Dyno graph of both maps cleaned up of plm in green vs red hytech


Trying to find an appropriate header to go with my set up, plm made 239 with better curve than the hytech shown in attached pictures, same tuner and weather was taken out of the equation by dyno program. I'm at a brick wall and about to sell this now junk expensive header. Any header suggestions or overall advice is appreciated as my goal is 250whp before March's Ifo.

Set up:
85x89 12.5:1
Stock itr head
Pro2 with valve train
Ported edelbrock Victor x with 70mm throttle body
Redline is 9k to play it safe.

 

What fuel is the motor on? Open header? I am looking for 250-260 whp on my B20V build as well. And not that it matters but if you correct the dyno numbers to STD correction they will drop slightly. Good results for a stock port head tho! I will probably be running a stock cast head too.

 

Pump 93 with full 3 inch aluminum axle back

 

Picture of said set up

 

I don't know how your fuel system is set up but just by switching over to pump E85 I usually always see a 9-11 Whp gain in the curve regardless of engine bolt-ons. Dropping the exhaust and retuning could get you another 2-5 Whp. And bam, there's your 250. And another side note, if you kept revving to 9200-9300 rpm, it looks like you might gain a few more ponies. The power curve still seems to be climbing a bit. Good luck on your quest.

 

The car is set up to compete in AMS and unfortunately being in the south we are behind in times and the nearest e85 station is inconsistent and only reads e70 most the time and is an hour drive from where I live.

 

I second the easy fix with e85. Or better fuel delivery system

Also mild porting or match porting the head to intake and exhaust could help

Yeah I had a bisimoto header and went with something more generic header and gained 7-10 whp. Over a expensive header. Greattt

But those are my 2 cents

 

Fuel system is walboro 255, full stainless lines, golden eagle rail, and rdx injectors.
If I dont find more information soon, I might try the PLM big tube, unfortunately I dont really know what would work best for my set up. I just know the small tube generic PLM tri y made 239whp

 

Did you try adjusting fuel rich to lean on the dyno to see if you could improve, also did you change the cam gear settings to see if there was any power in it. I know it lost by why, maybe there is a small change that needs to be made to benefit from the larger tube header. I don't think there is such thing as too big of a header, if you really think the exhaust is hurting it, try a converter on it or a smaller exhaust system.

 

The cam gears were degreed with motor on assembly, these same adjustments were used on this exact same motor and exact same header and made 245whp. Only difference in my set up to previous owners is his dsm 440 s to my rdx injectors, tuner, and his 68mm tb to my 70, also an ati full race balancer. Using his map and just correcting injector size, the car still map less power. Kind of scratching my head. We know the plm with my tuner for a fact put down 237-239whp about a year ago. Since the car has about 3500 more miles on it.

 

Have you tried increasing the fuel pressure from around38-40psi up to 55-60 to push the rdx's from the stock 410cc to somewhere in the 500cc range?

 

Put it on a dynopak

Ethanol will give you a small but noticeable increase, probably 2-5% increase would be my guess. 5% on the extreme end.
Another thing is the intake. Are you running one out the headlight w/ a velocity stack? I have seen good increases by making that change as well. The longer intake seems benefit the bigger motors.

Our motors are VERY similar, except I am on E85, the motor isn't degreed, and I have a SSR header. My numbers also came off a dynodynamics (the heartbreaker) lol.

I am on the quest for 250 as well. I am most likely going to degree the motor, possibly port the head and throw some flat faced valves in it to bump the compression a hair. I will most likely tune on C85 instead of pump E85. I ultimately want to see 250-260.

You have all the fixins to get 250, it's just a matter of tweaking until you get there. All the small details add up.

 

I have a headlight intake, it made very little effect on the dyno

 

Does your intake attach to that though?
If it's just a hole that provides air to the engine bay I wouldn't expect much either. Adding length to the intake is what I'm referring to.
Mine is a 3.5" tapered to a 3"

 

Yes it attaches, it just made the car run rich I guess from lack of velocity on the dyno, we accounted for it and it made little difference in curve and peak. I like that header a lot. I'm fixing to do a leakdown and compression test today after work. Previous owner says his tuner would make it break 250 easy, if everything checks out with motor, debating on seeing that statement for itself. His tuner is reputable and works for UP-REV a Nissan tuning program primarily but has very deep roots in Hondas.

 

Unfortunately, nearest e85 station is about an hour away and inconsistent. I don't drive the car very much and with ethanol it would clog or freeze the injectors. I'm lucky if I start it three times a week.

 

No, its not calling for any fuel changes that would push the injectors.

 

Perhaps higher fuel pressure would improve the spray pattern and give you a better more complete burn (more power)?

Do you think you are limited by your fuel octane? Is your tuner reaching MBT before seeing knock? If so, Ive been reading about this stuff called "race gas", its an additive that increases octane. RACE GAS | Racing Fuel Concentrate

 

Race gas isn't an option, this is a street car. We never tried increasing pressure

 

RDX injectors seem to perform best @ 55-60psi base

 

Will have to see where I'm at next time I'm around my car, just did a compression test and everything read 210+ dry, was trying to figure out if I can compare it to compression ratio and see if its what it should be and there is none.

1.225 2.215 3.230 4.220

 

For comparison my motor was 270-280 and its got ITR reps and a GSR head (calculator says 12.3:1 ish. May be a little higher since the head and block was resurfaced.

 

Yeah, I'll have to ask around to see what that's all about. Was your test dry or wet? mine was dry.

 

Someone posted something not too long ago that suggested a smaller throttle body would actually help HP. I suspect something about more velocity.

If thats the only other change, there might be some truth to his claim.
Up your base fuel pressure first, and if your still missing some ponies, try the smaller 68mm throttle body. Just because its bigger doesn't mean its better. The dyno is the ultimate decision maker as to what works and what doesn't.

Id also look into tweaking the cams a little to see if you can hit 250, however the shape of the powerband might suffer and you may actually be slower. Just because the cams are degreed, doesn't really equate to the best setting, does it?

250....almost.... there....

 

Mine was dry. I tested it after first start to make sure all the rings were seating up right.