Keef's Car Thread | Wheels on the Bus | 09/08/23

[nobuffalo]

Gotcha. Right near where I work there's one setting at a shop. Stopped in and had a few words with the guy. Big gash in the passenger quarter panel, but aside from that and the fender it wasn't in too bad of shape. He said he's looking to get around 2500. I later found it here on craigslist. Damn, too bad about the body damage, even if it is the lesser S4 it would still be a cool car to have.

 

[Keef]

Somebody told me E28s are reliable cars...so why is my friend's broken? Somebody told me that it takes 15 years for cars to break down all the time...so why is my friend's MK4 Golf broken (in various ways)? Apparently Nissan makes pretty reliable cars, so why are all my friends with 240s rebuilding them from the ground up for the new "season"? Season of what, season of running? A good friend has done all sorts of work to his Integra sedan and the thing makes some pretty good power...when it's running. Another friend of mine has various cars including an AE86 and an MK3 Supra, neither of which operate well enough to be called "cars". My cousin's 1981 E21 with it's swapped-on carbueretor works great, albeit slowly, and only when the rigged throttle cable isn't fraying in half.

The only car in the troop that works consistently is my Black Magic Mobile. And a few miles away, Speed Junkie's Miata has been going strong at redline with a clogged lifter and pulling 3gs with a stock oil pan for like 500k miles.

Mazda 4 lyfe.

 

[Eric.]

Did you just call rotaries reliable?



My 87 MR2 is pretty much all there. Needs a trans to have 5th gear again, but runs and drives like a champ otherwise.

 

[Rotary Junkie]

Did you just call rotaries reliable?

Suck-air ones, yes.

My 87 MR2 is pretty much all there. Needs a trans to have 5th gear again, but runs and drives like a champ otherwise.

Beat on it and have it hold up like Speed Junkie's Miata has and then we'll talk.

 

[Tornado]

Somebody told me E28s are reliable cars...so why is my friend's broken? Somebody told me that it takes 15 years for cars to break down all the time...so why is my friend's MK4 Golf broken (in various ways)? Apparently Nissan makes pretty reliable cars, so why are all my friends with 240s rebuilding them from the ground up for the new "season"? Season of what, season of running? A good friend has done all sorts of work to his Integra sedan and the thing makes some pretty good power...when it's running. Another friend of mine has various cars including an AE86 and an MK3 Supra, neither of which operate well enough to be called "cars". My cousin's 1981 E21 with it's swapped-on carbueretor works great, albeit slowly, and only when the rigged throttle cable isn't fraying in half.

The only car in the troop that works consistently is my Black Magic Mobile. And a few miles away, Speed Junkie's Miata has been going strong at redline with a clogged lifter and pulling 3gs with a stock oil pan for like 500k miles.

Mazda 4 lyfe.

You know, this is the kind of post that is usually followed almost immediately by a catastrophic part failure.

 

[Perfect Balance]

The only car in the troop that works consistently is my Black Magic Mobile. And a few miles away, Speed Junkie's Miata has been going strong at redline with a clogged lifter and pulling 3gs with a stock oil pan for like 500k miles.

Mazda 4 lyfe.

Burns oil son.

LOTS of VERY hard driving have started to leave their mark.


BTW my 240sx started after sitting in a field for 3 years.

Oh, and 230,000 miles. Lets see your RX-7 do that.

 

[Keef]

You know, this is the kind of post that is usually followed almost immediately by a catastrophic part failure.

Touche.

Lately my brake pedal feels like I'm stepping in quick sand. But...that has nothing to do with the engine. Take my buddy's E28 for example: Thursday night I drove it to the restaurant, and he drove it back, working perfectly. Today I got word that it is "broken" and in the shop. He couldn't give me any more details beyond "broken".

Like Rotary Junkie said, suck-air rotaries go for a good while as long as you change the oil every Sunday afternoon. And you don't even have to change the timing belt!

 

[Keef]

 

[Keef]

It actually beat my expectations by a whole 10 horsepower. I was expecting the first run to be a waste due to carbon buildup after idling for so long, or that it would be tricky to get clean runs because of the cooling fan kicking on and sapping power, but these were non-issues, obviously. The thing was surprisingly consistent - beyond that, the fact that it continued to gain power even though these runs were in quick succession and the cooling fan was a tiny little thing.

Factory crank power was 160 @ 7500 and torque was 140 @ 4500. On the power side, this chart shows a loss of only 13.x percent, which is probably unrealistic. Compensating for a 15% loss, the engine is making 164 horses. At a 20% loss, which is probably a realistic number considering the car's age, it's making 175 horses. Honestly, that sounds about right. According to Racing Beat, their test pipe/presilencer pipe on an S4 FC (146hp) gains an impressive 18 horses. My exhaust, a poorly bent and small diameter straight pipe with fart can, apparently gained 15 horses on the already-more-powerful S5 engine. I'd call that progress, especially since this crappy pipe only cost me $80! Still though, I plan to upgrade to Racing Beat and Buddy Club exhaust pieces (for quite a bit of money), mostly to have legit not-crappy parts, and also to see if they actually give any improvement.

EDIT: Triple post ftw.

 

[Perfect Balance]

Not bad at all, honestly. I'd like to know how much power my car makes, although I have a feeling it would pull it's "I'm not gonna run right" moods right as I was doing it, and I'd end up with 110whp.

 

[Keef]

"I'm not gonna run right" moods

My car's engine has politely refused any opportunities I've given it to screw up on me, starting with buying it in the first place up to this most recent dyno session.

Color me impressed.

Also, the torque plateau and jump in power at ~5400 rpm can be attributed to my auxiliary intake ports and injectors engaging. That's also the rpm at which fuel efficiency goes from pretty bad to incredibly bad. I'd like to find a bolt-on way to keep the power on boil up to the 8000 rpm redline, but I have a feeling that's just the limits of the stock ports. The thing already flows a tremendous amount of air for its tiny displacement and the only way to get more is to port it or turbo it.

*considers T2 swap*

 

[Perfect Balance]

*considers T2 swap*

Makes for a fun car, and surprisingly quick given the power numbers.

 

[Keef]

It would be about -200 pounds quicker than my cousin's supercharged Cobalt SS. But that car was...abnormally fast. I know a simple K&N didn't make it that much faster than all the others. Something was wrong with that car, in a good way.



Pah!

That's my last run, the green run on the dyno sheet, to about 8400 rpm and 125 mph.

 

[Rotary Junkie]

Mmmmm, fire.

 

[Eric.]

Maybe some high compression pistons or something would help you make power to 8k?

 

[Rotary Junkie]

Maybe some high compression pistons or something would help you make power to 8k?

Or maybe a bigger cam and upgraded valve springs to stop valve float?

 

[Keef]

Or maybe if I put some of THIS in my gas tank!

 

[Omnis]

Lol, Keef, nice plates. Slotary?

 

[Eric.]

I wanna get dynoed, but its so expensive for the only local place. $100/pull. **** that. Hopeful for around 210whp.

 

[Keef]

I wanna get dynoed, but its so expensive for the only local place. $100/pull. **** that. Hopeful for around 210whp.

Damn, what do you have done? A stock one would only put down about 170.

 

[Joey D]

You're car sucked less then I thought it would. I guess that's a compliment.

 

[Eric.]

Damn, what do you have done? A stock one would only put down about 170.

Skunk2 race header, vibrant catback, and a Hondata base tune. Stock they do 170-180. There was a noticeable gain with the header. And a ridiculous gain with the tune. 210 might be too high. I don't know. It feels right. Once I get a cold air ill get a real tune on it.

Oh and I've gone from consistent 10.3@75 in the 1/8th to around 9.7@78mph with lots of wheelspin. Should be able to do 9.5 or lower if I change my launch control and having star specs on should get it even lower.

 

[Keef]

launch control

Launch control!?

This is what I think of your launch control:

What you gonna do about it?

 

[Keef]

I'm telling you, there's something up with the edit and post buttons lately.

 

[Eric.]

Yeah its really just a two-step rev limiter. Set to 3200rpm right now, since I've been too lazy to go reflash the car with it set to a higher rpm...VTEC at 4250rpm is awesome though!

 

[Thatman]

GAH! This makes me want to get a turbo version even more! My darn Aux ports....if only they worked...

 

[Keef]

Yeah its really just a two-step rev limiter. Set to 3200rpm right now, since I've been too lazy to go reflash the car with it set to a higher rpm...VTEC at 4250rpm is awesome though!

Two-step, that's what I thought. Ya know, if you slap a Spec 2 on the back of that two-step you'd be a potential winner at Import Alliance's exhaust competition lol. K20 + two-step + straight pipe = retarded.

Have you had the car dynoed with VTEC that low? It probably does gain a good bit of power. VTEC is so high on stock computers so during normal driving you're not going in and out, wasting gas. You should keep an eye on that torque curve though - it's designed to improve torque at high rpm, but may actually decrease it down low. At least that's how it works on old, not-fancy B-series engines. My friend's GSR produces only marginal torque gains with VTEC at 4500 rpm.

GAH! This makes me want to get a turbo version even more! My darn Aux ports....if only they worked...

What's wrong with them?

At least you can remove the air pump on your S4 without messing them up. I can't take mine off because it operates the aux ports, unless I want to use electronic actuation which is complicated.

 

[Eric.]

Its a base Hondata tune, Keef. Meant for an Si with a CAI, Skunk2 header, and catback. I have two of the three, so its relatively close. There's no base tunes that are a closer match, and my AFRs look good. The VTEC crossover is right where it should be. Its almost a linear growth in power now.

 

[eSZee]

Its a base Hondata tune, Keef. Meant for an Si with a CAI, Skunk2 header, and catback. I have two of the three, so its relatively close. There's no base tunes that are a closer match, and my AFRs look good. The VTEC crossover is right where it should be. Its almost a linear growth in power now.

As long as the header is one of the two, then yes.
While not exactly the same as your setup, my older car has a variable intake manifold swapped from a newer car. 2ndary compartment in the manifold opens up to increase the air volume at 5100rpm and gives a huge whp gain til redline. Problem is that setting it too low causes huge TQ losses. Reading up on the newer SI, it seems you shouldn't worry much in terms of power loss when changing the switchover and engagement.
I do have to ask why the TQ graph of an SI is so rough?

 

[Keef]

I do have to ask why the TQ graph of an SI is so rough?

- Import Tuner's 2008 baseline.

VTEC is designed to increase torque at higher rpm, and as you can see, it accomplishes that. That keeps the power flowing for a few more thousand rpm.

As an aside, my 1.3 liter rotary musters 100 torques as low as 2000 rpm. The K20 just hits that mark at 2800 rpm. But whereas mine falls below 100 again at 7200, the K20's stays over 110 for the rest of the rev range.