Getting air thru a TBI

[rickhmn]

Seem like a few guys are planning to try to make N/A 2.5 and 2.2's competitive on short oval tracks. One of the points that everyone seems to agree on is that getting air into the engine and back out is the big problem. Given that what ever we do has to be "stock" (and cheap due to low claimer amounts) what ideas do people have. I know lots of guys say dump the TBI for a carb but I asked about this and they said no way and I think they'd notice that the TBI was gone and a carb in it's place. They also want to see the stock air box etc. I plan to take out any obvious restrictions in the box but what else can we do? I know that cheap, easy and lots of power are sort of oxymorons but there has to be some stuff we can try. I cross posted this on the induction side too.

[TurboTurismo]

Personally I use the 88-90 TBI omni airbox, it seems to allow more air in...Lifting the tbi off the intake is useful, more at higher rmp's tho.....

Robb

[speedyshelby16]

stock air box trimmed.

[TurboTurismo]

+1 on that, I just worry about hot air getting in there...I see there is no factory EGR provision that tbi intake.......

Robb

[Wizard]

Yes there are.

There are two TBI intakes with different EGR port locations. One I think this one picture shown is early one with EGR tube coming up at rearmost center of intake's bottom. That EGR valve is on the #4 exhaust runner.

The later one had the EGR valve sitting on top left of the TBI.

BTW, TBI and carb use same exhaust manifolds.

Cheers, Wizard

[RPMurph]

Like the guy said in your other post, you can remove the coolant lines from the intake, but the engine will bog down low.

you can swap to the l body TBI intake with a v6 bottom end to make for an easy CAI


Pic origionally posted by dodge78



you can add a couple extra TB gaskets. I switched to studs instead of bolts, so I think i have about 4 gaskets in there now. I think porting the intake manifold would be very helpful once you move the TB up higher than the stock level.

I also removed the balance shafts which seemed to help out my power alot

for cheap power on a TBI, Allmotor always said to mill the head. I cant remember if he said .040 or .060, but i would go .040 just to be safe

NGK ZFR5N or Autolite 985 some people claim they do alot better than stock plug, i really cant remember

somewhere on streetfire i have a 0-105 vid of my car, that wasa couple mods ago tho, should be a lil bit faster(just a tiny bit lol)

[DaytonaTurbo87]

I've noticed some of the 2.2's use a different throttle body. It bolts to the same intake, but instead of using the big air cleaner box, it's got a round hose attached to it leading to an air cleaner box like a V6 or turbo intake does. I've come across these several times in the junkyard, it seems they would flow air much more smoothly into the intake, plus it'd be easy to rig up your own cai if you wanted.

[TurboTurismo]

I think that different tbi was on the 84 model year and I am pretty sure they had 100hp vrs the later tbis at 92 and 93 hp?, This is kinda off topic but hear me out and please correct me when wrong..Thanks !! I have done some research as of late to see if no egr was beneficial other than keeping the engine cleaner. I think Ill just leave it as is, some people say egr adds power by lowering the temps? Just great ! I should have done more research before I went yarding..LOL, Now I have a Canadian/Federal emissions 94 tbi sbec for spare and it doesn't have the egr solenoid driver turned on and I also got the manifold without the provision for egr for spare in the storage room . I just heard that when chryco did not use egr on cars they recaled the computer and made the cars run richer to keep the intake charge colder at cruise to prevent ping as where with egr they could allow a more agressive fuel curve,, Just what I have read, not sure how true it is tho.. so I guess I wasted my money gettin this stuff as it seems it would make the 2.2 tbi slower,bummer if true,, correct me if I am wrong but If you tried to raise the base timing the comp would lower it anyway to save the engine? does egr allow for more timing? oN A DIFFERENT NOTE....I use the box off a 90 omni and its gutted as I do not drive the car in the winter anyway........I think I may get the bottom half of a box like shown above with nozzle at the front..should be able rig something up.....

Robb http://www.cardomain.com/ride/2291434

[joker5k1]

If you're feeling gutsy and you can do some fab work, what about using the cleaner assembly off of a 4.7L, or the 5.2/5.9? I know the jeep assemblies go to the drivers side, but i think the dodge (Durango, Dakota, and Ram) go to the passengers side.
here's a Jeep assembly:
http://www.wjjeeps.com/engine_air_4.7ho.jpg
Here's a dodge assembly:
http://www.dakota-truck.net/UPGRADES/FABM/fabm09.jpg

-Joe

[TurboTurismo]

Hey Joe, I like the one for the Dakota for sure Looks promising for a fab job for sure

Thanks
Robb

[DaytonaTurbo87]

Having or not having egr should not make you faster or slower. You're not using the egr at WOT anyway, just during cruise/light accel. It's just more of a emissions/mileage thing. Has a two fold effect, first one being burn up the left over oxygen in the exhaust, second is to just take up space. The left over crap that's not combustable just takes up space in your combustion chamber, sort of like artificially reducing the size of your combustion chamber, causing the computer to need to inject a little less fuel to maintain stoic. At least that's the way I understand it anyway. I've tried on a carbed 2.2, drove it with egr, then ditched it and put on a block off plate. I noticed no difference. Probably the only way you would really notice a difference is if your egr valve is sticking open, then getting rid of it would make your engine run better. IMO the heated air inlet in the heater box makes more of a difference on mileage/power than the egr, which is more for emissions anyway. I mean, the T2's and the 2.5 T1's didn't even have an egr setup cause they didn't need it to pass emissions testing at the time. You should not be pinging just because you got rid of the egr. If your egr doesn't work, some years will just store a code saying no a/f ratio change when egr solenoid activated. The computer just says, oh that didn't work, and goes about it's merry way. If you're pinging because of that you have problems elsewhere.

I think next time I go to the junkyard I'm gonna grab one of those older style TB's and just slap it on my 2.5 to see if it makes any difference.

[RPMurph]

can someone show me a pic? I would be interested in getting one, i know there are none around here tho

[TurboTurismo]

I posted here about the 1994 dodge shadow pcm/sbec that doesn't have egr turned on, its a Canadian/federal w/o egr aswell as the intake not having a provision for egr, I have both in my possesion .I had asked how they programmed the the comp to not see egr, as in how basically did they make the engine not ping during cruise?..any idea?....Did they recal the comp to have retard timing during cruise or something..with the 94 setup w/o egr how did they cool the intake charge?..what about raising the base timing to 15 deg w/o egr?..premium fuel? this stuff is messing with my mind>>LOL I just need to understand why everyone says PING engine damage unless the intake is cooled by egr....

Robb

[Wizard]

The duration/overlap of the cam is what makes the difference.

Since I'm putting the N/A MPFI on 2.2 from scratch (not TURBO!!) what air box stuff is easier to adapt from junkyards?

Cheers, Wizard

[DaytonaTurbo87]

Quote:

Originally Posted by Robb PING engine damage unless the intake is cooled by egr....

Did you not read what I just posted? Anyone who says you need egr to not ping is full of crap. You don't need egr. I plugged and disconnected the egr on a 2.2 with no problems, no ping. If you're pinging it's not because you don't have egr.

If you're pinging it's either because you have a vacuum leak somewhere, and a big one at that for the 02 to not be able to deal with it, you're running too hot, too much base ignition timing(try 10-12* and go from there) or a plugged injector. Also I've had engines that pinged because the carbon deposits in the combustion chambers. Pulled the heads, cleaned em off with a dremel, put back on and no more ping.

The computer is programmed to operate both with and without the egr system on. If it tries to turn on the egr and it doesn't work, it just stores a code saying no a/f change with egr solenoid activation, that's it.