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View Full Version : School me on 5.0s



SVT10th
07-18-2013, 09:28 AM
Ok, been a long time since I've worked on a 5.0.

I want to make my 1990 'vert with the AOD a little faster. Right now it makes lots of nice noises, but it's all bark, no bite. It doesn't need to be a race car, but if it could take on a Civic without embarrassing itself, I'd be happy. I want to do this without spending much money. This is supposed to be a cheap, fun car, not a money pit.

The other day it got a set of 3.55 gears which made a difference. When it was up on the lift Rick and I saw that it also has shorty headers and a full MAC exhaust with hi-flow cats. So I think it breathes out OK but probably needs some intake work. Everything intake side is stock.

I know I'll need a CAI of some sort (or at least a K&N drop in), and upsized MAF and throttle body. Any suggestions for size? I've heard 65mm mentioned on some forums as a good size for a basic street driver.
How about intakes? A Cobra or Explorer intake will fit apparently and I've heard they are a good for low-cost, mild upgrades. Do I need to do both upper and lower? Anything tricky about it?

Finally, anyone have any 5.0 parts lying around they'd be willing to part with?

ToplessPony94
07-18-2013, 10:17 PM
Jim, as has been said before, an engine is basically a pump. You can't take in more than you can put out and you can't push out more than you can take in. You are correct that you are losing much of the benefit of your headers and exhaust by having a stock intake. Yes, you need a CAI. BBK makes a decent one for that car. Don't bother replacing the stock filter with a K&N - get the whole CAI. Not that much money and it helps a lot.

Personally I went 75mm all the way from the MAF to the TB to the intake plenum. Some people say it's better to get smaller as you get closer to the plenum to increase the flow pressure, - I felt that was not right. If you want to go that route, then a 70-75mm MAF into a 65mm TB would be the thing to do. The Explorer plenum will fit the stock lower and will give you better performance. I don't believe the Cobra plenum will fit the stock lower properly, but I'm not sure.

You will definitely get better performance (at a higher price) with a Trick Flow Street Heat (or a Holley SysteMax) 75mm inlet plenum than with the Explorer plenum.

You can do all of the above with the stock 19# injectors in place or upgrade to 24# for more of a gain. In any case you should get a tune after doing any of this stuff.

As for available parts, I have much of the stock stuff I took off my car, but the only thing you would really be interested in is my stock fuel rails with an adjustable pressure regulator. The 94 rails are higher capacity than your stock rails and better quality, too. They are not drop-in fit - they would need a little bit of bending to mate properly with the rest of your fuel system, but nothing Rick can't handle with ease. Let me know if you want them.

One last thing: You should be able to replace the stock 1:1.6 rockers with 1:1.7 Cobra rockers and get a power boost, as long as you stay with the stock heads. If you replace the heads, you may get piston/value clearance issues and the fit would need to be measured. The Crane 1:1.7 rockers for your car are what the Cobras run. (If you order them, they will say Crane on one side and Ford on the other side!) They ran fine with my stock heads while I had them and the difference was definitely noticeable. I don't think I still have my Crane rockers, but you are welcome to them if I do.

Hope this helps some.

LILBLKSNAKE
07-18-2013, 10:30 PM
Personally I went 75mm all the way from the MAF to the TB to the intake plenum.
I did the same and had my COBRA intake opened to 75mm too.


The Explorer plenum will fit the stock lower and will give you better performance. I don't believe the Cobra plenum will fit the stock lower properly, but I'm not sure.
Explorer upper is essentially a GT40. You need an explorer or GT40 lower. None of that stuff will match up to the stock upper or lower I have a ported explorer lower and ported COBRA upper


You can do all of the above with the stock 19# injectors in place or upgrade to 24# for more of a gain.
Stock 19's go a long way on an NA car. On a 125 shot of Nitrous the car is probably pretty close to maxed but with Pete's tune it runs as perfect as my 2013. I do have a set of 30lb'ers from El Presidente' though :)

SVT10th
07-19-2013, 09:09 AM
Considering whats done to the car now, and if I do the CAI, upper and lower Explorer intakes, what am I looking at for gains? IIRC, they car dyno'd about 170rwhp last time Matt put it on the rollers. (which was probably after the headers and exhaust)
Based on a quick Googling, I'm looking at probably $400-500 for CAI, and intake set if I can find some on EBay, etc.
Is it worth it? If I'm only going to get 10 hp out of it, it's not worth it. For 30-40 or more hp, it might be.

Anything tricky about doing the intakes? Something I could do in the driveway (no garage), or is it more involved/time consuming than it looks?

TorchredSVT
07-19-2013, 09:23 AM
Personally Jim....keep it stock...maintain it and just enjoy.

It runs, it's reliable, its fun....so why mess or tinker with it. Throw your money at making sure its road worthy and will stay that way.

just my. 02 cents

SVT10th
07-19-2013, 10:59 AM
Personally Jim....keep it stock...maintain it and just enjoy.
It runs, it's reliable, its fun....so why mess or tinker with it. Throw your money at making sure its road worthy and will stay that way.
just my. 02 cents

Well, I'm afraid a 14 year old girl on a Vespa will want to race for pinks and I'd have to turn her down for fear of losing.....

ToplessPony94
07-19-2013, 12:12 PM
Jim, the CAI alone should net you 10hp gain with those headers and exhaust. I would guess the bigger MAF, TB and intake would be good for roughly 20-35 hp or more depending on exact configuration.

My 5.0 with 1-5/8 headers, 2.5" H-pipe and cat-back, CAI, 75mm MAF and TB and Trick Flow Street Heat intake and the 1:1.7 rockers was pushing 250-260 rwhp before I did the heads and cam. Stock on mine was 215 at the crank.

LILBLKSNAKE
07-19-2013, 08:12 PM
1 5/8 headers, off-road H, Cat-back, CAI, 75mm MAF and Throttle body, Ported COBRA intake, stock heads and cam I put down 250rwhp with Pete's tune and no juice.
Personally, I would save up your money and just get a whole Trick Flow or Systemax top end kit. Don't waste time and money on the explorer junk if you plan on doing anything else down the road.

Or you could just Coyote swap it

ToplessPony94
07-19-2013, 09:32 PM
1 5/8 headers, off-road H, Cat-back, CAI, 75mm MAF and Throttle body, Ported COBRA intake, stock heads and cam I put down 250rwhp with Pete's tune and no juice.
Personally, I would save up your money and just get a whole Trick Flow or Systemax top end kit. Don't waste time and money on the explorer junk if you plan on doing anything else down the road.

Or you could just Coyote swap it

I pretty much agree with Ed, except that doing the CAI now is still a good option, as well as a 75mm MAF programmed for CAI.

LILBLKSNAKE
07-20-2013, 01:23 PM
I pretty much agree with Ed.

Coyote swap??

SVT10th
07-20-2013, 10:32 PM
Jim, the CAI alone should net you 10hp gain with those headers and exhaust. I would guess the bigger MAF, TB and intake would be good for roughly 20-35 hp or more depending on exact configuration.

My 5.0 with 1-5/8 headers, 2.5" H-pipe and cat-back, CAI, 75mm MAF and TB and Trick Flow Street Heat intake and the 1:1.7 rockers was pushing 250-260 rwhp before I did the heads and cam. Stock on mine was 215 at the crank.

Those are reasonable gains. That might be worth the investment.
Anyone have experience with the K&N FIPK for the Fox 5.0s? (As opposed to BBK) I had one on my 02 and got good gains from it. I know you lose a coupe of hp by staying in the engine compartment, but I hate in-fender CAIs.

SVT10th
08-04-2013, 04:48 PM
Well, you know how sometimes it's the solution is so simple you don't even think of it. After taking it for a ride, Rick suggested I play with the timing.
I remember from my days with my 87 GT that back then I adjusted the timing as far as I could without getting any knocking. So I dug out my timing light and distributor wrench that had sat unused for about 25 years. I hooked it all up, pulled the little timing plug, and took a read. Holy crap, it was firing at 0° TDC. No wonder it was a dog. I adjusted it back to where it should be (around 12) and it could tell just from the idle that the car was running better. Took it for a ride and it was like a whole new car. Brought it home and played a bit more. Finally got it up to about 14-15° and it's a totally different beast.
Power is right there on tap, it smokes the tires at the slightest urging and pulls hard right up to 5500 rpm. BEAUTIFUL!
You should have seen the grin on my daughters face at "punch it" time.... NOW the 3.55s are really doing something, too.

I can probably get a few more ponies if I run high test in it and bump the timing some more. Have to decide whether I want to make it a "premium fuel required" car....

chachee52
08-04-2013, 08:08 PM
You sure the smoke isn't coming from the exhaust? HEHEHEHE
Congrats on the easy fix. One of these days I will have one of those with my car!

TorchredSVT
08-05-2013, 09:36 AM
thats awesome jim!! now get out there and enjoy it