NA performance? Look here.

[klr142]

Interested in NON-TURBO, normally aspirated power increases? Here's a lot of info to digest if you'd like!

Most of this is about engine performance, but to have a fast normally aspirated car, you need to “add lightness” and short gearing to give you as much mechanical advantage as possible. Getting rid of that 3.31 differential in your rear end can help more than you think! Smaller diameter wheels and tires are lighter and give you better gearing as well.


LH TUNING: I also included a zipped folder attachment with bin and xdf files and the checksum tool for TunerPro if you're running LH2.4 or LH3.1 and want to do some tuning of your own! You'll need need to download TunerPro or the BOSCH LH 2.4 EDITOR in order to tune your own stuff. If you don't have an Ostrich, you can get a chip burner online and do it that way instead if wanted(Ostrich recommended!). I also included a tweaked 951 bin file and notes that I'm running on my car as of right now with a slightly shaved 530 head, .036" headgasket, 16V White-Top fuel injectors, H cam, opened airbox and exhaust mods if you want to try it out.

Here's a reference to past and current NA performance discussions with at least some decent info in each. Some of the info is older, but mostly it's good and worth reading. The earlier threads in each section are more recent(or will be when I get around to organizing).

I can also put together a bunch of dyno plots.

Squish/quench/thin headgasket/piston-head clearance discussions:
Building a tight squish motor: https://forums.turbobricks.com/showthread.php?t=110700
Shaving the head for bigger bangs: https://forums.turbobricks.com/showthread.php?t=348598
What's the thinnest Cometic you've run?: https://forums.turbobricks.com/showthread.php?t=274989
Any problems running thinner headgasket for quench?: https://forums.turbobricks.com/showthread.php?t=251784

Camshaft discussions:
MUST READ -We measured redblock cams: https://forums.turbobricks.com/showthread.php?t=337956
VX worth the cost?: https://forums.turbobricks.com/showthread.php?t=266225
A cam, B cam, IPD T cam, D cam: https://forums.turbobricks.com/showthread.php?t=150954
V vs VX: https://forums.turbobricks.com/showthread.php?t=277707
H or K: https://forums.turbobricks.com/showthread.php?t=275416
A or B: https://forums.turbobricks.com/showthread.php?t=341814
A or VX3: https://forums.turbobricks.com/showthread.php?t=342490
Effects of changing camshaft timing: https://forums.turbobricks.com/showthread.php?t=209648
RSI NA cam in action: https://forums.turbobricks.com/showthread.php?t=164071
B21 with RSI NA cam: https://forums.turbobricks.com/showthread.php?t=266267
Redblock aftermarket cam experiences: https://forums.turbobricks.com/showthread.php?t=333776

General NA performance:
NA performance goals: https://forums.turbobricks.com/showthread.php?t=354436
Emissions and NA performance: https://forums.turbobricks.com/showthread.php?t=353970
How much power can you get NA: https://forums.turbobricks.com/showthread.php?t=272196
531 worth it on NA?: https://forums.turbobricks.com/showthread.php?t=275133
Coach me on NA build: https://forums.turbobricks.com/showthread.php?t=290198
NA power: https://forums.turbobricks.com/showthread.php?t=337311
Drifts N Lifts header test(watch all the engine related videos): https://forums.turbobricks.com/showthread.php?t=342098
531 on NA auto: https://forums.turbobricks.com/showthread.php?t=342456
World Record B230 Power: https://forums.turbobricks.com/showthread.php?t=348117
LH 3.1 NA stuff: https://forums.turbobricks.com/showthread.php?t=349476
LH 3.1 NA basic build: https://forums.turbobricks.com/showthread.php?t=355121
Streetable 8V vs 16V: https://forums.turbobricks.com/showthread.php?t=347900
B21F/K-jet manifold on B230: https://forums.turbobricks.com/showthread.php?t=267011
What kind of exhaust?: https://forums.turbobricks.com/showthread.php?t=252103
Rebuilding a B21F for modest gains: https://forums.turbobricks.com/showthread.php?t=244434
General performance: https://forums.turbobricks.com/showthread.php?t=250869
General torque/performance: https://forums.turbobricks.com/showthread.php?t=245008
Camshaft selection, head height/shaving, etc.: https://forums.turbobricks.com/showthread.php?t=152983
Intake plenum: https://forums.turbobricks.com/showthread.php?t=153339
NA upgrade order: https://forums.turbobricks.com/showthread.php?t=145344
Cam choices for high compression: https://forums.turbobricks.com/showthread.php?t=140759
Stealthfti/Thomas Fritz(RIP ☹️) gallery with lots of longevity/efficiency tricks: https://pbase.com/stealthfti/root
16V/B234 upgrades(with Erland Cox!): https://forums.turbobricks.com/showthread.php?t=249791
More NA power in a nutshell(with JohnV): https://forums.turbobricks.com/showthread.php?t=337311

And there's many more, but a good start. Feel free to share other threads that you've saved.

[hessam69]

[shoestring]

I'm stoked to dig into these. Thanks Kyle!

[klr142]

Reserved for dyno plots...

[hessam69]

No turbo, just real power

There should be an NA highest HP/quarter mile competition

[740atl]

Originally Posted by hessam69

No turbo, just real power

There should be an NA highest HP/quarter mile competition

There should be a "look how much money I just spent to go this slow competition".

[klr142]

I added a zip file with a bunch of LH tuning bins and xdfs for those looking to tweak their LH2.4 8V, LH2.4 16V and LH3.1 8V NA cars to the first post! I also threw in my personal 951 bin from my 244 with a basic package on it(slight shaved head, H cam, thinner headgasket and other basic tweaks with 16V white-top injectors).

Originally Posted by hessam69

No turbo, just real power

There should be an NA highest HP/quarter mile competition

It's more fun to beat the slow turbo cars in the EvW competition, and mostly, there's just not enough people actually getting out to the drag strip and posting about it on TB anymore.

Originally Posted by 740atl

There should be a "look how much money I just spent to go this slow competition".

Boooring.

[shoestring]

Depends on application. Sometimes turbo good, sometimes, turbo not.

[katluke]

Some good NA info/advice when I enquired about tuning the B234. hth

http://forums.turbobricks.com/showthread.php?t=249791

[KwikBrik245]

Thanks for the post!

[culberro]

Info on shorter timing belts: http://forums.turbobricks.com/showthread.php?t=235689

Square tooth, 122T: Gates T013
DODGE CHALLENGER 1978-1979
DODGE COLT 1977-1979
FORD PINTO 1971-1974
MERCURY CAPRI 1971-1974
PLYMOUTH ARROW 1977-1980
PLYMOUTH CHAMP 1979-1980
PLYMOUTH COLT 1977-1980
PLYMOUTH SAPPORO 1978-1979


Round tooth, 122T: Continental TB089
DODGE COLT VISTA 1985-1986
DODGE COLT VISTA CUSTOM 1986
DODGE RAM 50 1985-1986
MITSUBISHI CORDIA 1985-1986
MITSUBISHI MIGHTY MAX 1985-1986
MITSUBISHI TREDIA 1985-1986
PLYMOUTH COLT VISTA 1985-1986

[klr142]

Oh hi! Thanks Robert for the shorter belt info.

I should just throw some basic recipes in here for people to follow. I'll slap this here for now but will eventually add them to the first post. Here are a couple real quick and rough ones. Well, the first step is pretty much filled out and assumes you already have a good Stage 0 of no vacuum leaks, good plugs, wires, cap/rotor, all sensors functioning properly, throttle is cleaned, etc...

Cheap N/A power step 1 in no particular order(go from 60-90whp/90-110wtrq and 18-20+ second 1/4 mile times to 90-120whp/120-140wtrq and 16-18 second 1/4 mile times):
1. Tighten your valves on your current camshaft(.012-.014")! If using a D, K or H cam, you'll want to keep the clearances closer to .016" or .018" for a better/smoother idle and off idle performance because they have higher duration and overlap than all the other factory equipped cams. The tighter the valve clearances, the "larger" the camshaft becomes, but it will also pollute more and idle worse. On most of the factory cams, they'll still idle just fine, but the D, K and H in particular can be rough with tighter clearances, and it won't be ideal if you have stock compression and engine management.
2. Clean your fuel system/injectors and soak your pistons to get rid of carbon build-up, especially in the rings to restore lost compression(Seafoam, Marvel Mystery oil, "top end cleaner", Techron, etc.). Have your injectors cleaned if you'd like, or just do the Techron or similar fuel system cleaner in your tank.
3. Raise the ignition timing if on LH2.2 or earlier. You won't want to do much if running regular fuel and using the smaller or original camshaft, but you can get away with more if running the larger camshafts that have more duration such as the D, K and H in particular as they reduce the Dynamic Compression Ratio more.
4. If running an M or T cam(T cam is better, by the way!), retard the cam timing 2-4 degrees if you happen to get an adjustable gear cheap(make sure it's legit and the timing marks are accurate). If you can afford a cam swap, just about anything is an upgrade(not the L!).
5. The D, K or H cam will be a little sluggish off idle on a stock long block without custom spark and/or fuel tuning, but they'll all work fine and make reasonable power from 2000rpm on up, with more than any of the others above 3000/3500rpm or so. The K cam is the best all around factory cam. The H idles worse and may make more peak power in some circumstances, but it doesn't have as good of idle quality as the K and doesn't make that much more than the K in peak power, if any at all in some people's experiences. With these cams, if you have an adjustable cam gear, you may want to advance it 2-4 degrees to improve your low end torque in daily use.
6: Remove the hot air intake flap from the airbox and re-route the pre-heat tube to fresh air at the front of the car(in the bottom spoiler, or the other side of the radiator support on the other side of the radiator).
7. Not necessary, but if you want, you can modify the exhaust with different mufflers. Ideally, you'd upgrade to at least 2.25" piping such as the original style turbo exhaust with the single muffler in the back. Not much power to be gained here, but it'll sound better and make a little bit of difference just like everything else.

"Cheap" N/A power step 2(110-140whp/130-150wtrq and 15-16 second 1/4 mile times):
Basically, SHAVE THE HEAD .040"/1mm or more depending on camshaft choice, get your head surface closer to the piston tops and use a minimum of a B, A, V, VX, D, K or H camshaft. Ideally you'd be using something along the lines of an IPD Turbo cam, ENEM V15NA(likely almost as much peak power as the K and H camshafts, but a wider powerband with more torque), V16NA or similar offerings from other vendors. A thinner headgasket is your friend, and .030-.040" maximum piston to head clearance will improve combustion efficiency and help prevent detonation. If your bottom end is in good shape and you don't want to rev over 6,000rpm, many have gone even tighter than that(possibly some as low as .020" clearance, but you're likely pushing your luck!). Here you'll want your 2.5" exhaust starting at the factory 2-1 merge in the downpipe and continue it back. You'll want/need to look into adjusting your ignition timing and likely your fueling to dial things in providing a better powerband and keep detonation at bay. Premium fuel may be required depending on your compression and camshaft choices. Factory ignition timing can be too much advance in some circumstances. This engine can still pull very strongly from basically idle and have more power than stock starting at very low rpm(2000rpm?). It can be very efficient and great for daily use and keeping up with or even beating modern traffic depending on the rest of the setup. Works fine with lazy, 4 speed automatic transmissions.

Not cheap N/A power step 3(135-175whp/140-170wtrq):
Recommended minimum of the K-jet intake manifold for the larger diameter runners for best results, but 45mm/48mm individual throttle bodies or carbs will do even better. You can do over 140whp on the stock B230F style manifold, but it's basically at its peak and holding you back. You will want a larger diameter 2-1 downpipe for best results, but stock sized can still do over 140whp. Your K/H cam is near their limits and you ideally will be running something more modern with at least 12mm of lift, such as the Enem K13 or preferably even larger(Enem C2 is a lovely beast). You will want to look into having port work done to improve cylinder head flow, and/or the 531 cylinder head(neither are required for 135whp, but, the better the flow, the better the overall result). You can go to a properly sized 4-2-1 header if wanted, but it's not required(the General Leif has over 165whp still with a factory exhaust manifold). You will need the ability to tune your fuel and spark. Either LH2.4/3.1 with an Ostrich or custom chips, carbs, or stand-alone engine management of some sort. You will likely want at least .040"-.080" off your head. Maybe even more depending on your camshaft, piston-head clearance, cylinder head and what you do for opening up and unshrouding the valves in the combustion chamber. A fresh bottom end with good ring seal is your friend here(anywhere, but costs money), but it's not required. You do NOT NEED larger than stock valves. The General Leif is at/over 165whp with stock valves. Depending on camshaft choice and everything else, you may be able to accelerate fine from an idle, but it might not like full throttle until over 2000-3000rpm without special tuning(individual throttles can help, but aren't required).

More expensive N/A power step 4(175-200whp and similar to above peak torque):
Bigger camshaft, 2.5-3mm off a well ported head with chamber mods also recommended for unshrouding, etc.., custom intake manifold or 48-50mm carbs/ITBs, custom 4-2-1 header with 44.5mm primaries, 51mm secondaries, etc.. Custom engine management and mapping, etc.. Better valve springs to deal with the quick opening and closing of the valves with the high durations, etc.. Bigger valves aren't required but likely will be a better match at this point.

SERIOUS N/A power step 5(EVEN MORE POWER and similar peak torque):
MORE.

[klr142]

Latest and greatest regurgitated info regarding compression ratios, camshafts, valves, heads, horsepower goals, etc..
Here, here, and here.

[spock345]

I must ask, do we have threads on tuning NA OHV redblocks?

I am again working on my dynamic compression calculator spreadsheet so you can input your own engine's specs. Also going to try expanding it to cover OHV motors and their camshafts. Should be done in a few days.

[klr142]

Originally Posted by spock345

I must ask, do we have threads on tuning NA OHV redblocks?

I am again working on my dynamic compression calculator spreadsheet so you can input your own engine's specs. Also going to try expanding it to cover OHV motors and their camshafts. Should be done in a few days.

We do have some for OHV engines, but obviously not as many as OHC stuff. I have not compiled any of the pushrod stuff though, sorry!

And GREAT news on your spreadsheet! That's awesome. I'll need to include that in this thread.

[klr142]

Originally Posted by culberro

Info on shorter timing belts: http://forums.turbobricks.com/showthread.php?t=235689

Square tooth, 122T: Gates T013
DODGE CHALLENGER 1978-1979
DODGE COLT 1977-1979
FORD PINTO 1971-1974
MERCURY CAPRI 1971-1974
PLYMOUTH ARROW 1977-1980
PLYMOUTH CHAMP 1979-1980
PLYMOUTH COLT 1977-1980
PLYMOUTH SAPPORO 1978-1979


Round tooth, 122T: Continental TB089
DODGE COLT VISTA 1985-1986
DODGE COLT VISTA CUSTOM 1986
DODGE RAM 50 1985-1986
MITSUBISHI CORDIA 1985-1986
MITSUBISHI MIGHTY MAX 1985-1986
MITSUBISHI TREDIA 1985-1986
PLYMOUTH COLT VISTA 1985-1986

VAZ 2105 is supposedly another belt that will work. The MD140228 might be the Mitsubishi part number for the round tooth belt(TB089 alternate part number).

[spock345]

Dynamic compression ratio calculator. Right now working on cleaning it up and adding OHV numbers. Anyone have numbers for B18 and B20 combustion chamber sizes?

https://docs.google.com/spreadsheets...#gid=935234908

[shoestring]

Originally Posted by spock345

Dynamic compression ratio calculator. Right now working on cleaning it up and adding OHV numbers. Anyone have numbers for B18 and B20 combustion chamber sizes?

https://docs.google.com/spreadsheets...#gid=935234908

Finally got to looking at this a few days ago. I have a question, how did you figure the intake closing point? I measured a lot later valve closing event, which would provide a lower DCR than shown. I'm not challenging you, looking to maybe learn something.

[spock345]

Originally Posted by shoestring

Finally got to looking at this a few days ago. I have a question, how did you figure the intake closing point? I measured a lot later valve closing event, which would provide a lower DCR than shown. I'm not challenging you, looking to maybe learn something.

There is a way to calculate the approximate intake closing point based on the LSA and intake duration. I forget why I did that on the chart that uses your cam specs. It is easy enough to change.

The formula is (intake duration/2) + LSA - (advance + 180).

[shoestring]

Gotcha.

I wish there were a serious engine builder on here that could weigh in. I miss JohnV. I'm just a home mechanic with a really healthy curiosity on how this stuff works but without the resources to devote to get really smart.

[culberro]

For DCR calculators to be close enough to use, I'd go for measured intake valve closing. Or calculate it, then go for +/- 5+deg from that to give you a range.
DCR and SCR calculations are just one tool you can use for performance engine building.
The most important thing to do is measure what you have, don't take what someone else has done as truth. Use someone else's measurements to get an idea what's going on, but don't count on them for your
final calcs.

[spock345]

Originally Posted by culberro

For DCR calculators to be close enough to use, I'd go for measured intake valve closing. Or calculate it, then go for +/- 5+deg from that to give you a range.
DCR and SCR calculations are just one tool you can use for performance engine building.
The most important thing to do is measure what you have, don't take what someone else has done as truth. Use someone else's measurements to get an idea what's going on, but don't count on them for your
final calcs.

I agree, each motor is going to be a bit different. I intend for this tool to be useful for "back of the napkin" math that lets people pick a direction to go in and make a plan.

[culberro]

I think it's a great tool for that as well!
The tools needed to do all of these measurements yourself are not expensive ($50?), and it's cool that someone can use measured values.
The "Advertised cam specs" that are listed on the forum are questionable, but it's cool that you included them!

[shoestring]

Originally Posted by culberro

The "Advertised cam specs" that are listed on the forum are questionable, but it's cool that you included them!

Agreed. Even mine could certainly be found to be a little dubious, as the graduation on my dial indicator is 0.001". One thousandth, on an opening or closing ramp, can be several degrees. The only solace I have is that my numbers came out really similar to the guy who did the listing for Calgary Volvo Club. Cam and I have tried to figure out what valve event points the overseas manufacturers use to measure their duration figures. Despite trying a few times with a couple different cams, we really couldn't come up with an answer. The closest we came up with is that it's something like 0.5mm lift AFTER lash, which we have no confidence in. They do seem to be much longer than other sticks when using SBE (Society of Backyard Engineers) standards.


One thing you have to be careful about when calculating your valve events is that you're assuming a symmetrical lobe (opening and closing ramps are shaped identically), which is seldom the case.