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93 Civic HB SI, 95 Civic HB CX
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Were you wanting to make more power?

What kind of dyno was used? Hub or roller type?

Your power level isn't too wild honestly, all things considered with your build specs.

Comparing your build and turbo specs, your turbo moves a less CFM at the same boost pressure than mine does, but not that much less. Also since you're not long rod, you're likely 8:1 or below, mine is around 8.5:1 static comp.

Keeping this in mind, use my build for comparisons sake.

My grey car has 2.5" full exhaust (sidepipe) with resonator, a GT32 journal bearing turbo, crappy cast mani with gate on #1 runner, but it has a good cam and port matched everything in the head.

On 15psi, it made 310 whp with a very reputable D series tuner dialing in timing as it should be for a D series on pump gas.

Since you have a cam, staggered runner top mount manifold for properly timed pulses, central mounted WG with a 3" bumper dumper, you move air out much more efficiently than I do.

If your tuner has timing set more agressive (most tuners not familiar with D series will), i could easily see you making what you're making at 16psi at your estimated CFM at 7000ish rpm.

Its not too unexpected.
 

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First off, thank you for the thoughtful response.

This was on a Mainline Hub dyno and yes I'm looking to put the car on e85 so I can hit 350-400whp on a flex-fuel setup.
Hub dyno's will usually show a bit higher than rollers will, but are very accurate.

You don't get the real life friction loss of rolling tires clamped the hell down with HD ratchet straps on hub dynos. The correction algorithm will get close, but usually dont simulate the full picture, so your whp at the hubs will show to be a bit higher.

Doing a rip on a roller will likely show 310-315, so you're right where you should be!

When the tuner said it wasnt responding to more boost, what does he mean? How much more boost did he try?

I wonder if he likely stopped going higher to avoid det on pump gas, going beyond 300ish whp starts to get into that "sketchy" territory, regardless if you use boost or timing to try and go higher. Definitely use more boost for power, over timing increases on these engines, your head gasket and bottom end bearings will thank you.

13.5 degrees at 16psi 7k is a spicy for a D!

I'm tuned at 15.75 degrees at 8psi 7500rpm!

At 20psi, I'm at 7 degrees 7500rpm, and it pulls like a raped ape.

I wonder how much experience your tuner has with D series engines? These engines want lower timing and higher boost, compared to engines that have larger bore/piston diameters.
 

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maybe the garrett is just that much better of a design than the maxpleeding turbs.?
Possibly, maybe lol.

However, with it making this power at this boost 20psi would make maybe 300whp which really doesn't seem right.
Did you mean 400whp here? Cause you're already over this power level lol.

Honestly because of the lack of timing we can throw at these engines on pump or E85 due to D series architecture limitations, boost is used to make power safely over any increases in timing, which should stay conservative to keep cylinder pressure dwell to a minimum to avoid popping head gaskets.
 

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Im a little confused you say that the hub dyno is close but say that if i did a rip on one i would put down 300-315 which is a 70-80hp difference. The tuner also used to have a roller dyno and I asked what the difference between his current hub dyno was and a dyno jet/mustang dyno and he said it should be somewhere in the middle. Again he said that the car should be making at least more than 235 at 16psi. He's tuned a ton of hondas and even tuned a del sol that made 457whp at 22psi on the old roller dyno. Also, when he was saying responding to boost he meant working up to 16psi which he said was the limit for safety on pump gas. I plan on putting a flex sensor in soon and shooting for 350-400 but, if the car isn't behaving right I want to get that worked out before just shoving boost in it.
Dude, I'm so sorry I must have been smoking crack...

I literally thought your thread title said 335whp at 16psi!

Forget everything I've said so far lmao.

Ok, coming down off my crackpipe, again I apologize, lets re-discuss things.

235whp at 16psi, on your turbo, with your manifold and downpipe size. Yeah, something else is going on. With my stock Y8 cam on Engine V1 (vitaras with long rod, about 8.8:1, no port matching, same crappy exhaust mani), I made 250-260ish whp at about 15psi with my same turbo, so I'd expect you to be around the same at 16psi with your turbo.

And your tuner said adding timing and boost didn't make the engine respond then huh? As @Soul Engineering said, definitely check for boost leaks and other manifold leaks.

  • What is your mechanical cam timing set to? Stock? What about base ignition timing?
  • What do your cold and warm compression readings say?
  • What is valve lash set to cold?
  • Is VTEC engaging, and engine feels like it runs smoothly when it engages?
  • No pushing coolant or similar under boost?
  • Could wastegate be stuck open, or unable to vent the top chamber effectively? What frequency/duty cycle is being used to control the wastegate with the MAC solenoid?
  • Your camshaft, do you know how much baked in overlap it has in VTEC?
    • I tried finding specs for it, it doesn't say the 105300 is a turbo specific camshaft. Do you have cam card for it? Pics?
    • Curious if its an N/A specific grind. If it is, it will have a lot of overlap in VTEC, so in boost, you'll be blowing all your charge air out the tail pipe! Need to verify overlap based on cam card info.
Off the top of my head, these are the things that come to mind to check.

I hope the dyno operator set the dyno up correctly as well lol... just one other thing to be aware of! If they got the setup wrong, then it will be calculating whp incorrectly. But by the way you describe this guy, he's used it a bunch and that shouldn't be an issue...
 

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or the ports are a bit small/off center,
This!

With Engine V1 I just slapped the manifold on there, and went. The stainless gasket I used had ports smaller than both head/manifold holes too lol.

With Engine V2 I took the time to port match, and found that the crappy cast manifold basically constructed a few 1/4" solid walls of restriction. All the runners had a wall that looked like this:

Jaw Bicycle part Gas Jewellery Helmet
 
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