My car had been misfiring and crap on the dyno and generally not behaving. So after replacing the cap, rotor, spark plugs, spark plug wires and ignition coil, it started behaving a little better.

I still had a problem with the boost controller/wastegate. It was pretty strange, the boost would start slipping from 6000->7500, then after like 7800 it fell like a rock. Strange. So, the peak numbers aren't great, but the "area under the curve" is pretty nice. It feels stronger on the street than it shows on the dyno, but if that curve holds true on the track I'll be short-shifting into 5th at 8000 RPM.

(The current working theories on the boost falling are wastegate spring or downpipe bottleneck, or both).

The peak boost is 1.2 bar (~17.5 psi) at about 6000 RPM, and at redline it's like 0.4 bar.

I may come back and try with 14 PSI wastegate, or a manual boost controller. Profec B Spec 2 sucks ***! I'm starting to get a hang of it but it takes way too long to figure out how to get it to hold boost, and then it doesn't act the same in all gears anyway.

Turbo is a GT2871R on the GReddy manifold, with GReddy downpipe. 10 PSI wastegate spring in a Tial 38mm wastegate. Motor is a B18C5, 9:1 compression JE Pisons, Eagle rods, stock sleeves.

The caR is built for HPDE/Time Trials, not drag racing, so don't bother telling me I need a bigger turbo Hopefully it spools quick on the track, I'm a little disappointed that it need to be so high RPM to get to peak torque. Oh well, not too shabby!

Anhow, here's the graph.... you can see the boost/torque fall off... if it wasn't falling off, 350/375 would be pretty easy to get.



(Old dyno thread: with stock motor and GReddy 18G. 295 WHP, 222 Tq.)
https://honda-tech.com/zerothread?id=987108

 

One more note.. It holds more b00st on the street than on the dyno. Stupid dyno. Maybe I should get the 1-bar wastegate spring.

 

I hope she's reliable for ya next weekend!

 

Wow, great numbers Chris! Glad to see she's up and running again. By the way, where are the picutres of your basketball colored wheels? Or did I miss something?

 

isnt that a lot of boost to be running on stock sleeves??? how is traction with that kind of power?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Erik95LS &raquo;</TD></TR><TR><TD CLASS="quote">Wow, great numbers Chris! Glad to see she's up and running again. By the way, where are the picutres of your basketball colored wheels? Or did I miss something? </TD></TR></TABLE>

The orange wheels are sitting at Frisby Race Tire waiting for some 205/50R15 Hankook Z211 (50 compound) to come in.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dbl Ey! &raquo;</TD></TR><TR><TD CLASS="quote">I hope she's reliable for ya next weekend! </TD></TR></TABLE>

Yeah me too. I expect little ****, since the motor's been out of the car and new turbo plumbing has gone in for oil and coolant lines. No worries, I finally managed to bolt a fire extinguisher to the roll bar.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RTW &raquo;</TD></TR><TR><TD CLASS="quote">isnt that a lot of boost to be running on stock sleeves??? how is traction with that kind of power?</TD></TR></TABLE>

Stock sleeves should be OK for 400 WHP.

Traction is good in 3rd gear on up. I sometimes get a little chirp in 3rd when the turbo spools though. Should be better with the R compounds.



Modified by Chris F at 11:46 AM 4/24/2005

 

Dynos looks good, def. lots of area under the curve.
Why did you go with such a low compression, couldnt you have gone with like 9.5 or 10.1 to improve off boost response.

 

when you get rid of the Greddy downpipe your power will jump everywhere. Looks good though. I would definately get a better downpipe made, specially with that turbo, it should come on a bit quicker.

scott

 

I want b00st.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by answerx &raquo;</TD></TR><TR><TD CLASS="quote">Dynos looks good, def. lots of area under the curve.
Why did you go with such a low compression, couldnt you have gone with like 9.5 or 10.1 to improve off boost response. </TD></TR></TABLE>

Considering my power goals are kinda modest, 9.5:1 might have been a better choice. Lower compression is easier to tune, more resistant to changes in temperature and bad gas etc. etc....

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by scooter &raquo;</TD></TR><TR><TD CLASS="quote">when you get rid of the Greddy downpipe your power will jump everywhere. Looks good though. I would definately get a better downpipe made, specially with that turbo, it should come on a bit quicker.</TD></TR></TABLE>

It's a slippery slope, man. First I get a bigger downpipe and start making 400 WHP. Then I start to lean out up top so I need bigger injectors and fuel pump. Then I crack a sleeve and rebuild the whole thing again

I don't REALLY REALLY need 350 WHP.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by opie &raquo;</TD></TR><TR><TD CLASS="quote">I want b00st.</TD></TR></TABLE>



At least you don't have to babysit your motoR between HPDE runs. I'm always wondering what's going to melt next with all that heat under the hood. It gave me a good scare on the dyno, the dipstick popped out of the t00b and oil sprayed everywhere, from the exhaust manifold to the windshield. It was enough smoke that I grabbed a fire extinguisher, just in case.

My car is a ticking oil grenade.

 

for all ITR-T's. hotness. -Shawn

 

Whoa, all on stock interals.

 

Chris the curve looks awesome. how is spool compared to the 18G?. sell the spec 2 and get the profec type s or a spec 1 like I have. it even would hold boost with the internal gate on the 18G.

did that turbo bolt right up? no mods the the flange?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chris F &raquo;</TD></TR><TR><TD CLASS="quote">The caR is built for HPDE/Time Trials, not drag racing, so don't bother telling me I need a bigger turbo
</TD></TR></TABLE>

Why did you change the 18G turbo?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BoostR41 &raquo;</TD></TR><TR><TD CLASS="quote">Chris the curve looks awesome. how is spool compared to the 18G?. sell the spec 2 and get the profec type s or a spec 1 like I have. it even would hold boost with the internal gate on the 18G.

did that turbo bolt right up? no mods the the flange?</TD></TR></TABLE>

Spool is quick above 5000 RPM. It's hard to compare, since most of the time with the 18G I was at stock compression, but the 18G was previously <U>faster</U> with stock compression. After getting lower compression, it actually seems kinda similar between the GT2871R and the 18G. I'll have to get the new setup on a track to compare.

It was a bolt-on mod, except for the addition of coolant lines, and the oil lines are different. The oil line is pretty bizarre, the feed is a banjo bolt off of a harley brake system or something, nothing else would fit underneath the manifold.

I would NOT replace the 18G with another turbo again, unless the bearings were shot like mine were. Hopefully the ball bearings in the GT turbo are better! Maybe the water cooling will help.

-Chris

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Pompiuses &raquo;</TD></TR><TR><TD CLASS="quote">Why did you change the 18G turbo?
</TD></TR></TABLE>

Bearings were shot, that's the only reason. I really liked the 18G.

 

Looks nice Chris.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chris F &raquo;</TD></TR><TR><TD CLASS="quote">

Bearings were shot, that's the only reason. I really liked the 18G.</TD></TR></TABLE>

How many miles did you put on the turbo?

How's the difference in on-boost throttle respons now that you've got lower compression? I'd imagine off-boost throttle respons (below 4000rpm) must be must be pretty shitty?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Pompiuses &raquo;</TD></TR><TR><TD CLASS="quote">How many miles did you put on the turbo?

How's the difference in on-boost throttle respons now that you've got lower compression? I'd imagine off-boost throttle respons (below 4000rpm) must be must be pretty shitty?</TD></TR></TABLE>

Turbo had 10,000 miles and 7 days of HPDE. I'm sure the HPDE killed it.

Throttle response off-boost is worse than it was with the higher compression, but I wouldn't call it shitty. It's totally fine for daily driving and stuff, but I can't be as lazy before and leave it in a higher gear at the track (I could go pretty quickly in 4th gear as long as I stayed above 4000 RPM with the old setup, now I'd want to stay above 5000).

-Chris

 

what flange did you say that turbo you bought has on it?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chris F &raquo;</TD></TR><TR><TD CLASS="quote">(I could go pretty quickly in 4th gear as long as I stayed above 4000 RPM with the old setup, now I'd want to stay above 5000).
</TD></TR></TABLE>

sounds like you need a final drive y0

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Erik95LS &raquo;</TD></TR><TR><TD CLASS="quote">

sounds like you need a final drive y0 </TD></TR></TABLE>

No way, then I won't get up to 150 on the straights!

 

What kind of mileage are ou getting on the highway driving ~65-70 or so?

Not that it really matters, but its nice not to have to fill up all the time (I used to get 22 on a good day).

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zygspeed &raquo;</TD></TR><TR><TD CLASS="quote">What kind of mileage are ou getting on the highway driving ~65-70 or so?

Not that it really matters, but its nice not to have to fill up all the time (I used to get 22 on a good day).</TD></TR></TABLE>

Dunno about the latest MPG, but yeah city 22, highway maybe 25. Not great. I do boost sometimes, and drive kinda quick on the highway (80 MPH average around here).

If I ran it in open loop, I could lean it out on the highway and get way more. But naaah.

-Chris

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Chris F &raquo;</TD></TR><TR><TD CLASS="quote">Throttle response off-boost is worse than it was with the higher compression, but I wouldn't call it shitty.
</TD></TR></TABLE>

So you didn't really notice any change in throttle response on-boost with the lower compression?