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Got my ITBs running well, what's next??

Tentshedtrev

Tentshedtrev

Member
Joined
May 6, 2016
Location
Vancouver Island, Canada
Ok, small backstory first...
I did a small build thread a while back, Yamaha R1 itbs running SDS, switched to Megasquirt, sounded good, drove like junk except wot.
Fast forward a year or so, I sourced ITBs from a Toyota 4age 20v, made a completely new manifold, and studied setting up the blended speed density/aplha-n itb mode in MS2extra until my head wanted to explode....
After many issues, some of which were mechanical, some of which were electrical(bad grounds, weak fuel pump, bad bip373 ignition driver, wrong ignition offset cauing timing to max at 19*, bad db9 connector...how did it not burn this car again?!?) We finally got it sorted!
Set base maps, got a good idle, set up my itb load switch points, afrs dialed, closed loop nice a lean for cruise (milage is about stock) 12.7 under wot, accel enrich almost perfect, waiting on a new laptop battery as mine died....
Car pulls hard! Nice increase over stock, sounds absolutely fantastic, driveability is almost oem with the lovely progressive throttle linkage Toyota designed....but......I need more...
Specs are:
Stock b230
Stahl 4-1 header...small primary one I think? (Not good right?)
4age silver top ITBs, custom intake, (38mm ID, to match the itbs, runners are about 7" total length)
Technotoy 40mm velocity stacks
Bosch 24lb injectors
Megasquirt ms2extra, ITB mode, direct coil control, stock dizzy, stock coil, stock hall sensor pickup.
K cam
Mobil 10-40 synthetic
B21ft oil cooler (was free, why not)
M46 trans, fresh stock clutch and pp
3.73 gears.

Car is a street car, 1983 245, the odd autocross, but mostly just a platform to experiment on and enjoy every chance I have, HP is nice, but it's just a number, strong mid-range is what I'm after, the long intake runners seem to have already helped significantly, as I researched they would.

Where do I go from here? My plan was always to get the management properly sorted on a stock mill, (seemed like a dumb idea to invest money in heads, cams, cams and pistons only to risk leaning it out or rattling the ringlands out of it...lol)
Many people say deck .40, port, big valves, kg8 cam, and a 4-2-1 header and have fun, am I overthinking things and just need to spend some money? Or is there a better way to modify this 8v? I'm not a mechanic, this is a fun hobby I do in my spare time. Many people on here smarter than me. I understand the basics, airflow and compression = power for NA, but when it comes to parts lists and build threads for NA cars, I'm buried in a bunch of conflicting information and dead ends when I search!

Oh, one last thing, before people say double the # of valves and be done with the tractor head....no. I hate the way they sound...that's it, don't have any other reason...silly reason for making my life difficult? Yep. Sorry? Nup...

Thanks, apologize for the essay.
 
Spray it with a controller set up to boost mainly the midrange?
I know ms2extra should handle the ignition OK, but you may need a separate NOS controller.
 
I'd be pondering a lighter flywheel too, just for the feel. Spinning a chunk of heavy stock flywheel up to higher RPM's takes time and power. It's not necessarily something that would affect peak HP, but it's very noticeable in driving.

But yea, cam and headwork. The custom cams and headwork is where you get into paying $$$$ for an 8V that flows as much air as an unaltered boneyard 16V head.
 
If you don't do a lot of freeway driving with it, maybe think of lower gears, 4.10 ring and pinion really wakes things up, especially if you have raised the rev limit with MS.
 
brian smith said:
Spray it with a controller set up to boost mainly the midrange?
Click to expand...

Oddly enough I have in my possession a direct port nitrous injection wet setup from my friends dirt drag zx6, I have enough spare outputs in MS to run it, but I feel like some of the mods needed to make a healthy nitrous engine would make it a bit of a dog off the bottle...than, and having to refill. Not a bad idea, and I have considered it!
 
Mueller said:
I like the idea of bigger cam and higher compression.

Willing to share the msq file for the MS? :)
Click to expand...

It's all yours if you want it, I will be the first to tell you I'm no tuner tho! Biggest thing that helped me was downloading megalog viewer HD, and writing a custom filter to only see data when the engine was above 88kpa and below 92kpa. That is where I set the itb switchover point (thank Andy Whittle from the MS forums for that one!) Using that collected data, I could see at what TPS position I hit those kpa's....it's very low! from 6% to about 18% tps I can experience almost 0 vacuum, as per what everyone says about individual throttle bodies, and why pure speed density doesn't work haha..

(Yes I have a vacuum box and a 0.30 mig welder tip in the map sensor line too!)
 
Headwork made my 82 turbo run better at all rpms. I kept the valve sizes stock and just had the head flowed and optimized for a fun street car. The head work and a cam really made the engine run great.
 
classicswede said:
Cam and head work is where you are at
Click to expand...

Porting heads is out of my current experience zone, I do have a few heads to practice on, mostly 530s, and a few VW friends that have done some amazing things with their 8v heads. The stage 4 cam on your website has me interested, how does is stack up to say a kg8? I feel like even an H is not going to be after the sort of gains I am after, and I'm ok with choosing an aftermarket option.
 
The KG8 has a little more duration and lift but the lobe centre line angle is tighter. The T4 is going to be better low down and mid range. The KG8 is going to make more power in the higher RPM's and would be the better choice as a motorsport cam.

The H is still a mild cam as far as cams go in Europe, its only on TB that you get comments saying it is lumpy and a aggressive cam
 
So a t4 with say a 4-2-1 header would be a good grunty street combo?, and if I am sticking with the Stahl 4-1 header the kg8 is more in complimenting those high rpm characteristics? More and more I am thinking of selling that Stahl header and finding a decent 4-2-1....anyone want to trade?
 
Tentshedtrev said:
Oddly enough I have in my possession a direct port nitrous injection wet setup from my friends dirt drag zx6, I have enough spare outputs in MS to run it, but I feel like some of the mods needed to make a healthy nitrous engine would make it a bit of a dog off the bottle...than, and having to refill. Not a bad idea, and I have considered it!
Click to expand...
Improve the areas you are looking at in this thread. Header, cam, head work. Also look into a lightened flywheel and stronger clutch. In the meantime put a little juice to it. Direct port would be nice and easily controllable. 60hp of nitrous would really wake it up when you needed/wanted it and be completely reliable with touching anything. You can probably reliably feed more to it, just depends how safe or how far you want to push it.

I ran a single fogger wet kit with "50hp" jets on my shaved head 200k mile b230f junkyard motor. I beat the **** out of that motor and it just seemed to love it. I held it floored for a full bottles worth of nitrous a few times. Never missed a beat.
 
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