3.0 V6 performance

[Murphy]

So, I'm looking at a car tomorrow that I am most likely going to buy. 1991 Plymouth Acclaim 3.0 V6 3 speed. This is going to be my new daily driver, but i want to do some bolt-on's to get some more performance out of it.

Planned so far:
52mm TB
CAI
Under drive pulley
1" Plenum Spacers
2.5" DP back exhaust with a hi po cat and super turbo muffler
Magnecor Plug Wires
NGK V-power plugs
180* thermostat
15* timing

Later/considering:
porting a plenum from the JY, or buying one if I see one for sale...
Hi Po cam(diamante or ???)

I am also considering a TB spacer for more plenum area and a hotter coil, but i dont know if they would really be worth it.

Since it is a 91, it will most likely have leaky valve guides, and I will want to fix that. while its apart, I'm thinking about getting the heads milled. Has anyone done this? how far can I go? Also, if i cant fine the diamante cam, what is a good aftermarket one?

[j4278h]

rip out that slush box a670 and drop a manual a543 in it.

that will be the best bang for the buck on these 3.0 and it will be more fun to drive.

[Frank]

UDP is a waste of money for the return. Magnecor is a waste... a good setup of regular wires and Champions.

[Murphy]

I'm considering a manual swap one day if the 670 starts going out. I know the UDP woln't gain me much,. but someone is selling one used here I am planning on buying. I might just stick with stock wires, or try making a custom set.

[93sundance]

crimp a set of accel wires

[Vigo]

the tb spacer is definitely a waste. The biggest thing you can do to affect plenum volume on the 3.0 is to grind out the divider in the middle of the plenum. that will effectively double the plenum volume that any given cylinder sees. No amount of TB spacer can do that. Plenum spacers have been proven to be minorly helpful, but dont pay too much for them. You might have to clearance your hood to run 1" ones.

be aware that actually fixing your heads or replacing them with reman'd ones plus gaskets and your time is going to end up costing as much as the car. just FYI. You'd be better off just buying heads off a newer motor that dont have that problem out of the junkyard. or a whole motor out of a 96-00 caravan. They have slightly higher compression to go with their fixed valve guides.

This is my personal opinion based on having replaced heads to fix valve guide issues on a 3.0. *For the money, it would be the same price and probably less difficult to swap the whole motor with one from a 96-00 van.*

Or just deal with the oil burning. Its a legitimate strategy!

The old nick boer's pulleys actually made a very nice difference but they were like 25% underdriven so it was a huge underdrive.

As far as i know there are no off-the-shelf sohc cams other than expensive RPW stuff. regrinds would be the only 'cheap' option if you want something better than diamante cams.


it'll be a decently quick car, even auto. I think josh got a stock 670/3spd spirit to do 16.1 or something, and we know that 3.0s gain a good bit from minor mods. multiple people have run 14s n/a with bolt-on 5spd 3.0 spirits.

[inmyshadow]

your mods list on a 5spd would be around 150whp.

my daytona put down 153whp with 52mm tb,dynomax cat back,cai, and fm underdrive.

later on I made 158whp with ignition piggyback computer after dyno tuning. I wouldn't waste time on increasing timing only three degrees. there is no power gain. I had advance timing by up to 15 degrees over baseline. even then, it only helped on the topend.

don't waste money on aftermarket coil or full exhaust. as for cutting out center divider, nobody have shown any proof it works. my concern is that some cylinders will lean out. chrysler thought the divider was important to use it.

i do agree with going with later 3.0 over rebuit heads. that with a mitsu individual runner manifold should make some sweet low end torque

in the end, my daytona also had a lightened flywheel and 58mm tb. people thought I was crazy autocrossing . the motor revved like a motorcycle. the motor was so snappy i could save the car from the most dire spins. plus I'd bounce off rev limiter alot to save a shift.





Planned so far:
52mm TB
CAI
Under drive pulley
1" Plenum Spacers
2.5" DP back exhaust with a hi po cat and super turbo muffler
Magnecor Plug Wires
NGK V-power plugs
180* thermostat
15* timing

Later/considering:
porting a plenum from the JY, or buying one if I see one for sale...
Hi Po cam(diamante or ???)

I am also considering a TB spacer for more plenum area and a hotter coil, but i dont know if they would really be worth it.

Since it is a 91, it will most likely have leaky valve guides, and I will want to fix that. while its apart, I'm thinking about getting the heads milled. Has anyone done this? how far can I go? Also, if i cant fine the diamante cam, what is a good aftermarket one?

[Dodge Aries K]

Umm... later 3.0's still burn oil.

http://s37.photobucket.com/albums/e92/teamaenoy/Aenoy%20Motors%20Official%20VAN/?action=view&current=DSCF1969.flv

Also, being a 91 it will have 604. The 3 speed was a 92-95 optional piece of equipment.

[j4278h]

what about all the 3speed v6 caravans from 87-91? or was that just for the vans?

[Dodge Aries K]

I'm referring specifically to the AA sedan. The vans got it from 87-00 with the 3.0. 88 New Yorker and Dynasty also were equipped with the 3 speed. Anything else was always 604 with 3.0, not counting the P/J/G bodies with 3.0 and 5 spd.

[Murphy]

the guy said it was a 3 speed.....I duno, i'll see when i check it out tomorrow

[93sundance]

it'll be a decently quick car, even auto. I think josh got a stock 670/3spd spirit to do 16.1 or something, and we know that 3.0s gain a good bit from minor mods. multiple people have run 14s n/a with bolt-on 5spd 3.0 spirits.

Well it had a 52mm TB. Other than that it was stock. It ran 16.1 @ 84.7. Driver weight was 235 lbs at that time. I forgot what my race weight was.

[Murphy]

it was a 4 speed........

I'll grab it next week if nothing else pops up

[Dodge Aries K]

604? Aww man... that's no fun.

If ya weren't from Maryland I'd get ya a good deal on a Neon or Cirrus :-p

[93sundance]

it was a 4 speed........

I'll grab it next week if nothing else pops up
Oh well. Drive it till the trans dies then do the 5 speed swaparoo :evil:

[Vigo]

604 is kinda neato if you wanna take it out and swap some parts.

you can gear it down a lot and use a stock neon converter on a different stock flexplate to get a higher stall and 4.10 diff ratio compared to stock 3.6. flexplates are cheap in the yard, converter costs about $70 if you can get someone to hook you up or use a used one, and the other gears you can probly get for 100 something bucks from a used trans parts place.

brent (ondonti) ran 15.4 in his 3.0/604 spirit (without any trans mods) and hes not the only one to run around there with a 3.0/604 spirit. of course it ran 14s 5spd. 13s w/turbo on low boost.. and his other turbo 3.0 is trapping in the 110s mph in a very unsorted state. There's a lot of potential in there.

[Murphy]

well i got my tona to run again so i might not even b getting another car....plus i have a plan for my old spirit......

[93sundance]

you will change your mind after you break it again tomorrow...

[Murphy]

you mean your not soposed to do 30 psi for the break in? a 3 mile long burnout isnt a sufficent break in period?

[turbovanman]

Aurora wires, stock type replacements and Accel are junk. Run some Iridiums, 2.5 inch cat back.

UDP isn't a bad idea, I noticed a diff on my van using one.

Getting the valve seals isn't a big deal, just rip off heads and have a machine up install the updated guides, valve grind, problem solved.

I also sell some nice cams, an RV type grind and race cams.

Do the shift mods, make it shift nice and snappy.

[Vigo]

just rip off heads and have a machine up install the updated guides, valve grind, problem solved.

realistically you're talking like 4-500$ in parts and labor at least. add that to the price of the car in the first place and i'd bet you'd have enough to just get a better car. Not that its a bad idea. But i would DEFINITELY rather grab heads off a 96-00 van for something like $40 a piece or whatever from the junkyard.

[RoadWarrior222]

Everyone likes to blame the "legendary" dropped guides for smoking in these motors, but although it can happen, I think in many motors the seals are more the culprit, the Chryco ones don't seem to last long even in the newer motors, I've seen "mosquito fogger" 3rd gen vans out there.

What will make smoking MUCH worse is lack of attention to the PCV system, the internals of the PCV valves rot or clog, you get pressure buildup in the front valve cover at idle, and oil goes hosing down the guides past weak seals... Also the PCV hoses collapse either flat or swell and clog internally.

So two things to keep it clean, replace PCV valve and hose, and run HIGH MILEAGE castrol or pennzoil* 10W30. These have seal conditioners in and will cut smoking and oil consumption right back. If it's using a lot of oil at the moment, it will use a quart of those oils in the first week or two until it clears up, as it would use a quart or more of any other oil you put in it, after that with regular changes, it will likely only go from full to add on a 3-4000 mile change. Don't use oil additives with those.


(*yes there's other high mileage oils, trust me, don't use them, they are either overharsh on the detergents, making it smoke and leak worse, or too thin and make the motor sound like a bag of nails, those two work in the 3.0)

Ignition coils. Many people don't seem to realise that the chrysler coils are a fairly "hot" item to begin with, so improvements from anything else is pretty marginal. Best known mods seem to be to mount stock coil to a fabbed bracket on the plenum, or use a ford "5.0" coil from a mid 90s 'stang, cougar, or crown vic and mount it similar.

Rotor arm, get a smooth edged one, the sawtoothed ones are craptacular.

Plugs, champion double copper. Nothing fancy works very good, avoid bosch anything like the plague.

Fuel filter, change it now, change it yearly.

Plenum spacers, I have heard that 3/4 is maximum recommended on P body due to hood clearance.

Exhaust: check you have a 2.5" rear manifold/downpipe 'coz the 2.25 ones will make going bigger pointless. (Forgot when they changed) my van REALLY likes it's Walker SoundFX muffler... they're fairly cheap too.

O2 sensor: check it's not blowing, get an NTK/NGK/nippon denso or mopar one.

[turbovanman]

Everyone likes to blame the "legendary" dropped guides for smoking in these motors, but although it can happen, I think in many motors the seals are more the culprit, the Chryco ones don't seem to last long even in the newer motors, I've seen "mosquito fogger" 3rd gen vans out there.




Trouble is, that IS the issue, the guides drop, oil leaks, you get the blue fog. In the too many years I've been doing this, I think I've only seen this caused by bad seals. Funny how Mopar came out with a snap ring for the valve guide, :o ;)

[RoadWarrior222]

3 years are really bad for it, 87, 88, 89 some minor fixes went in and it got less common on 90, then the clips went in in 91.5 I think.... but still see a smoking '93 and people say "oh, dropped guides."

[Murphy]

just bought a 95 spirit 3.0 v6 3 speed auto, i'm picking it up tomorrow!

[Ondonti]

Ed actually has dyno proof on an accelerometer of the UDP.
It makes a big difference in the lower rpms but only a little whp at 5000+.
So fuel economy from stoplights!

[Murphy]

i went to install my 52mm TB and it doesn't have provisions for the transmission kickdown rod. can I only get the TB from a 87-89 3.0 with a 3 speed?

[93sundance]

i went to install my 52mm TB and it doesn't have provisions for the transmission kickdown rod. can I only get the TB from a 87-89 3.0 with a 3 speed?

correct

[turbovanman]

i went to install my 52mm TB and it doesn't have provisions for the transmission kickdown rod. can I only get the TB from a 87-89 3.0 with a 3 speed?

Or get the arm off a 46mm 2.2/2.5.

[93sundance]

Or get the arm off a 46mm 2.2/2.5.

I thought about that before, but I don't understand how to swap them.

[RoadWarrior222]

Doesn't everything transplant from the 48mm TB that was on there?

[Murphy]

ya how would I swap the arm? pull apart the whole part across from where the throttle cables hook up to the throttle position sensor?

[JDAWG]

well what size does my minivan have? 90 3.0 4spd.

[93sundance]

well what size does my minivan have? 90 3.0 4spd.

It should have a 46mm

[JDAWG]

so its ghey? What should I get? What about a 60 off a 4.0?

[turbovanman]

ya how would I swap the arm? pull apart the whole part across from where the throttle cables hook up to the throttle position sensor?

Remove the 13mm nut, pull off the arms, swap, reinstall, tighten nut. Couldn't be any easier. Just note how the spring goes.

[inmyshadow]

The 52mm TB is a direct bolt on. Using a caravan 58mm TB, the plenum needs to be ported.

The jeep 60mm TB is the wrong bolt pattern. Some neon owners modify it to use their neons. So it could be made to work.

later



What about a 60 off a 4.0?

[RoadWarrior222]

Without higher valve lift and duration, 55mm seems to be about the theoretical sweet spot as regards what a N/A 3.0 can actually suck. So 58mm is on the side of too big, but convenient. Have heard that optimal results have come from "porting and polishing" 52mm TBs. The 58 is reported a little bit pedal happy, and folks with anything larger have reported harsh tip-in and associated driveability issues for street use.

[93sundance]

Remove the 13mm nut, pull off the arms, swap, reinstall, tighten nut. Couldn't be any easier. Just note how the spring goes.

Where is the nut? I am looking at one right now and I see no nut.

[JDAWG]

Where is the nut? I am looking at one right now and I see no nut.

its behind the handle bars

[turbovanman]

Where is the nut? I am looking at one right now and I see no nut.

Holy crap, :(

Some might not have it, it could be welded, here are some reference pics-

http://i12.photobucket.com/albums/a228/turbovanman/Sonywork224.jpg

http://i12.photobucket.com/albums/a228/turbovanman/Sonywork223.jpg

[93sundance]

The one I have does not have a nut. It looks like the one in the bottom pic. I have a bunch of car parts and no car :(

[turbovanman]

The one I have does not have a nut. It looks like the one in the bottom pic. I have a bunch of car parts and no car :(

Swap out the shaft, grind down the bolts holding the blade in place and remove the bolts, slide out the shaft, reinstall with new loctite.

[Murphy]

anyone know the part number for the A/C belt with an under drive pulley?

would the stock fueling system be able to handle a 50 or 75 wet shot without a problem? i'm considering buying the NOS Sniper kit in the near future.

[Ondonti]

I think the stock pump flows decently as long as you dont have fuel pressure cranked up.

[RoadWarrior222]

Supposedly flows the same as the stock turbo pumps, and they seem to be good for up to 250HP or so.

[Ondonti]

Supposedly flows the same as the stock turbo pumps, and they seem to be good for up to 250HP or so.

250hp means nothing.


What matters is your fuel pressure. n/a will make more power on the same fuel pump because it doesnt ramp up fuel pressure in boost.

That said, I dont think anyone has a flowtest for the stock pump. That would be really useful for someone to do.

[Murphy]

I was thinking if I do NOS it I would install a new fuel pump first. should I have an A/F gauge for NOS? would it be recommended I buy anything like a bottle heater or pressure gauge?

[Ondonti]

I was thinking if I do NOS it I would install a new fuel pump first. should I have an A/F gauge for NOS? would it be recommended I buy anything like a bottle heater or pressure gauge?

bottle heater and pressure gauge yes!

Do you mean a narrowband or a wideband?

I think nitrous tuning with a wideband would be really smart. Most people seem to do it by "feel" or "when black smoke stops coming out" and that just aint right.

[Murphy]

I would want to do it with just a narrow band. are there nitrous jets and fuel jets and you need to match them up best to your application? what a/f should you aim for on NOS? is there anything else I should get for my setup? I should probably start a new thread about this.....

i'm only looking to do about a 50 shot.

[Ondonti]

I would want to do it with just a narrow band. are there nitrous jets and fuel jets and you need to match them up best to your application? what a/f should you aim for on NOS? is there anything else I should get for my setup? I should probably start a new thread about this.....

i'm only looking to do about a 50 shot.

I don't dabble in narrowband tuning so I cant really help you there.

Thats just not worth it to me.

[daytonaturbo87]

If you're running a wet nitrous system, the fuel jet for a given nitrous jet is static, not variable. You don't "tune" your fuel jet size. Back when I had my carb plate nitrous kit, it came with a chart saying if you want a 75hp shot of nitrous, use this size nitrous jet and this size fuel jet. If you want a 100hp nitrous shot, step up to this nitrous jet and this fuel jet. No ambiguity and there's no tuning, you use the jets they tell you to use for a given HP shot. A/F gauge not needed for that.

[Ondonti]

what fuel pressure do those charts assume?

[Murphy]

thats kinda how i thought it worked with a wet shot.

[93sundance]

Has anyone proved what removing the center divider in the plenum does to performance?

[daytonaturbo87]

what fuel pressure do those charts assume?

For the single fogger universal EFI nos kits it's 43psi +/- 5psi. For the carb kit like I had they assumed 5-10psi. I had a 7.5psi holley pump at the time so I thought that would be perfect. If you are running different fuel pressures than what their kits recommend you can call their tech line and they can tell you what jet to run. They always jet on the rich side just for safety anyway.

[Murphy]

installed the UDP, it feels to had made a difference.

[Vigo]

Removing the center divider in the plenum effectively doubles the plenum volume that any given cylinder will see. It'll help your high rpm power. Might lose some low rpm torque, but most people with 3.0s dont mind.

[Murphy]

is it possible to go too big with the plenum size? would a ported plenum and 1" spacers tbe too much? should I use a 58mm TB with a plenum that big?

oh and FYI, the dayco 15370 belt fit perfectly for the A/C with a UDP

[93sundance]

Not that I know of. yea use the 58.

[Vigo]

spacers dont increase your plenum volume. At least not the spacers people talk about for 3.0s. Its conceivable to make a plenum spacer that would add volume but noone has done it.

As far as the worth of the spacers, there has been much discussion and threads on it. i cant remember seeing a loss ever, but its a gain most people would say is not worth spending the money on. Some people need spacers to reverse their plenum, at which point any gain is a freebie.

[RoadWarrior222]

Here's the web archive of site of a guy who had nitrous in a 3.0 back in the day...
http://web.archive.org/web/20011218030239/http://www.members.home.net/lopezs/index.html

I had heard that one of the benefits of spacers was flow, in that they make the radius of the turn out of the plenum into the lower intake wider. Some guy, I think on allpar.com forums had got one flow tested for different spacer sizes and claimed the optimum was at 7/8"