How to get 200 crank HP out of a n/a 3.0?

[DaytonaTurbo87]

I'm sure I saw a post somewhere here on td years ago of a guy who did some boltons to his 3.0, took it to the dyno and got around 175whp. I tried searching for it buy couldn't find it.

Not looking to go turbo, but I didn't know where else to post this.

I would like to 200 crank hp out of a 3.0. Any exhaust headers available for a daytona with the 3.0? If not I'll have to see if there's any useful porting that can be done on the exhaust manifolds. I was thinking that would work well coupled with a 2.25 or 2.5" exhaust system. Could pull the intake manifold and smooth it out a bit on the inside with the dremel and go to a bigger TB off of a 3.3/3.8. Bigger injectors and an adjustable regulator so it could be tuned. A decent quality CAI and of course all the tune up items like plugs, wires, etc etc. I heard the underdrive pulleys aren't produced for the 3.0 any more so those would be hard to find.

That's pretty much all I can think of for easy bolt-ons, but I don't think that'll get it up to 200 crank hp, I'm thinking more like ~170 at the crank?

[1983Rampage]

I really do not know if this is true, I have not done a whole lot of work with the 3.0's but I heard somewhere that you can put the 24v headers off of the 6g73 2.5l engines and put them onto the 3.0l 6g72 engines. I figure that would be a good way to start with the increase in horsepower. But this is just hear say, I bet that there are other people that could confirm this or say it is wrong.

[Shadow24V]

AFAIK the 24v headers have a different flange, however i think you can get some for the 12v 3000GT and mod them (may need flanges, not sure though)

id think that the following would aid in N/A hp
10:1 CR pistons (diamante IIRC)
Cams/cam gears
PnP the intake and heads
bump ignition timing


there is probably more, but i dont have the 12v anymore (24v SOHC FTW :-D) so im not up to snuff on the 12v stuff

[mopar3.0]

ive got the grand prix headers on the way, fit with some mods,

[c2xejk]

Interesting I was doing some calculations along these lines today. Based on dyne data, a modified 3L (stock heads) would produce ~129whp (AT) or 161 chp. Stock heads at stock lift is ~160 CFM. Very close to 1 chp/CFM.

My van ~155 whp (MT) or 182 chp. The heads on the van at the time flowed ~176 CFM at stock lift. (>1 chp/CFM)

So to start with you would need cylinder heads that flow at least 200 CFM at the peak lift. Then you would need to make sure the rest of the engine is up to par.

Throttle body, I can't see less than 58mm being needed.
Manifold. Well ported
UDP
CAI
Properly sized header would be helpful...
etc...


For the past month or so, I have been toying with pulling the van's heads off and tweaking the porting to bring it up closer to 200 CFM. Right now I am expecting ~190 CFM. The best way to get to the 200+ CFM point may be oversized valves.

[DaytonaTurbo87]

Sounds like head flow is the big problem. That would be a good side project, overhaul a spare set of heads with bigger vales and some porting. However it doesn't take 1cfm for 1hp. I know on V8's you have the potential for 2hp per cfm and I think V6's are 1.5hp per cfm. Of course that's on a well though out race engine, not an econo-designed V6.


How far do the 3.0's pistons sit in the hole? While more compression wouldn't hurt, going from about 9:1 compression to 10:1 compression won't result in more than a small % horsepower increase. I know one of the mopar mags tried this on the dyno with big blocks and saw around 5% increase in power for every 1:1 increase in compression with everything else being exactly the same.

What's this about grand prix headers? I've never heard of this before. I have a hard time believing they will fit?

[Ondonti]

Sunmind put down 220whp in his sohc 3000gt in 2007.

He basically did all the mods I have but high compression to compliment n/a performance and much higher dollars on everything.

Cams, heads with oversize valves, headers, intake work, then full engine management for tuning.

[c2xejk]

Quote:

Originally Posted by DaytonaTurbo87 Sounds like head flow is the big problem. That would be a good side project, overhaul a spare set of heads with bigger vales and some porting. However it doesn't take 1cfm for 1hp. I know on V8's you have the potential for 2hp per cfm and I think V6's are 1.5hp per cfm. Of course that's on a well though out race engine, not an econo-designed V6.

Generally, to get the higher hp/CFM ratios, you need more RPM. To get more RPM you will have to crack the ECU or go with a MS unit...

That said, there are a few other cylinder head flow variables that can be tweaked to bring up the hp/CFM number some. Particularly velocity.

My most recent set of heads (going on my turbo engine) had the velocity starting at ~275 fps at 0.35", have to see how they work once I get the engine running. Velocity peaks out at ~300 fps @.5.

Quote:

How far do the 3.0's pistons sit in the hole? While more compression wouldn't hurt, going from about 9:1 compression to 10:1 compression won't result in more than a small % horsepower increase. I know one of the mopar mags tried this on the dyno with big blocks and saw around 5% increase in power for every 1:1 increase in compression with everything else being exactly the same.

The stock pistons do no sit down in the bore... To increase the CR you would need aftermarket pistons with a smaller dish/CC volume. If you are staying NA, you would definitely want to bump up the CR... If a built NA setup is step 1 on the way to a built forced induction setup, then you would need to find a "balancing" point... (Note that this ie one of the other state of tune items that increases the CFM/hp ratio.)

Quote:

What's this about grand prix headers? I've never heard of this before. I have a hard time believing they will fit?

One person here is in the process of modifying grand prix headers to fit our engine. Based on some earlier header tests, the tubes may be oversized... Right now I wouldn't recommend tubes more than 1.5", maybe 1.25" if you can make them fit.

Do you have a budget for this project? (ie. how crazy are you willing to go?)

[mopar3.0]

eererere

i am not cutting up the front header like this

[DaytonaTurbo87]

Well thanks for the info. This is actually for my younger brother's car, my TD days are very limited, most of my $/time goes into my roadrunner clone. His budget is limited so things will slowly be done over the long term. Just wanted to see if there's places to go with it tho. Bang for your buck, doesn't sound like the V6 has very much potential.

[Shadow24V]

the ECU is the real hangup, its a miser with fuel so even if you did get a bunch of mods done, its a fight to keep from being lean. MS is probably the least expensive ECU option ATM, unless someone cracks the stock ECU and does Cals.

my 24v which is essentially the same motor with better heads and a 9:1 CR and on a good tune could potentially hit 200Whp, and is stock "rated" at 205chp so its not impossible with this motor.

[DaytonaTurbo87]

Yeah, MS is an option, I have a MS-2 for my 440 project. At least you could get a tune going then. But so much extra work considering how little the mods are you're doing to it. But thanks for your input all, at least now I got a pretty decent idea of what to do.

[L_P]

On your 6G72 check out various 3S performance shops. There is long tube headers but they are an arm and a leg. Go cat less and a free flowing exhaust should help out. Port and polish the heads. There are a few places that have upgraded N/A cams or get some custom grind cams. Should get you up there if not well past it. the 3S came stock with the 220BHP may just be a few swaps.
check out 3sx.com they have the long tube headers and goodies, you may have to modify them a little to fit.

[comp]

Quote:

Originally Posted by mopar3.0 ive got the grand prix headers on the way, fit with some mods,

can you add some pics ???

[ATaylorRacing]

I used to drag race a 94 3.0 Duster with an automatic that had @ 165 hp at the tires and about 175 @ crank. The biggest gain was an under drive pulley kit, getting rid of the stock a/f assembly, making a home made ram air set up, and a TB from a 87 3.0 mini-van. All that picked it up over 1/2 second and improved fuel economy by over 3 mpg. I also used a gutted cat and 2 chamber flowmaster ONLY after these previous mods were done. When I first got the car...NEW...I took it to the track with an electric sawzall and a Super Trapp with 24 discs and longer mtng screws. After 2 passes I cut off the muffler, the car slowed down! I put on the Trapp with no discs, still slower by less. I put in 12 discs and quicker, but not as fast as stock. It took 18 discs to make tyhe car .1 quicker than stock exhaust! After all the other mods the car ran quicker yet with a dump before the gutted cat. At @ 25,000 miles the car picked up @ 1/4 second with no other changes...must be broken in. The car was gutted down to 2450 lbs and ran 15.1s with my 265 lb butt in it, but putting my 140 lb son in it for his 1st pass ever down the 1/4 made it break into the high 14s.....I also had a 10% lower gear ratio and 20x8x14 slicks.