casio

88IntegraLS (heh, kinda funny how youre dissing the hondas and their vteC engines), do you have any dyno graphs? i remember back when i had my gsr i had a site bookmarked with a 200 wheel hp gsr that ran 13s in street trim. i have since bought a new computer and cant find any good ~200hp dyno sheets for honda engines. i do know of one, but its a D16 which put down 181, but the dyno doesnt show the rpms (though i'm sure dr watson could deduce the info). there's still other variables, though. even dyno sheets are just info on paper. i still prefer the "take it to the pavement" approach as it takes all numbers, chews em up and spits out reality.

drago86

I disagree, the engine only needs to make power through the upper 3000 rpm MAX of the rev band, if you launch right, you will stay in the last 3k of the power band, the shifts wont drop you down below this either. So what really counts is the area under the curve of the last 3k of the revband (assuming peak power occurs here, like in an NA rotary) Any power below point this will do nothing but make the car feel fast on the street, when racing you'll never see below that RPM. If we had a closer ratio box, this could be an even narrower rpm range that actually counts.

I agree that there are way to many slow NA's, but I think this is because anyone who cares alot about 1/4th mile times etc, will just go turbo because it has higher potential, is potentially cheaper, and has a large knowledge base of how to make it work, and work well. I also dont think i'ts lack of money that results in slow NA's, as many on the forum have put many thousands into there cars, rather it is lack of ingenuity. Everyone trys the same things; true duels, SAFC, and a cone filter. Plus theres just not enough people seriously trying to make fast NA's, just a handful as opposted to many thousands trying to make very fast turbos. and of that handful, most will get fed up and go turbo.

koukifc3s

iTrader: (3)

so what would u suggest sir apart from intake exhasut safc?

White_FC

Depends how streetable and what you mean by streetable.

Personally i´ve driven in many a N/A bridgeport rotor on the street and I can´t see what all the fuss is about being terrible on the street.

But thats my opinion.

What I would suggest would then be to do a full brideport on it using TII irons and S5 internals coupled with a good IDA style throttle body/carb setup.

88IntegraLS

Lol.

The close ratio is a fine idea but might necessitate an extra shift which costs a little bit of time, but point taken about the final 3k rpm being where it counts. My 88 Integra had a close ratio tranny and it just masked that car's poor midrange torque. I've ran a couple hondas here and there after I got my FC, and the results were usually the same thing: The hondas had a nice top end but they fall down when they shifted into second. Well ported rotaries still have their original flat torque curve unlike a peaky four cylinder and will pull all across those final 3k rpm at a similar g force, while a peaky motor will fall back and then peak right at the shift point.

Regarding trying the same things: add "huge monster street port" to that list. As some have found out the hard way, doing a big port without a big runner and proper (custom) intake manifold runners while on the stock ecu just produces a dog.

80's Boy

Care to try that against my S2000? 2.2 liters, 8.2k revs, and 211RWHP. Oh and the torque curve is uber flat too...Making generalizations about Honda engines is just foolish.

And for another comparison, when I had a 2000 Civic Si, with the lowly 1.6 B-16, I was able to pull away from RarestRx's GTUs. This was from a 2nd gear roll on too.

drago86

Yes, we need to start seeing some of the IDA injection manifolds and such comming over here, the stock manifolds kinda suck and carbs have to many trade-offs for street applications.

Maxthe7man

FD n/a P-port on the dyno

http://a-ds.serveftp.net/a-rf/video/021.wmv

Same FD on the street...
Sounds pretty streetable to me, jericho transmission and all...

On the street..
http://a-ds.serveftp.net/a-rf/video/029.wmv

From seeing a good handful of pretty powerful n/a's first hand, the most important thing is cranking pressure, I reallly don't think enough tolerances are measured on this side of the pond when rebuilds are done, agreed that monster power is not gonna happen on stock manifolds and ecu programming, their design is biased towards new car driveability and large market acceptance, rather than all out over all hp, the manifold is to long with to small of runners to really take advantage of long duration ports and high rpms. There aren't alot of people really serious about real hi-po n/a power on the streets to take it to the level that some of the turbo guys do in terms of build level, with stand alone ecu, custom manifolds etc etc, I know I am gonna get flamed for this, but most n/a fc owners are to cheap or not really serious enough about their cars(its just a sporty daily driver) to push alot of knoweldge around of efi'd streetable heavily ported n/a engines , alot of the predisposed idea's about p-ports and B-ports, are old ideas, born before the days of being able to tune the motor to the degree we can tune them now, alot of the problems streetability wise and driveability wise were born out of the archaic ancilleries used with the ports, not the ports or the overlap inherent to them, the holley's got bad mileage, the webers and the dellortos left alot to be desired for starting, and day to day operation, and any kind of emission standard, its the same shift in the piston world, fuel delivery methods have really changed the streetability of the previously unstreetable...Good stuff with efi and n/a is happening in Japan, it's probably filter through to here in a year or so..max

88IntegraLS

If your Honda is barely walking a 15 second car, congrats.

KiyoKix

Maxthe7Man has put a really good point, I think most people are really stuck with the old ideas that are "gospel" to most. I don't really believe most of that stuff, it's just what a few people did and couldn't really get to work right (no offense to anyone). As for the N/A guys being cheap, I think that's one of the most true statements I've ever heard. Everyone is looking for cheap power and no work really (well...not everyone 88IntegraLS for one is not ). This is something that just can't happen if you want a "powerful" N/A car that's streetable. Most people don't really put in the time, effort, and money to make the N/A a truly fast car. Hopefully this will change...but I guess we'll just have to see.

Kiyo

RETed

Overlap is the reason this type of porting does not make "low end power".
This is not some "old school" way of thinking; it's physics.
No "modern EFI" computer is going to change that.
Sure, you can get better control, but you cannot overcome the disadvantages the high increase in overlap these porting types produces.

Sure, if you never go under 4,000RPM in your daily driving, I can see it can be possible to "street" even a small peripheral port.
But...how many of us drive like this?
Even I admit, I drive my FC almost 99% of the time under 4kRPM at 99% of the time I'm driving it on the street.
I think most owners in here are like that too - bad assumption?

I've run a plot from my measely dyno run of 250hp versus that 750hp BP monster from KSP Engineering (now over 900PS!).  I'd beat that thing up to 4kRPM.

I think it's a bit irresponsible to be claiming you can drive a PP rotary on the street as a daily driver?


-Ted

(Edit...Thread clean up)

Aaron Cake

iTrader: (1)

Thread closed while I clean up the BS between Maxthe7man and RETed.

Aaron Cake

iTrader: (1)

Thread cleaned and re-opened. It will remain clean, or those involved will be dealt with appropriately.

rx7_ragtop

Prepare to flip...

1988 Convertible (with BBS Convertible wheels)
3" single exhaust with a cat.
Cone type filter

16.1's consistantly, in a 3000+ # car. 130 RWHP.

That's a realistic starting point... before you start porting, etc.

6 port motors don't respond as well to porting- the ports are already big, they're just restricted by the sleeves in there. Pineapple Racing makes replacements that smooth out the airflow.

In porting, just remember that bigger is not always better. Smooth airflow and fairly high port velocity are important.

Maxthe7man

You have nothing to add and feel put out or what?
There are two ways to get power of an n/a, make it bigger, or spin it faster, and to do so involves more port timing...There is no free lunch, more port timing will shift the powerband, but the engine is going to go nowhere fast on stock ports now is it...
I have lived with multi carbbed tunnel ram big blocks on the street, and other cantankerous combinations, most of the problems with reversion and low port velocity , is it weakens the vacuum signal to carbs, and causes low speed fuel ditribution and fuel puddling problems in the intake tracks of inductions systems that are capable of breathing such large amounts of air. EFI being largely a dry flow intake system, eliminates such problems with larger throat intakes and throttle bodies, coupled to that the flexibilty we now have with timing control, in order to get steady maximum state timing with a distributor at high rpms, pretty much the only way to do that was to lock the timing at full advance, and use a retard box for starting, which left the engine flat in the midrange with far to much advance, or overly timed for low speed high load operation(ping) there was no way before to really time the motor, to be driveable under all conditions, with systems like the haltech etcetc, now there is...Much of the , you can't drive that thing on the street stuff comes from books like rx-7 performance handbook , or people that have never tried it and stuff where they were stuck with chokeless carbs, or oversized holleys to extract maximum power, with enough idle jet to fuel a 747, most of that stuff these days belongs in the dumpster, the books and the carbs, its 2004, not 1985.....
The current trend in Japan, is moving away from turbo engines, alot more people are exploring the na path and taming large and long ports with the tunability of efi, now Ted thinks its irresponsible to suggest such things, but you are not gonna make any more power with the stock ports, nor the stock port timing. A rotary is an engine , a really no different than other engines, in order to make more power, we have to spin it faster and increase its volumetric efficiency or make it bigger, we can't make more hp out of a v-8 with stock heads and cams, at a point that stuff has to go, and yes we shift the powerband , but we have to live with it and work with it to get more performance out of the car, if having to rev the car 500 rpm to let out the clucth annoys, change the to a lower rear end gear set, bump the compression, or change your first gear ratio, the "kills bottom end torque thing" is a total load, you adjust to the powerband of your car, and you learn to drive it, and set it up right, even on my latest bridgeport, with the bac valve setup optimally, you could not stall the car in the first gear, from a 1200 rpm idle, you could feather the clutch out and the car would start off in first with out any extra throttle input, you can't even do that in a stock n/a...I don't think anyone is going to build a p-port motor then put a class 4 hitch on and go touring the mountains with a winnebago in tow..
How about a disclaimer, if you are gonna use your rx-7 as a tow truck, don't port your engine.... ...
Max


(Edit...Clean up thread again)

Mills

iTrader: (1)

Ha! I saw that last one b4 it got cleaned...

That's a pretty nice essay, maybe by the time I can afford to turbo my vert there will be a similarly cost effective way to go all motor-without sacrificing everything the vert embodies

Hell, if I could get my vert to feel more like my SE I'd be happy...

88IntegraLS

Very true, and I did some involved research before I ported my 6p 13B, short of twisting jimmi325i's arm to tell me how he did his ports.

I basically went small primary with late closing, medium secondary with barely earlier opening and later closing, and a huge aux port with very late closing and moderately earlier opening. The car, with just weight reduction, intake porting, the street port, and tuning the stock ecu insofar as can be done by angling the airflow meter and bumping up the CAS timing, ran a 15.5 @ 96 consistently the other day on my Gtech. _On stock exhaust_. I just got through getting my RB header on and it freed up another .04 g of acceleration in each gear across the band.

The six port engines give an unusual opportunity for the designer of a custom intake manifold to tune three different runner lengths for each rpm band where their respective ports are most well suited. If I weren't about to follow my pipe dreams of putting together my own supercharging conversion using an M62 Mercedes trim Eaton roots, I would be fabbing up such an RX-8 style intake manifold.

But let's face it. Forced induction with good tuning, good intercooling, and properly matched compressor flow to engine flow is where it's at for real bang to buck power return on investment.

Zbrown did a great thing for inspiring many of us to supercharge our NA's. Now it is up to the rest of us to optimize the installation and start breaking 13's with our former FC NAs. Let's just hope I don't break my driveline in the process.

88IntegraLS

Lol

Correct porting on a six port NA will yield slightly more off-idle torque, significantly more midrange torque, and of course, substantially more top end power. I have found that adding a header to the stock cat / cat back has a similar but more slight effect.

Point taken about wild ports on race cars, however.

wpgrexx

What did Jimmi325i do to the ports that is so special. Even after I bought the motor off him he didn't reveal all his secrets.But it is a helluva torquey motor.

88IntegraLS

PLEASE TAKE IT APART if it ever blows on you and show me the ports. Whatever he did, I'd like to know. You and I both know that power down low as well as up high is a sweet sweet combination, and that thing put down 167 rwhp at like 5k rpm with 140+ torque. He had trouble with the dyno so it couldn't make a full pull to 8k, but I'd guess that thing would approach the 200 mark. The special thing about that engine is the abnormally large amount of torque it makes all over the power band. Torque x rpm = power. If a motor keeps making the same amount of torque all the way up the revs, its power will just keep climbing as high as you can spin it.

But yeah, I'd really like to see how he ported that thing if it ever needs a rebuild and you take it apart.

wpgrexx

I have a dyno sheet he gave me that showed it having 161 hp and 159 torque but the funny thing is the corresponding A/F ratio for the same pull has it running very rich. Lots of room for improvement. the torque and hp are almost identical lines.

wpgrexx

oh and BTW I dont plan on having to take it apart for a while.......

drago86

mmm,.. endoscoping pics of the ports?

flamin-roids

I was told of a first gen with a periphiral (spelling?) port and dual carbs and some other **** pushing 290rwhp and a 10.90 1/4 mile. My friends '87 TII pushed 177rwhp with a racing flywheel and intake with no exhaust. Thats right just a downpipe and he only pushed 177 rwhp.

slvr7

iTrader: (1)

Grassroots Motorsports magazine had a 13B built by Tri-Point for their rotary spitfire project car. That motor, with a 1/2 bridge port (aux only), standalone (Tec-III) and twin throttle bodies on a weber - type manifold made 193 rwhp.
In a 1600 lb car it runs mid 12's
It's got me thinking bigtime about a little MGB for sale up the street from me.


Curtis
'86 GXL autox'r
currently undergoing streetport rebuild