I've been considering swapping out the 87 T-Bird 5.0L stock upper intake, throttle body and EGR with that from a 87 Mustang 5.0L HO. That will be going from 50mm opening to 65mm. Has any one ever tried this or have just upgraded to an aftermarket 65mm setup? If you have done this what effects/results were achieved?
Messing with a speed density system is like play Russian Roulette if you do not understand what you are doing. If this will result in more air getting in to the cylinders then you just hope that the EEC can compensate but my experience with SD has only been with race cars and tuned with a laptop.
I can't remember what the EEC can adjust for until it pegs out the trim tables. 25%? I think the WOT fuel tables are also updated by the closed loop trim tables.
Stay under ~25% increase in engine airflow and you're probably okay. Go beyond that and you'll begin to lean out at WOT and start to encounter a bunch of other issues that can't be 'learned' for.
SD is great for reliability and cost for OEMs, but I think MAF systems are way easier to tune. You're directly given air flow, so you mainly have to make sure mods don't screw up timing tables.
I did the HO upper/TB years ago along with factory HO headers and 2.25 dual exhaust. The factory SO speed density computer handled it fine with no issues.
I did a similar upgrade but with headers also a few years ago and had no SD issues. If you're like the rest of us though, you probably won't be able to stop the mods at that point so you might want to brush up on the MAF conversion.
Gotta start somewhere, right?
It shouldnt bug the computer much. Check out the "mid h.o.conversion" on coolcats.
The SD system is fine with mods till you start messing with cams and big valve heads... Even then the Mustang system with 19Lb inj is OK with something like GT40 heads, still basically have to leave cam close to stock...
As a direct response to OP, my answer is almost nothing. While the 50mm opening and small plenum volume of the SO intake are a limitation, they're not THE limitation. Your largest obstacles are going to be the single 2" exhaust (even with y-pipe in, y-pipe out duals, you still only can flow as much as can get through the single between the Y's, so it's still single exhaust), and after that the E6 heads, after that you run out of intake (with SO upper and TB), and shortly after that the cam is too small, and once you go to a larger cam, you'll immediately require higher capacity injectors.
HO life is all or nothing.
Heads, cam, intake, exhaust, EEC. Every upgrade you take from the Mustang 5.0 market will require that you're first converted to HO, if not HO and MAF.
I noticed a bigger difference from pulling out the silencer from the fender then the h.o. Intake on a stock s.o.
Stock SD setup, I added HO upper and TB, stock mustang headers, 2.5 H pipe, with dual exhaust. Noticed no running problems, not sure if I noticed much change performance. It was along time ago since I drove a stock one though.
Actually that will be going to 60mm, no 5.0 Stang had a 65mm TB stock... The opening in a SO upper is approx 60mm, the 200Hp '86 HO used this intake with a 58mm throttle body...
As others have stated you'll get more performance with headers and true duals than the intake swap... All that's beneficial on top end would be the 60mm TB & EGR spacer... At that point either go big(full HO) or leave it alone...
My car did well with Mustang upper and tb. The power increase wasn't huge, but it was noticeable. I was conditioned to the stock car and no experience with any other vehicle at that time (it was my first car). I believe it simply leaned out a rich factory WOT mixture a tiny bit, which shoots for around 11.6:1 AFR for 100% gasoline. I didn't do any other work until the entire motor was swapped out years later - stock exhaust, heads, etc.
When working with only ~150hp and the limited acceleration you get, small increases are noticeable. Going from 150hp to 160hp (not saying this is what to expect) could feel like a much bigger increase than going from 400hp to 450hp.
I don't think I'd notice a small power increase today. Upper intake and silencer is a cheap update to make though - you can get them for $20. Electric fan is another easier swap that can help free up power and increase fuel economy, but I had a (Mark VIII) fan failure within the first year, leaving me without active cooling.
Now that you mention that you're right, 65mm was an aftermarket upgrade.
Magazine articles always talk about the Mustang and those changes but nothing for a T-Bird. I was just not sure that the stock ECM in the T-Bird could handle changes.
Other changes I've made in the past are as follows:
>Removed air silencer in early 90's and have a KN filter.
>Replace stock exhaust in 95 when it rotted out with the Borla Turbo Coupe 2.5" stainless steel of that time ( No longer sold ). Wanted stainless steel and if I recall there were no Mustang stainless systems at that time. To get it to work it only required a custom bent pipe between Cat and Borla pipe.
>Changed rockers to 1.7 ratio in 98 hoping to gain some extra hp but did not notice any extra.
>Had to replace Cat in 2005 when car failed EPA pollution test. Discovered the inside of Cat was hollow. Now since my state only tests cars with the OBII I am free to do whatever changes my wallet allows.
Have never felt any hp increase with any of those changes. So I was thinking that either the stock intake or exhaust manifolds is holding back power gains. ( Heads are a big change for me. ) I know if I went with shorty headers I'd have to get Mustang duals because of difference in the exhaust connections. So I'm thinking of changing to the upper HO and since the lower manifold is the same on either engine.
Ford did a disservice when it limited the standard 5.0 engine in T-Bird to 150HP. When I bought the car back in 87 every dealer I went too was always asking more than MSRP on the TC just because of the 190HP. I remember they never allowed a test drive either on the TC. I wonder what 190HP or more feels like in the T-Bird? Probably twisted the hell out of the body because the body on my car has about a 1" twist in it.
GT40 Explorer intake and TB are 65mm. If you're going to start swapping stock parts for performance, I'd completely skip over HO parts, except the HO cam and EEC. The GT40 heads are good, and actually breathe, and even the Explorer variant intake runs within 10% of the flow (when ported) of the best the aftermarket has to offer, and offers more low end torque than anything.
At this time my funds are limited and the HO TB/EGR, Upper intake are parts I have on hand.
LOL 190Hp isn't going to twist anything... I've hit mine with 125/150Hp shot of nitrous for aprox 440Hp total, still sets level...
From what I've found about fox body cars you're very fortunate to still have a level car.
I have e5 heads ho intake and tb ho headers 2.5" exhaust no smog or egr and the engine runs great
You've got WAY too much exhaust for those heads, that cam, and 14# injectors. You're probably giving up power having such large piping. A Mark VII 2" H-pipe would probably make more power with your combo, especially at low RPM.
Or, go full HO swap (heads, cam, injectors, EEC) and be just a little excessive.
Think of it like trying to blow out a candle while blowing through a 2" pipe that's 2 feet long. You lose so much velocity, that you can't get the work done. The same task with a 1/2 or 3/4 inch tube would be successful. Exhaust gas has inertia, so if you keep the velocity up by using appropriate size tubing, the momentum of the exhaust in the pipe will help to evacuate new exhaust from the ports (and cylinder) with greater efficiency by creating a lower pressure area at the port. It's called cylinder scavenging, and overkill is a thing.
Yeah I know, I had and have a lot planned for the car. I have 3.73 gears, worked e7 heads, a 95 gt cam and plenty of other parts sitting in storage. But I hit a massive deer with my daily and combined with job issues and the sad fact that 3/4 slip super bad I kinda just gotta live with it at the moment. :/
Nah. It's fine. Subframe connectors and it's golden. Been beating on my car for years and it's still level.
What??? Maybe 3-4Hp??
Always go big so you have room to grow...
If a person was in some kind of spec racing class I can see where tuning the exhaust to the motor makes 100% sense but in this case with the future mods he is going to make then the 2-1/2" exhaust is money well spent. My 331 wants more exhaust than the 2-1/2 but with the torque arm and panhard bar that is all its going to see.
Since the bottom portion of both intake manifolds are the same the H.O. Manifold bolted right on with no problems. Added the H.O. Throttle Body and EGR Spacer and then just switched over the Non H.O. TPS, Idle Control Solenoid and EGR. Made a little adjustments on the TPS position and base idle screw and engine runs fine. No surging or off idle stumble. All this may of been a wasted effort because I don't notice any more HP even with 1.7 ratio Rocker Arms. I've got shorty headers and the H.O. Mustang Cat forward exhaust I could install but that probably won't add any HP either. For any real HP gains I guess I'll have to open the engine up and put in a different Cam and Heads that have a higher compression ratio. 150 stock HP just doesn't cut it on the road anymore. It's okay in the city and it gets great MPG on the highway. Can still get 30 Highway MPG after 31 years. Just have to be careful when passing other cars.
If you are going to open up the engine then just convert to mass air. Watch the 1.7:1 rockers with a cam swap and the pistons as you may not have the reliefs in your pistons like the Mustang HO motors.
Funny thing is when I put long tube headers and a full dual exhaust on the stock throttle body 302 in my '83 is made a huge difference. Have you done a leak down test on the motor to see if you have good compression on all cylinders? Could also be that any additional power you are gaining is just blowing through the converter on the trans. My just be a time in the river thing after 31 years.
I thought a few guys had used 1.7s with stock HO spec cams (like 87-93 Mustangs)with no issues? I could be mistaken. What was the difference on the 93 Cobra cam spec? Didn’t they have 1.7s? Sorry to derail the thread...
93-95 cobra did have 1.7's, but they were also mass air.