Topic: ECU swapping questions

[mountain,man1]

Is swapping the stock ECU in a 88 4Runner really worth it and has anybody swapped the stock ECU for a haltech elite 750

[sirdeuce]

Going with any stand-alone ECU would be an upgrade to stock, uh, after tuning is completed. As far as swapping the ECU with an unmodified engine? A little more performance can be squeezed out in most cases, stock ECU tuning is more about economy and emissions than performance. With that in mind consider your possibilities without those strictures. Also, if any engine mods are put in place the stand-alone ECU can be tuned for any combination. But IMO changing to a stand-alone ECU for a stock engine is not worth the cost. How much disposable income do you have?

[sirdeuce]

If you were to get a stand-alone ECU installed, a dead nuts tune would maayybeee get you 10-15 more hp and 10ftlb torque. Not really worth the $1500 for a computer+ whatever installation and tuning would cost. If you live in a Smog state, like here in sunny oppressed Cali, and intend to use it as a daily driver, it could cost a lot more later in fines and towing and impound fees.

[Gnarly4X]

Is swapping the stock ECU in a 88 4Runner really worth it and has anybody swapped the stock ECU for a haltech elite 750

If you want to spend lots of hours and money on playing and testing with a Haltech, then yes… get one and get into the technical aspects of ECU tweaking and monitoring the results.  You’d need a really good AF meter and have a seriously well-tuned engine to test on. 

I believe the way you get more power when all said and done is to burn more fuel "efficiently". Like sirdeuce mentioned, you may end up with an emissions compliance issue, depending Colorado's current EPA conformance regulations.

With that said.... living in high elevations, tweaking the engine with an "adjustable" ECU could show some interesting results.  I like reading about engine tweaking. 

In high elevation tuning, generally you only have a few factors to play with:  Fuel octane, ignition timing, cam timing & valve events, fuel mapping (injector pulse width), and dynamic compression.  So, it would be interesting to understand what changes the Haltech could actually make that would significantly affect the power output? 

For me … I’d spend $800 or so on a Doug Thorley header and 2” free flow exhaust system and get an easy 1-day of work finished modification AND an extra 10 or 12 horsepower and about 10 more ft. lbs of torque right where I want it!! 

But that’s just my lazy thinking. 

Gnarls.

[sirdeuce]

2" or a 2 1/4" exhaust? The Thorley has 1 1/2" primary tubes and a 2 1/4" collector. Why would you choke that down?

[Gnarly4X]

2" or a 2 1/4" exhaust? The Thorley has 1 1/2" primary tubes and a 2 1/4" collector. Why would you choke that down?

That’s a good question.  As we know, we all have different experiences. 

Exhaust systems that are designed for, or installed on, street legal applications are often highly debated among some “experts” (4-into-1 vs Tri-Y).

Typically the bigger the better until you lose velocity, scavenging, pulse wave, and exhaust gas temperature, and many engine dyno tests show that.  However, with our 22RE’s it’s been discussed and in some cases that if you go too big on aftermarket exhaust – header, tubing, CATs, and mufflers – the low end torque numbers drop.  There is most often gain in HP in the higher RPM range, but the trade-off in low RPM torque is felt in your butt dyno and not what most of the 4x4 crawler-type wheeling community is looking for.

I experienced too big exhaust tubing and free-flow muffler with my first 1986 22RE, and ended up having it re-worked.  With my 1985 22R, I decided to stick with my past experience and keep the exhaust to 2” and a quieter turbo muffler.  It sounded great and did improve torque from off idle through the RPM range with the DT header and Double-Gnarly air filter mod. 

There are others who have made comments about a stock 22RE and going too big with exhaust flow.  But I have not seen any certified engine dyno tests to show this - only my personal experience the experience several guys I know who modified their 22RE exhaust.

I suspect that volumetric efficiency, velocity, and the ECU’s pickiness may be factors.

Gnarls. 

[sirdeuce]

Is the 'double Gnarley air filter mod' anything like my stacked K&N filters with a K&N filter top? Yeah, I did that one. Made a difference in performance, AND, actually reduced emissions over the stock air cleaner assy.. Guess the failure would come with the evap system as it opened the carb to the atmosphere.

I played with the exhaust tube size with several cars and trucks. I found the best OVERALL performance gains came with 2 1/4" tube/cat/muff keeping the system as straight as possible and using mandrel bends. That was with the stock cast manifold and downpipe. If you wanted to go 2" on the exhaust maybe a pacesetter header would do better for you, 1 3/8" primary tubes and a 2 1/8" collector. Stock exhaust ports, I believe, are 1 3/8" diameter. It would be a better match. Problem with that is the available header only comes 4 into 1 with long primary tubes. Now if you could find a 1 3/8" primary 'shorty' header your low RPM torque would be enhanced.

I might have mentioned this before. Being in CA I try to keep my engine looking as stock as possible. For the cost of a header(at the time) Extrude Hone could open the exhaust ports to @1 1/2" and I had a shop I went to for my exhaust where the tech made me a downpipe with larger tubes dumping into a 2 1/2" collector. That made a massive difference with that car(Celica). Oh the things I did back then.

[Gnarly4X]

I played with the exhaust tube size with several cars and trucks.

The Double Gnarly air filter mod is my experiment by stacking 2 stock paper air filters in the my 22R stock filter canister.  It made a very noticeable difference at freeway speeds with my added DT header.
I am not a fan of K&N air filters.  I spent about 8 years messing with those. I would not install those on any of my vehicles.

Yes… if you are eeking out every little bit of “exhaust enhancements”, mandrel bent tubing is the way to go.  But… for most of us cost vs performance is also a factor.

Regarding tubing size, I’ve always focused on getting those torque numbers up in the off-idle to 3500 RPM range.  HP at 5,500 RPMs is not where I need the power for my driving style.

Hands down, the best increase in power (cost/performance) for my 22s (and my other vehicles) is a header and opened exhaust!

Gnarls.

[emsvitil]

You can do a cheap mandrel bent tube by going up a size in diameter for the bends...…..... (as long as it's not a wrinkle bend)

[sirdeuce]

Regarding tubing size, I’ve always focused on getting those torque numbers up in the off-idle to 3500 RPM range.  HP at 5,500 RPMs is not where I need the power for my driving style.

Gnarls.

I'd lay odds that for better low end torque you'd be better off with a well built header with a smaller (1 3/8") primary tube and (2") collector than you have and carry that to the catalytic converter then increase that to 2 1/4" cat back. Let the header do it's job and not choke it with a small exhaust.
 If you are using a cat, use the largest you can. The restriction to flow a cat introduces is not really from the cat itself, these days the cat flows quite well, but from the added expansion of the exhaust charge from the heat produced from the reactive burning of unspent fuel. A larger tube after the cat can help with that.

Really, anything after the header is just for routing the exhaust to a spot to make it safe. Safe for you so you don't die from breathing exhaust and safe for your car so it doesn't catch fire from the heat of the exhaust. The exhaust mani/header should take care of all the magic to get the gasses out efficiently.

I can understand that 'driving style' bit. For me it depends on the vehicle I'm in and the situation.  In my Runner I keep the revs low and really don't care about acceleration, My MR2 I typically shift at 7200RPM where the power drops off, sometimes at the fuel cut, 8800RPM. The sound is awesome there! My 2WD truck putts around town under 2000RPM, but gets pushed to 6000RPM getting on the freeway.

[Gnarly4X]

I'd lay odds that for better low end torque you'd be better off with a well built header with a smaller (1 3/8") primary tube and (2") collector than you have and carry that to the catalytic converter then increase that to 2 1/4" cat back. Let the header do it's job and not choke it with a small exhaust.

When it comes to exhaust tubing diameter there’s tons of published charts, some good dyno tests, a bunch of marketing BS, and everyone else’s expertise or opinion.

For my 22RE and 22R, basically stock, or if I did a cam profile change, 2” tubing is plenty big enough, and should be good for between 140 and 150 HP with a target on mid RPM torque.

A quality mandrel bent exhaust from collector back, with a good free-flow CAT, if necessary, and a good free-flow quiet muffler should work fine. The tubing from collector back IS important.

I have to trust DT’s tri-y design as it is highly touted by many top racers and performance geeks.  And, without a Superflo 902S in my garage to test anything I'd create, I doubt I'd be able to come up with something much better than Doug Thorley has already done.

Again, I am just looking for 10 or 15 ft. lbs. increase in torque in my little 116 HP engine is all I need.

With a carb'd engine (slightly tweaked 22R and over 150 HP), I'd be considering a bigger exhaust tubing diameter... maybe 2.25".
 
Here's one example of a nicely simplified commentary on basic exhaust flow and tubing sizes. 

https://blog.tdotperformance.ca/guides/exhaust-back-pressure-how-to-choose-the-correct-exhaust-pipe-diameter/


Gnarls.

[Gnarly4X]

You can do a cheap mandrel bent tube by going up a size in diameter for the bends...…..... (as long as it's not a wrinkle bend)

Hmmmmm…. I don't see how there is a performance substitute for perfectly formed mandrel bent tubing? 

Gnarls.

[emsvitil]

The internal area of a tube goes down when you bend it (unless it's mandrel).

So you pick a bigger tube diameter that has the same internal area as a mandrel bent tube after it's bent.

[sirdeuce]

The internal area of a tube goes down when you bend it (unless it's mandrel).

So you pick a bigger tube diameter that has the same internal area as a mandrel bent tube after it's bent.

So you'd need to increase the tubing size for the bend and reduce it after the bend to mate to the overall exhaust tube size??

[sirdeuce]

It would be nice if they could develop a technique to bend "D" shape tubing. there is a good amount of info on the flow in a bend having a flat side on the short radius or inside of a bend. "D" shape ports are a fantastic improvement over round ports in a cylinder head. Imagine running bends in tubing for the building of exhaust systems.

[Gnarly4X]

The internal area of a tube goes down when you bend it (unless it's mandrel).

So you pick a bigger tube diameter that has the same internal area as a mandrel bent tube after it's bent.

Stepping up and down in the tubing may cause more disruption to flow than the restrictions caused by the crimping of the tubing in the bend?

If I'm looking for serious flow in an exhaust system, I'd just go with a professional mandrel bent system.

Gnarls.