H22 Tuning.

[tg1_in_france]

Hi everyone,

I’m playing around with the idea of building an Attack. I’m thinking of going along the KISS theory, keep it simple stupid and stick with the H22 engine. I don’t want to turbo/supercharge it to avoid the cooling problems.

What power/torque gains could I make by n/a tuning? What are the best techniques for doing this? Can anyone suggest any web sites that have good information about tuning Honda….. or any other engines for that matter? I want to learn as much as I can before embarking on this.

Thanx

The Ginger One

[ozarkbw]

www.h22a.org
www.honda-tech.com
www.teaminterlude.com
www.hondaswap.com

That should give you enough reading for today. There will be another assignment tomorrow...

Daemione probably knows of some good Prelude sights also.

[Daemione]

For H22 specific tuning, www.preludeonline.com I think has the most dedicated & knowledgable group of users. Excellent information in the archives & FAQ's. It is a pay site, though . . . . $6/year ($6.53 if by paypal). Honda-tech also has lots of smart folks, but the board is more cluttered & the search engine is terrible.

When you ask "What power/torque gains could I make by n/a tuning?", what sort of budget do you have in mind? A basic complement of bolt-on breathing modifications (intake, header, exhaust, & cams) costing anywhere from $2,000-$4,000 may garner anything from 10-50 hp.

This topic is far too broad to cover in a few paragraphs, but here's a few things that might help get you started on what you want to find out more about.

The basic premise on how to increase torque output (and consequently, horsepower), is to either:
a) increase the amount of air & fuel the engine can ingest by either increasing volumetric efficiency, adding displacement, or using forced induction.
Or
b) increase the efficiency in which that air & fuel is burned - i.e. improving thermal efficiency. Things like a higher compression ratio, better burn characteristics, stronger spark, & improved ignition tuning can help in this area.

On a n/a application, there is a finite amount of air/fuel your engine can process. On a highly tuned application, this works out to anywhere from 70-90 ft/lbs. of torque per liter of displacement (dependent on how it's measured). Once that limit has been reached, the only way to go faster is by moving (or even better, maintaining) that torque to a higher rpm, and combining more aggressive gearing to take advantage of it.

Of course, all of this is much easier said than done, as there are hundreds of variables that come into play when you begin modifiying an engine beyond it's stock parameters. Fuel & Ignition maps, appropriate gearing, valvetrain, heat, etc.

Hope this helps you get started . . . .

[tg1_in_france]

That's great. Certainly gives me something think about.

Thanx

The Ginger 1

[flyrod]

This thread on H-T shows a variety of results:

http://www.honda-tech.com/zerothread?id=576927

It should give you an idea of the possibilities out there...

[Daemione]

One thing I forgot to mention that's worth discussing is parasitic & inertial losses . . . . No matter how much power the engine is making, what's actually getting to the ground is what counts. Lots of power can be "found" by making changes in this department.

Examples would be:
underdriving (or eliminating) power steering & A/C
eliminating balance shafts
electric water pump

And of course, any weight you can lose from the drivetrain . . . pistons, rods, crankshaft, crank pulley, flywheel, clutch, axles, rotors, wheels, tires . . .

[ozarkbw]

Originally posted by Daemione
And of course, any weight you can lose from the drivetrain . . . pistons, rods, crankshaft, crank pulley, flywheel, clutch, axles, rotors, wheels, tires . . .

Just make EVERYTHING out of carbon fiber!

[tg1_in_france]

So what kind of budget and possible torque (and consequent power) gains am I looking at on an H22a if I-:

a) upgrade the Intake, Header, exhaust and engine management.

b) As above, plus cams, forged pistons (including resleeving), valves and springs. (I guess increasing the compression ratio won't cost much more at this stage)

c) increasing the bore to make 2.4 litres?

I appreciate that there is a whole pile of dyno time needed to make any of the above work, but a ruff estimation would help.

Daemione, how would you go about maintaining the torque up the rev band?

TG1

[tg1_in_france]

Plus, can anyone explain the difference between a closed deck and open deck?

H22a1 (closed deck, OBDI). The 5th gen Preludes have the H22a4 (open deck, FRM sleeves, OBDII)

Thanx, I know I'm a thicky but I is learning.

TG1

[Daemione]

Sounds like you're doing your homework . . . . I'll talk about this stuff in a few different responses.

Originally posted by tg1_in_france
So what kind of budget and possible torque (and consequent power) gains am I looking at on an H22a if I-:

a) upgrade the Intake, Header, exhaust and engine management.

Intake & exhaust are pretty straightforward - as long as they're a constant diameter, mandrel bent, & straight through, they're basically all the same. You'll just pay more for craftsmanship, fitment, & name recognition. Price for the two of them can range anywhere from $300 (for a eBay cold air & cheap custom exhaust combo), and $1,300 (for an AEM cold air & Mugen exhaust).

Personally, I'd try & split the difference by using a cheapo short ram intake w/ custom cold air box & ducting. There's a couple fellas on www.preludeonline.com who just put together some pretty trick setups for very little cash. Then do a relatively expensive custom exhaust. Mandrel bends, 22" & 12" resonator, Magnaflow muffler . . . . Lead into it with a 2.5" Carsound high-flow cat. If you didn't mind it being a little louder, you could cut out one (or both) of the resonators to save money.

For the header, options are pretty limited for the H22. Ones like the DC Sports are inexpensive ($350-400) are basically polished up versions of the stock manifold with negligible gains. On the other extreme, the SMSP header ($1,200) will provide ridiculous gains - preliminary dynos are showing gains previously unheard of on an H22 . . . . (like 10-15 ft/lbs. of torque across the board). Of course, ones like that relocate the merge collector which means custom exhaust & cat fitment.

Of course, the above breather bolt-ons will all be subject to Attack fitment . . . . But that may be good news in the header department, as there are a couple of good options being used by the H22/Civic hybrid folks (there's more clearance on the front of the engine in those swaps than on the Prelude). AN-R & Headertech come to mind - you should be able to find information on both on the honda-tech boards. Unfortunately, not a lot of objective dyno comparisons yet.

For engine management, there are two good options right now (IMO) - Hondata & AEM. It's been a while since I've compared the two cost-wise, but last I checked the expenses worked out to be roughly the same when all was said & done. I would personally favor going the Hondata route, as reputable tuners for the system are more widespread - and there's excellent product support from the company itself. I would guess anywhere from $800-$1,200 to get it all set up & tuned. www.hondata.com & http://www.aempower.com/product_ems.asp for more information . . . . Another to look into is the EFI PMS, but I honestly know very little about it.

Re: open & closed deck H22's - try a quick search on this board. It's been discussed a couple times, I think with pictures & everything.

[Daemione]

Originally posted by tg1_in_france
So what kind of budget and possible torque (and consequent power) gains am I looking at on an H22a if I-:

b) As above, plus cams, forged pistons (including resleeving), valves and springs. (I guess increasing the compression ratio won't cost much more at this stage)

c) increasing the bore to make 2.4 litres?

The right cams & valvetrain will go a long way to building torque higher in the powerband. The stock cam profiles are kind of bizarre in that the high-rpm profile seems to peak right at the VTEC crossover . . . . moving that peak on the hot cam up 1,000 rpms or so makes for a very enjoyable torque curve, as well as some extra room on top of the redline that lets you upgrade the gearing without having to shift too often.

Brands of camshafts for the H22 include Crower, Skunk2, & JUN. They tend to organize their cams in "stages" - some of which are roughly comparable to other manufacturer's stages (crower & JUN). Others are not (skunk2). Look to spend at least $800 for cams & valvetrain upgrades.

Cam selection is complicated on VTEC engines, because you have 2 separate profiles to play with at once - some manufacturers choose to leave the low-rpm cam stock while hopping up the big one, which if not tuned properly will leave an unfortunate hole in the middle of the powerband. A frustrating engine to drive.

And once you move into the realm of upgrading cams, you will need some sort of programmable fuel & ignition tuning to realize their benefits. Piggy-back tuners like the Apex'i V-AFC are okay at adjusting fuel curves for bolt-ons, but ignition tuning becomes a lot more critical when playing with cams.

On cams with more overlap than stock, increasing the compression ratio will also be necessary for them to make their power. 11:1 at a minimum, but 12:1 or even 12.5:1 would be better. With good ignition tuning, forged pistons, & aggressive cams, 12:1 static CR will be no problem on pump gas. With competent headwork & combustion chamber reshaping, a 13:1 is even feasible. Just don't expect to ever get away with putting 87 octane in . . . . .

For pistons & resleeving, labor costs become your biggest enemy. Even for an avid & capable DIY'er, the tools necessary to do that sort of work become more expensive than just sending it out. And machining obviously can't/shouldn't be done by a shadetree mechanic. The trick is finding someone you trust to do it.

Getting the block resleeved by someone like Golden Eagle is a fairly reasonable $850-900 expense - but you have to add in pulling the engine, stripping it down, & shipping it across the country. But they'll also do lower-end assembly, which is nice. So you can send out your bare block & whatever pistons & rods you choose, and a little while later get your entire bottom end back ready to put back in the car. And you can be assured that the hone procedure was done correctly, bearings were properly spec'd, etc.

As for boring it out, the absolute limit on the H22 is 91mm (up from 87mm), which brings the total displacement to 2,360 cc's. However, you won't find anyone who will recommend taking that much out of an engine with any designs of streetability - the cylinder wall thickness is so small head-gasket sealing becomes a serious issue. Even at 90mm people have had problems. So given an 89mm bore, we're looking at 2,257 cc's - just about .1 liters bigger than stock.

To reach a goal of 2.4 liters with a streetable bore, you'd need to look into a stroker - the H23 crank & rods would get you there (95mm vs. 90.7mm on the H22). But increasing the stroke isn't going to do anything in the way of improving revability or reliability. You'll have faster piston speeds, less dwell time at TDC, more side-loading on the cylinder walls, & you'll have to eliminate the oil squirters on the underside of the pistons to fit the bigger crank. The extra displacement sure is tempting, but I'm not a big fan of increasing the stroke on the H22, it's long enough as is.

Of course, once you bore out the engine, you're looking at more headwork . . . . With larger cylinders & their desire for more air, suddenly your head is no longer going to be able to keep up at the higher rpms. Big(ger) cams are a good first step. But intake manifold porting & headwork will see good benefits on a stock motor - so if the bore has been increased at all, the need will be even more. At a minimum, it's a good idea to port match the intake manifold & head, as well as deshrouding your combustion chambers (since they're now 2mm small than the block). For more serious headwork & valve jobs, I really like the Alaniz approach - www.alaniztechnologies.com. Other options with a good reputation are Portflow & DPR. Look to spend $1,000 to start, more if you're going for lightweight valves or anything like that.

Without a doubt, good headwork & cam selection will be the best thing you can do to build/maintain torque once you get past 6,000 rpms. Just be sure to complement the change in the powerband with more aggressive gearing, or all those horsepower gains are pointless.

EDIT: yikes - that got longer than I thought.

[tg1_in_france]

Sorry to resurrect an old thread, but I though I might as well keep my little questions all grouped together.

I saw this pic of an S2000 with individual throttle bodies on Honda-tech. Apart from looking cool I guess they also help to increase power by increasing the volume of air and the ease that it can enter the head. My question is this, what are the drawbacks to this kind of set up? Is it still streetable or is it something that should be done on race only engines? I guess you have to find some way of routing cool air to them. Pointless having them gulping hot air. How does it affect the power band? If I did this to my H22 then it would only be a finishing touch after I’d reworked the whole engine.

Any advice will be greatly appreciated.

Ben

[Daemione]

ITB's (individual throttle bodies) are only streetable by the loosest definition of the word. While they're capable of making absolutely unbelievable power, they're notoriously difficult to tune - stand-alone fuel/ignition management is a must, with countless hours of dyno & street tuning. Depending on their lengths & diameters, a good idle is sometimes impossible at anything under 2,000 rpms or so, and their powerband is usually very peaky as well.

And there are obvious logistical difficulties with them in the filtration department . . . . I've seen setups with a large panel filtered airbox surrounding them, but space is usually a premium which means the design compromises their efficiency.

And, of course, they're phenomenally loud.

[Flexer]

Here is a question for you. Everyone says that if you go for forced induction on the H22 that it might be better to use the longer geared accord tranny. What do you guys know about this being a good idea? I can see how this would be better because you have the power for the longer gears, but also might it be better anyway to use the accord tranny because with the lightness of the attack you will not need all that low gearing to get some go juice. Of corse you really don't have the go juice untill the v-tec comes online, so maybe its better to have the lower gears to get you to the v-tec faster? Any comments or thoughts on this one?

[Daemione]

Yeah, that's tricky, there are lots of variables to consider - the shape of your new torque curve, how much turbo lag you end up with, whether or not wheelspin is a problem.

I'm of the general opinion that unless you're having unresolvable problems hooking up through like the first 3 gears (or have some truly awful turbo lag), the tighter H22 gears are almost always going to be better.

After all, in the vast majority of applications you're still going to have an engine that makes it's peak power at the high end of it's power-band, so gearing that better takes advantage of that is going to make for a quicker car (assuming you can keep the tires in check).

Of course, on a roots supercharger application (like a jackson racing setup), your torque curve often becomes so broad that the longer gears may be more desirable. And low-end torque increases so much that wheelspin on the launch is more a concern - although that should be less of a problem on a MR car like the Attack.

So it's hard to say - the only way to know for sure would be by looking at a dyno plot of the individual engine in question, and then plotting out the torque multiplications & potential shift points for the first 4 gears of each gearset you're considering.