Ok finally I got my new rings and bearings broken in enough that I felt ok to go with a WOT dyno run at our local dyno here in Vancouver during the last ITRBC club meet.

My mods to the engine so far are: Mugen CAI, taper bored TB, stock intake, cleaned up cylinder head, Toda B cams and upgraded valvetrain, Endyn RW pistons, Eagle rods, balanced crank, Spoon flywheel, 4-2-1 header and straight pipe and Mugen B-pipe/twin loop. I run stock injectors, stock timing (on the conservative side for now), and an OMP rising rate FPR.

The ECU is a remapped Mugen N1 (Yoshio tuned) with adapter harness from King. Vtec xover is at 6800 rpm and fuel cutoff is 9300.

The car pulls strong and doesn't ping at all. I use 94 Chevron gas. It still seems to be running rich but I haven't done any wideband 02 readings (unavailable at the time)

Here's the dyno plot:



The shop didn't enter my current mods so I whited out the mod list that was on there (i know....looks like ***).

My questions to you guys are:

1) What determines whether or not larger injectors are mandated? It's pretty hard to monitor injector duty cycle with the facilities available to me. As I said the car seems to be running rich and I'm not running huge fuel pressure yet (idle is 40 psi - max is about 55 psi). I know a few guys have run 310 cc/min injectors or larger. What made you do this? Pinging? Lack of top end power?

2) I'm planning to upgrade the stock ignition coil to something better (probably Nology since I already have their wires). Will this likely improve combustion or is it a waste of money? Do you think it will run leaner/make more power by providing a larger spark?

3) Do you think my current exhaust is a limiting factor? Should I consider a true 2.5" system? I was thinking this would be my next upgrade....

4) What do you think is causing the leveling off of hp at the high rpms? is it air induction? Should I get a larger TB? Or do you think I need more fuel up top? (yes I know wideband 02 readings will be helpful - but I'm only looking for opinions here)

Any and all opinions would be appreciated...TIA.

BPR

 

WIth spec B cams and a cleaned up head, you should (almost NEED) a 2.5" exhuast..i think it would put you over 200WHP..nice *** graph.

 

You should try lowering the VTEC and adding fuel in the midrange.
I'm telling you.. that dyno plot of yours is a dead ringer for my friend's. Only difference is he was stock throttle body, Mugen 4-1 header and hot air intake.

His peak numbers were 194.6 and 138.0..
His VTEC was 5900 I believe. It was set at 6600 before the dyno and if I remember correctly, after tuning fuel, we gained about 4-5hp between 5700-6600 area where VTEC was not engaged previously.

 

I had to upgrade my injectors (my set-up is a slightly more extreme version of yours, with a fully ported/polished head, knife-edged crank and balanced bottom end, Spec B's and Toda 12.4:1 compression pistons, Hondata ecu, Spoon header, 2.5'' custom exhaust, etc.) because I was leaning out at the top end even when pushing the stock injectors to their absolute maximum duty cycle via ecu tuning. I just couldn't get enough full over 7,000rpm so I upgraded to Toyota 440cc, turned down the fuel pressure to get the injectors duty cycle at a comfortable rate and easily had enough fuel at the top end to avoid a lean condition.

I'm really no expert (had a ecu tuner at the dyno dealing with all this for me), but as I understand it if you're leaning out at all and you can no longer compensate by adding more fuel via the ecu because your injector duty cycle is maxed out, it's time to upgrade your injectors.

I have my VTEC xover point at 6200rpm and that completely eliminated that little blip you have in your plot at around 6800rpm. Gave me a bit more area under the curve as a result.

Hope this helps,
Dave


[Modified by Maxi, 9:21 PM 11/15/2001]

 

i was having trouble getting over the 200whp mark..finally after uncorking the twimloop..hp levels rised dramatically...

 

"I use 94 Chevron gas"

Dang, I wish I had that stuff here in CA! I'm stuck with premium Chevron 91 octaine!!!!

 

EP - you are at 200whp? I didnt know Mugen made cams

 

stock cams baby!

 

Maybe you have one of those abnormally strong ITRs (like mine) - but I thought the strong ones only came in yella!

 

Through the A'PEXi PowerFC I was seeing the stock injectors hitting 100% duty cycle, I upgraded them to RC 310 cc/min...then while at the EXPO I noticed that the Injectors had hit a peak of 98% duty cycle...Now I have RC 440 cc/min, they are only peaking out at around 65%. The drop off up top may be due to how you have the cam gears adjusted...or your header cannot flow enough air at those rpms, btw which header do you have, you just stated that you had a 4-2-1 header. The larger 2.5" exhaust piping will be helpful to you, as it is a restriction, which might also be the reason the curve is leveling off at the top.

Nice plot...I'll have to compare it to mine when I get back to work tomorrow.
Austin

 

Hey Mike K that guy in your Avatar is like some big **** star isnt it? LOL

 

what CR r u running

 

The header is Spoon. The CR is 12.5:1. Stock head gasket too.

I could only get 188 whp out of stock cams. I gave up. I'm thinking Toda C's now and a bigger bore exhaust system.

 

Question: If you don't have a Hondata or Power FC how do you determine if your maxing out injector duty. I have a pretty extreme setup now. and i'm still running stock injectors.

 

comptechgsr,

since your post was technically in response to mine, I'll respond. I am running stock compression, havent messed with the car too much.

 

Hey Big Phat R... Maybe you should start with an 01 R..heh heh

( You were just waiting for that wern't you? )

I'd give you advise but I haven't got a clue... If you switch to Webers.... I'm your

man...

 

I ran a 2" under axel exhaust and I made 208.7hp @ wheels so I think its not just the piping size, I think you should consider some exhaust which has higher efficiency.

310cc injectors??? You won't need them if you run over 210hp at wheels then you should get them. The ITR injectors will max out over 210hp.

As I see there is a dip during 6700rpm (vtec change over), if you can adhjust your vtec point at 6000rpm then the problem should go away.

I ran the following setup to make 208.7 at wheels :

Spoon A-spec cams IN300 EX288
Spoon header
Spoon valvetrain
Spoon rockers
Spoon test pipe
AJR Intake
AJR Head Work
AJR TB (tapered)
AJR Pistons (supplied by Endyn) CR 12.2:1
AJR tuned ECU
2" underaxel exhaust
-stock injectors & regulator

I wished to post my dynoplot but I am too stupid cuz I dont know how to use the scanner . Well, I will post it the plot in these couple days.

 

Judging from the plot...I think perhaps you need better control over your ECU....something like hondata or AEM perhaps? (Anybody got more info here about the AEM?) It was too bad you erased the OG N1 program on the Mugen, it woulda been something that could fetch you good money I presume.....A P28 or P30 Hondata woulda been anothe viable option.....since you could make changes almost on the fly. I personally believe that Yoshio is a great tuner...but he can't do **** when he's like 3000+kms away...where parameters like weather etc...and the fact every car is diff. is totally out of his control... I think he's just making the best educated guess he's got with the info you can provide him.

From what Hondata has stated on their site, they have found that many of the Hondas operate at around or over 80% of the duty cycle. Apparently, it works great with stock to mild mods but far from good since the majority if not ALL successful Toda B powermakers out there have used at least 310 and up...maybe they are on the right track....hehe

Can't say much about the exhaust..but that woulda been my next guess..solely because the bpipe leading to the HUGE *** resonator is only 2inches in diameter before it gets up to 2.5inch or so.....probably good for stock ITR cams and maybe even a mild Spoon/Spec A cam but probably not enough for the Bs.....

Nevertheless, you put out some solid numbers!! Keep at it Jon, I'm sure you will be happy with your Bs... when properly setup....!

 

****!

jus loooking at the plot is making me antsy about going back home to cali, and putting my pistons/tb/itm/tuning/ecu in...

ugh....my toda b's are lonely.....

**** man, i cant wait to get back to cali for winter break...

IT'S HP TIME

 

thats always the case isn't it? never enough

 

Yeah, it's my man Ron Jeremy.

 

I heard there is some kind of documentary/movie/something coming out on the man

 

EP, exactly what did you do to 'uncork the twinloop'. I was looking into getting this exhaust but didn't like that it was only 2.25" for the the USDM one from King and 60mm for the JDM one. I wanted something around the size of the JDM mugen headers and Carsound cat which are 2.5".

 

hytech! John Grudinski uncorked the power potential

 

lower the x-over to 6200ish.