***SETUP HAS CHANGED, READ THROUGH TO MY JULY 4TH POST!***

Hey guys, I know this topic has been covered over and over again, but the search didn't yield any information for my specific plans. This build will consist of a d16y7 block and an obd2 d15b 3 stage VTEC head. I will be using z6 intake manifold, and distributer (hopefully) and running the whole setup obd1 and eventually on crome. I will be changing out the pistons in favor of a little bit more compression, and to have a fresh setup. I have read that the d16a1 pistons do over 11:1 in a d15b block, should that be similar in this one? Are there better choices? What timing belt should I use, and do I need an adjustable cam gear? Head bolts? The overall goal of this build is going to be 55mpg and 200whp on the bottle on regular unleaded. I know this sounds a little bit crazy, but I think It will work if I use a meth kit to come on during VTEC, and use a wet nitrous kit. As far as tuning goes, I was going to use an rpm switch to actuate 16 valve mode at 3krpm like stock, but now im thinking I can just wire the two solenoids together and have it kick 16valve and VTEC at the same time so I can rock 12 valve and kick *** MPG when im not beating it's ***. Also this allows me to go with like a 1mm oversize intake valve, yes only 1... well 4 actually, the ones that become engaged in 16valve mode, so that will be another good power mod that will not affect the fuel economy out of VTEC. Also, I am looking for a cam that is aggressive in VTEC, but stock otherwise, and will an aftermarket y8 cam even work in this head? Sorry for the big jumbled thought, thats how it goes through my head, and please don't flame me... THIS IS GOING TO WORK one way or another, I promise! Yes I know the actual power curve is going to look shitty, and I know that VTEC crossover is going to be jarring to say the least, but that is what I am looking for. I want this thing to behave like a CX all the way up to 4800 and then I want Type R!

Thanks in advance for advice and input!


Modified by oneludesol at 12:32 AM 6/12/2007


Modified by oneludesol at 1:08 AM 6/12/2007


Modified by oneludesol at 12:32 AM 7/4/2007

 

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i wouldn't even worry about building the engine if i were you. i would get oem parts, get a fresh rebuild and just tune to 200whp on nitrous.

 

damn 55mpg and 200 hp if this works ill pay u to build me one

 

well, the rebuild was going to be stock honda parts, but from what motor should I use, and what CR should I be shooting for?

 

btw, 55mpg is insanely high. 40 is the best you could hope for cruising at 60mph on a flat surface.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Nongan &raquo;</TD></TR><TR><TD CLASS="quote">btw, 55mpg is insanely high. 40 is the best you could hope for cruising at 60mph on a flat surface.</TD></TR></TABLE>

no its not, 3 stage d15b in a rex i have heard of doing 65mpg. vtec-e's do 55mpg or better and this motor is basically a hybrid between a z1 and a y8... If I keep it under 3k rpm and tune for 20:1 afr's (in 12 valve mode, 3k and under) I bet I will see better than 55mpg at 70mph.

 

20:1 thats nuts im very intrested in seeing how this works out.

 

VTEC-E's run between 20:1 and 24:1 in "lean burn mode" which is before 3k rpm, less than half throttle, and 12 valves. Im just trying to copy a proven concept. thanks for reply!

 

My 92 cx got 42 mpg on non-flat surfaces and it had alot of miles on it so high 40's low 50's would be attainable.

 

Today I got my 3 stage head!

 

nice, this should be a pretty crazy grocery getter

you're going to use methanol injection? i've never heard of doing that on a n/a setup, where'd that idea come from?

nothing wrong with defying convention though

 

***NEW SETUP IDEA***

After thinking long and hard about my plans for this motor, I have decided to go another direction. The MPG and WHP goals are the same, however the new build is going to be vitara and turbo. I decided this because it dawned on me how much of a bitch it will be to tune 24:1 afr's with 11:1 compression. This way with 8.5:1 it will be much easier to tune the first stage nice and lean. Next to change is the actual crossovers. I started using ECtune on the Del Sol and found that with the general outputs, I will be able to "imitate" the actual ecu for this motor with stage 1 (12 valve mode & 24:1 afr) ending at 3k rpm or 50% throttle position. Stage 2 will be tuned normally for boost as well as stage 3, VTEC. (rather than having stages 2 and 3 engage at the same time).


Modified by oneludesol at 12:33 AM 7/4/2007

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ev13lf &raquo;</TD></TR><TR><TD CLASS="quote">nice, this should be a pretty crazy grocery getter

you're going to use methanol injection? i've never heard of doing that on a n/a setup, where'd that idea come from?

nothing wrong with defying convention though</TD></TR></TABLE>

It was more an off the wall "it's gotta work" idea, I just figured it had to make tuning a 100 shot on pump gas a little bit easier.

 

vitaras in what block?

 

y7, will that work?

 

Don't mickey mouse the engine management. That would defeat the whole purpose. Convert your car to OBD2 (that would be easier than your current plan) and run the stock 3 stage ECU, or get some real engine management like the AEM EMS.

Running 12 valve mode over 2500 RPM is going to hurt your mileage compared to running the VTEC-E crossover properly.

 

So basically the economy vtec?

 

a 5spd obd2 ecu d15b ecu is IMPOSSIBLE to find, like 90% of those cars come with a CVT automatic trans... I'm almost positive that I can get it to run just like stock with ECtune.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Damon Reeves &raquo;</TD></TR><TR><TD CLASS="quote">So basically the economy vtec?</TD></TR></TABLE>

Economy vtec until 3k rpm and then exactly like a y8 from there on out.

 

one thing come to mind here....... you want to have you cake and eat it too.... good luck

 

im intrested in your build up specifications (parts, suppies,machine work).im working on a delsol, and would like to get 60mpg . any information or web sites would be appreciated. do you know of any makers of lower final gears for a 5spd delsol trans.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by suspendedHatch &raquo;</TD></TR><TR><TD CLASS="quote">Don't mickey mouse the engine management. That would defeat the whole purpose. Convert your car to OBD2 (that would be easier than your current plan) and run the stock 3 stage ECU, or get some real engine management like the AEM EMS.

Running 12 valve mode over 2500 RPM is going to hurt your mileage compared to running the VTEC-E crossover properly.</TD></TR></TABLE>

maybe if you got an obd1 p72 ecu and wire the IAB secondaries into the 2nd vtec solenoid. You'd have to have a good tuner though.

 

How about rods? Think the stock y7's will be ok?