weigh?
Go to Summitracing.com and enter in the search bars your information and it will slit back some answers for you on parts and price.

Adding a super charger is an excellent idea. Adding regular go fast parts on top will also be a bennifit to power production. You will need the computer to be reflashed.
 
The first thing is to free up the exhaust.
Any other mod you do, will be choked by a single exhaust and the logs. Say you spend $300 on an installed cam, and move the power up 400 rpm which should make say 30 horsepower. But the logs and single exhaust choke half of them. Kindof a waste of time and money,right? If all 30 hp were available, your engine might feel 30/230 = plus 13% bigger..............at peak-power RPM say 5000, while giving up some off-the-line grunt. But if only half of them survive the exhaust system then it will only feel 15/230=plus 6.5% at peak-power.But I think I see a better solution;
You already have the 3.91s, that's great. But if you have a 727, the starter gear is 2.45 x 3.91 =9.58.Which with typical truck tires of 225/75-15 (28.3 tall), could be better. This combo will get you 42mph @5000 at the top of first gear, which is pretty good. But,that O/D will get you 65= 2100. So there is room for a bit more TM,Torque Multiplication. For example; 4.30s would cruise at 2300, yet the starter gear would be 4.3 x 2.45= 10.54. This would really launch the truck if you could make it stick. Top of first would now be 38mph, but more importantly, top of second would be revved out at 5000=64mph. And even more important, the downshift into first at 30 mph would be about 3950. The extra TM of the 4.30s will make your engine feel like it just grew by 4.30/3.91= plus 10%. And it will feel like that in every gear, and at all rpms. The only other mod to your 318 that will do this is supercharging. (or stroking,I guess,lol). And gears are cheap. And you can keep your single exhaust a little longer.
If you only need a little more oomph off the line, then a higher stall TC is the most logical solution. This will allow the engine to wind up several hundred rpm higher, to where more power is available. This will really wake up the combo. You'll need a traction aid of some kind.

Now if you combined both of those; a higher stall TC and gears, well, that is the most bang for the bucks spent.
 
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Can I get the old computer reflashed? Or is the Mopar Performance just a direct bolt on? The super charger would probably be out of my price range.
 
I always had heard that the 92/93 magnum manifolds were some of the best flowing exhaust manifolds out there. Not as good as headers but flow good. Thanks for the tips!! Never thought about going to a lower gear.
 
Lower gear is more torque release but high rpm's and reduced top end.
The exhaust manifolds can be OK but the actual units you have I am unsure of. There is a set of big 2-1/4 (IIRC) exhaust outlet manifolds.

You would need ether to be flashed with a super charger and the MP computer is only good for the mods they speced.
 
MagnumDakota said:
I always had heard that the 92/93 magnum manifolds were some of the best flowing exhaust manifolds out there. Not as good as headers but flow good. Thanks for the tips!! Never thought about going to a lower gear.
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I tell you whut, every streeter I ever installed a rear gear for, absolutely loved it. You cannot imagine what 4.30s will feel like; you will not be able to stop smiling.
And the first time I ever swapped out the stock TC behind my teener for a 2800TC, I couldn't stop smiling for a long time. The old LAs really woke up with 4.30s. Your Magnum might do well with 4.11s, but that is only a step up from 3.91s so really not that big of an impact. And with the .69 overdrive, 4.30s would be my choice with a stock TC.
If you go TC first, then you'll have a better idea of what gears you might want, which is the way I'd go.
But before I would do anything, I would do a stall-test on the one that is in there. If it flashes to 2800,say, then it would be difficult to justify a bigger one for the street. But if it flashes to only 2000 or less, then it's a no-brainer for me.
But with a TC you are gonna have traction issues. So then you'd have to fix that before moving forward.
 
AJ, my memory fails, what's the OD ratio of the A-500? Which he more than likely has in a Dakota truck. .68?

Magnumdakota, multiple the OD ratio by the rear gear ratio for the final drive feel.

4.30 X .68 = 2.92. Still a very friendly street and Hwy. gear.
 
MagnumDakota said:
I always had heard that the 92/93 magnum manifolds were some of the best flowing exhaust manifolds out there. Not as good as headers but flow good. Thanks for the tips!! Never thought about going to a lower gear.
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You are correct, and not just the exhaust manifolds, but the Y-pipe as well. Also, the cam has a little more duration as well.
  • I believe there was an MP performance computer available
 
Intake is #1, the exhaust system has a ton of back pressure.
Any intake would be a huge improvement & your normal calibration should work pretty good, it's very conservative.
After that a bit higher compression & I think 2.02" intake valves fit.
The heads have a lot of flow but the engine RPM is limited by valve train stiffness so it gets harder to take advantage of the flow potential.
 
What does the truck run in the 1/4 now? Sticky tires, good converter, good chassis setup, good driver, and dual exhaust may be all you need for 13s.
 
SSVDP said:
Intake is #1, the exhaust system has a ton of back pressure.
Any intake would be a huge improvement & your normal calibration should work pretty good, it's very conservative.
After that a bit higher compression & I think 2.02" intake valves fit.
The heads have a lot of flow but the engine RPM is limited by valve train stiffness so it gets harder to take advantage of the flow potential.
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I disagree!

Exhaust #1!!!!
Intake is sufficient for reasonable sizes camshafts. Internal mods support over 450hp on the stock legged intake.

Only an arrow number of camshafts will allow a stock calibration.

I'd go 1/2 a point more unless a reasonably large street camshaft is used. 9.0-1 is supposed to be the stock ratio and it is enough with the proper camshaft to make a lot of hp.

Not that a 2.02 valve wouldn't help but it now, in my eyes, wonder if a few minor hp extra would be worth the otherwise comparatively huge expense of adding said valves.

What the hell is valve train stiffness? That would limiting?
I have NEVER heard of that!!!!
 
rumblefish360 said:
AJ, my memory fails, what's the OD ratio of the A-500? Which he more than likely has in a Dakota truck. .68?

Magnumdakota, multiple the OD ratio by the rear gear ratio for the final drive feel.

4.30 X .68 = 2.92. Still a very friendly street and Hwy. gear.
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You know it!

And with 235/75-15s being about 29 tall, they correct the 3.91s to 3.91x 24/29= 3.24s with 24s . Now very few people run 24s. Typically we run something like 25.5s, which would correct 3.55s(also typical) to 3.55 x 24/25.5=3.34s. So 3.34-corrected is a typical target when an O/D is not available.
Now as to OPs combo, compare those 29s and with 4.30s; 4.30x 24/29= 3.56s.
Another option for the OP is much smaller tires, say 275/50-15s which are 25.8s, which correct to 3.91x 24/25.8=3.64s. Which compares very favorably to the 4.30 x 29s @ 3.56. Of course the front tires would also have to be changed. And then there's the rather odd appearance of a Dak on small tires........ but hey, if you can borrow a pair of 24s or 25s for a test run......let the fun begin!

My son had an 84 D100. I put my winter-motor, a stock 1973 318 into it with the TQ on it and stock exhaust. And we put 3.55s into it, a 2800TC and an A998 with the 2.74 low gear in it. Then we put my used 275/50-15s on it. That truck had a whole new personality. The starter was 2.74 x3.55=9.73 and corrected to 24s this is a 9.05 starter.( This compares to 9.05/2.45= 3.69s with a 2.45 low, and would require 4.46s in the Dak with 29s to compare). I had to fab a traction aider cuz with the 2800, and the TQ set on stun, those 275s just couldn't take it.Top of first was about 40 mph.
The OPs Dak with a 4.30 x2.45low and 29s corrects to 8.73; within 4% of our D100 with it's 9.05 corrected starter. Now add in the 2800TC, and let the tire shredding begin.
And remember, that 318 was totally 1973 low-C vintage, except for the TQ, and it was breathing thru the 1984 logs and Y-pipe,lol.
 
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Thought I would update this... And Im seeking some more advice. I no longer have the 92 Dakota. I have a 93 Dakota now with a 5.2 and the a518 tranny and a 8.25 rear with 3.55 gears and a suregrip. This truck has a lot better body and is in much better shape overall. The 92 was faster alot off the line but it had 3.90 gears.
Here are a few of my questions. Would you guys run a 4.10's or 4.56's gears? Im going with what AJ said and the lower gears will defiantly help! I would like 4.30's but they dont seem to make them for the 8.25. I currently have 255/60/R15 tires. And the od tranny. The truck would see some highway use but not much. Mostly around town etc... So im leaning toward the 4.56's

As far as the motor goes its basically a stock 5.2 magnum. Does have the Mopar Performance computer. Now I can pick up a running 5.9 cheap. Was thinking of putting that in the truck and converting it to carb... Run a Airgap intake and and electronic ignition and a voltage regulator and keeping the serpentine belt set up so everything I have would bolt up etc... Now how hard would it be to get a fuel pressure regulator set up in this? Would be running the stock in take fuel pump. Also what about the linkage and throttle- kickdown for the tranny going from efi to carb? I know I will have to take care of the tranny for the lock up to work and od. Researched that on here.

Another option is I can take the 5.9 and run the Hughes air gap f.i setup and basically just use everything I have. But my big concern with that is would I make the same amount of power vs the carb route? I may but a cam in the 5.9 and a install a reconditioned set of heads and springs for the cam. Nothing fancy just basic. Anybody have any experience with that Hughes airgap f.i manifold? Its basically all thats out there if I stay efi. Changing the gears and dual exhaust and with the 5.9 the truck should be alot quicker than with the 5.2. Just not sure whether to go carb or go with the hughes setup.
 
MagnumDakota said:
Thought I would update this... And Im seeking some more advice. I no longer have the 92 Dakota. I have a 93 Dakota now with a 5.2 and the a518 tranny and a 8.25 rear with 3.55 gears and a suregrip. This truck has a lot better body and is in much better shape overall. The 92 was faster alot off the line but it had 3.90 gears.
Here are a few of my questions. Would you guys run a 4.10's or 4.56's gears? Im going with what AJ said and the lower gears will defiantly help! I would like 4.30's but they dont seem to make them for the 8.25. I currently have 255/60/R15 tires. And the od tranny. The truck would see some highway use but not much. Mostly around town etc... So im leaning toward the 4.56's

As far as the motor goes its basically a stock 5.2 magnum. Does have the Mopar Performance computer. Now I can pick up a running 5.9 cheap. Was thinking of putting that in the truck and converting it to carb... Run a Airgap intake and and electronic ignition and a voltage regulator and keeping the serpentine belt set up so everything I have would bolt up etc... Now how hard would it be to get a fuel pressure regulator set up in this? Would be running the stock in take fuel pump. Also what about the linkage and throttle- kickdown for the tranny going from efi to carb? I know I will have to take care of the tranny for the lock up to work and od. Researched that on here.

Another option is I can take the 5.9 and run the Hughes air gap f.i setup and basically just use everything I have. But my big concern with that is would I make the same amount of power vs the carb route? I may but a cam in the 5.9 and a install a reconditioned set of heads and springs for the cam. Nothing fancy just basic. Anybody have any experience with that Hughes airgap f.i manifold? Its basically all thats out there if I stay efi. Changing the gears and dual exhaust and with the 5.9 the truck should be alot quicker than with the 5.2. Just not sure whether to go carb or go with the hughes setup.
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Before throwing the towel in on the EFI contact Ryan Hogan at FRP Tuning. I'm running Hughes air gap, Vortech V1 T-trim, 58mm F&B throttle body and Ryans tune on a 5.9/408 in a 03 Dodge Ram.
If you have a Facebook account you can talk with other guys at FRP FACEBOOK You'll have to join the group. I'm a member there.
 
I'm considering running though Hughes intake. But I have a OBD1 so I'm limited it what can b done from my research. That could b wrong though. Most of the tunes are for OBD2. I can get a 94 Mopar Performance 5.9 ecu which would work on the swap. And I don't want 2 switch it over 2 the OBD2. So I just want to know what make the most power say on just a stock 5.9. The Hughes air gap f.i. or a carb and a air gap? If I go with a carb then I will have 2 deal with the fuel pressure etc.... the gears should defiantly help. Thanks for the reply... I have read where some people switch the over 2 the obd2 setup and it works good. I just don't want 2 do that at this point
 
92 is the best year for Magnum exhaust.

IIRC the 5.2 for that year was only rated 10 less HP than the 5.9- 235 vs 245.
 
MagnumDakota said:
I'm considering running though Hughes intake. But I have a OBD1 so I'm limited it what can b done from my research. That could b wrong though. Most of the tunes are for OBD2. I can get a 94 Mopar Performance 5.9 ecu which would work on the swap. And I don't want 2 switch it over 2 the OBD2. So I just want to know what make the most power say on just a stock 5.9. The Hughes air gap f.i. or a carb and a air gap? If I go with a carb then I will have 2 deal with the fuel pressure etc.... the gears should defiantly help. Thanks for the reply... I have read where some people switch the over 2 the obd2 setup and it works good. I just don't want 2 do that at this point
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Also check out this guy's website:UTAWESOME PERFORMANCE - Home
 
MagnumDakota said:
I'm considering running though Hughes intake. But I have a OBD1 so I'm limited it what can b done from my research. That could b wrong though. Most of the tunes are for OBD2. I can get a 94 Mopar Performance 5.9 ecu which would work on the swap. And I don't want 2 switch it over 2 the OBD2. So I just want to know what make the most power say on just a stock 5.9. The Hughes air gap f.i. or a carb and a air gap? If I go with a carb then I will have 2 deal with the fuel pressure etc.... the gears should defiantly help. Thanks for the reply... I have read where some people switch the over 2 the obd2 setup and it works good. I just don't want 2 do that at this point
Click to expand...

Oh.... yeah... OBD1 sucks. Thought you had OBD2. Some guys on the facebook forum have switched out he OBD1 to OBD2 but don't know how involved it is for sure. Mostly switching out wiring at the ECU connectors and adding a few from my understanding. If it was me I would avoid carb with all cost. The truck is already set to run EFI with all the advantages of running EFI. Unless this going to be a drag truck or play truck rather than a daily driver. I'd switch to 5.9, do all the updates your speaking of to the engine, send the ECU off to someone to tune it .... I think that is a option running OBD1. I thinks it's B&G Chrysler or Tom Fox or something like that.

Can also go stand alone EFI like Holley Sniper, or FI Tech but don't know if it will run the transmission OD, and lockup.

If you're going to carb you can run any intake you want but I would definitely go air gap if it's just a mild build. I installed the Hughes air gap on my stock 5.9 with a tune but didn't "feel" any difference. There was some but not a whole lot.

I'm running 4.56 gears in my 9.25 rearend with a TrueTrac diff. I wanted to go 4.88 but Eaton highly recommended not to do so utilizing the TrueTrac and it would void the warranty.
Also consider a different torque converter from Edge. Go with a higher stall but still have street manners. This will get you out of the hole quicker for sure.
 
Your 255s are ~27 tall, so ~85" roll-out. For your combo;I would consider 4.10s, because;
The effective starter gear will be; 4.10x2.45x24/27=8.92, but the TC will kick in another ~5%, so,9.38. But the instantaneous ratio at zero mph could be as high as 15:1.. You will need a SureGrip
IIRC, The 5.2 power-peak is about 4700rpm, and you can stretch that, in first maybe to 5000, so;
At 30 mph,and at kickdown, the Rs will jump to ~3900 in first gear which will climb to 4800@37mph. Then at the shift the Rs will drop to ~2800 in second; so that's a bit of a hole to climb up out of.But second gear will get you 60@4650 at the top;very close to perfect . I suppose you could use 4.30s for max effort, but that will hurt the KD at 30mph.
And 4.10s will cruise 65=~2300 in loc-up.
If the take-off is too weak FOR YOU, at 9.38 effective TM, with EFI, and the factory TC, and a SureGrip; then a higher stall TC is next.
If you swap to a carb,you will lose a ton of low-rpm torque; Hughes Engines shows a loss of~50 ftlbs@2700 on a 5.9,when giving up that EFI BeerKeg intake. So on a 5.2 figure on a 40/45ftlb...... That is probably more than 10% loss..... So;budget a higher stall TC for sure; a 2800 will more than cover it..
Of course with a 2800TC, you wouldn't need the 4.10s anymore.............. But I still like them because it's the right gear to hit 60 mph with. And the 2800 will lay a lickin' on the tires, off the line; of that, I am sure. (Even with 3.55s the tires would scream.). And you have both a loc-up and an overdrive so it's no biggie to drive 4.10s.
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FWI
I had a 92 LWB extended cab Dak up to about 5 years ago. 5.2EFI/A518/4X4/ 235/75-15s on it and a 3.91 SureGrip. Great truck! Not a tire fryer, but a good amount of tirespin for sure; even with close to 300,000 miles on the clock. I miss it every now and then.That BeerKeg-intake really works.
 
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Thanks for the replies... AJ do i think 4.56 gears would b to much? Also if I stay with the fuel injection do u think I would see any gains with the Hughes f.i. air gap set up? Would it be worth it or just keep the the stock kegger? I think it would be worth it 2 drop the 5.9 in there? Pretty much a direct swap and I can keep the f.i. etc... Would also put a converter in there with the motor swap. Thanks again
 
But for the price of the f.i air gap, I could get a converter. So think I will just maybe run that beer keg for now.
 
IMO, AJ nailed that to the wall.
The Hughesengines FI-AG is a real nice I take but the gains you get from it in what you have are marginal at best really. I’m sure a dyno will show a magazine eye popping rise in power ( sarcasm! ) but your not going to really reap the Potential benefits until you start swapping out cams.
Your basically leaving 2500 upstairs rpm on the table.

The TQ converter will hand out the best bang for the buck and have a instant gratification feel to it. If you intend to swap out a cam later, while talking to the converter people, let them know what cam you intended to use.
 
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