Extreme Speed vs. Intake Temps Datalog/Pics. - Honda Prelude Forum

Methods · 10-17-2004, 12:43 PM

Extreme Speed vs. Intake Temps Datalog/Pics.

There was some discussion in another thread about the Intake Temperature characteristics of a 12psi ENDYN modded JRSC. I decided to take a quick snapshot of the data.

Notice in the above picture the beautiful A/F ratio and super low injector duty cyclesâ€¦ (Btw: I tune for 12.5:1 so I am not lean) Fuel pressure is at 30psi (not 90psi). Who would have thought you can run 12psi on 10:1 compression with full ignition timing, street gas, and 200 degree intake temps.

Note that after an insane asylum pull I am just breaking into 200 degrees. That is more than reasonable if you ask me.

I suppose *Someone* is going to point out that it only shows 10.7lbs of boostâ€¦ Boost is just relative to the amount of air that is â€œnotâ€? flowing through the motor. If I were to put my stock cat on, you would see about 13psi on this datalog.

Here is a more revealing datalog that shows you how fast the temperature ramps up and how long it takes to decay. Like advertised, the engine will â€œcruseâ€? around town between 140 and 160. I can easily jam around at 80mph and see 160â€™s. When I stomp the gas and rip it up to a hundred I see a hair above 190. (donâ€™t let the graph fool you, Delta Y is 25).

On the big pull it only took a minute and a half for the temps to drop from over 200F back down to a sane 165F. This was about how long it took me to decelerate and pull off the freeway.

Ahhhhhhhhâ€¦.. You donâ€™t see any RPM vs A/F graphs like this from Jackson Racing. Flat as a pancake all the way through 5th gear. If you try this with a stock JRSC you will most likely cause permanent damage to your ring landsâ€¦. So donâ€™t try anything funny. JRâ€™s funky little fuel pressure trick is good for short bursts, but just wait and see what happens when your fuel pump tries to keep up with 100psi for more than a few secondsâ€¦..

Anyway, there is some data to back up the talk. I want to get a datalog of the engine heat soaking but there just isnâ€™t anywhere around here that I can do that (safely). It is hard to find a place that will allow acceleration from 30 â€“ 100 over and over again without time for things to cool down. One quick 5 second burst to 150 is one thing, doing it over and over again is another.

P.S.

For those of you who are â€œreally sickâ€? yes, the car will break well out of 150mph, it is just a matter of how high you are willing to rev the motor. My rev limiter is at 9000. The motor will blow up before it sees max Speed thoughâ€¦

h22 bb6 · 10-17-2004, 03:52 PM

Nice.

B0b · 10-17-2004, 05:45 PM

that is hoooooooot. as in.. nice..

flip1199 · 10-17-2004, 09:10 PM

so your saying that on that first log your actually boosting 12lbs?? shouldn't the temps raise if it were 12lbs? i'm not really a jrsc kinda guy but what are the normal iat's?

Methods · 10-18-2004, 12:19 AM

ALL of the logs are at â€œ12 psiâ€?. By that I mean I am running both ENDYN pulleys.

The 10.7 that you see is a combination of poor calibration (thanks Hondata) on the 3Bar map sensor and the effects of a high flowing exhaust. I can reach boost levels of 14 psi at some RPM/Load combinations and as little as 10psi at others.

As far as your question about â€œshouldnâ€™t the temps be higher if the boost is at 12psiâ€?â€¦.. Well that is the point of the thread. I have had modification to my blower (and entire motor for that matter) by ENDYN. The affects of these modifications allow me to run 3psi more boost (12psi) at the same temperatures normally seen at 9psi.

During that run my Autometer boost gauge was reading around 12psi.

In my experience, normal IATâ€™s are:

160 for 6psi
190 for 9psi
220 for 12psi

Please refresh my memory if I am wrong, it has been a long time since I ran the stock pulleys.

P.S. PSI is just an illusionâ€¦.. For example, if I stick a banana up my tail pipe and my boost jumps up the 20 psi (due to back pressure) would that mean that I am running more boost? Or, on the other hand (this hand) if I have an extremely high flowing head, header, 3â€? exhaust, no cat, etc. and my boost drops to 11psi (or 10.7 with the 3 bar map sensor error), does that mean I have less boost? Nope, just means I have less backpressure and more flow.

Artifex · 10-18-2004, 09:03 AM

Quote:

Originally Posted by Methods

In my experience, normal IATâ€™s are:

160 for 6psi
190 for 9psi
220 for 12psi

I just have a quick question for you. Are you sure the Hondata IAT display isn't "saturating" at 200 degrees? When I look at the tach screen you show, it looks like the top of the scale is set at 200. What happens when actual IATs are higher? Does it cut off at the limits of the display, or will it show higher?

Methods · 10-18-2004, 11:32 AM

I am absolutely positive. That run actually peaks out at 204 F.

If you look closely at the data the temp levels off because I let off the gas.

I will post another screen shot that shows a temperature greater than 200Fâ€¦. I KNEW someone was going to point that outâ€¦â€¦

Good eye by the way, that is the type of thinking I like to see.

Artifex · 10-18-2004, 12:03 PM

Quote:

Originally Posted by Methods

I am absolutely positive. That run actually peaks out at 204 F.

If you look closely at the data the temp levels off because I let off the gas.

I will post another screen shot that shows a temperature greater than 200Fâ€¦. I KNEW someone was going to point that outâ€¦â€¦

Good eye by the way, that is the type of thinking I like to see.

Just adding my brainpower.

Methods, I love your setup. It's really hard for me to believe your efficiency levels, but your datalogs don't lie. I am a believer in the Endyn magic, so I'm not here to give you any hard time about that (I have been on TOO's boards for the last 3+ yrs). I just never expected Larry's work to yeild such good results to a relatively old Roots style blower.

BTW, I'm glad you have an account on PO. The discussion here is far and away better than most other BBS boards. I would love to hear your input on the other FI subjects we discuss here.

Methods · 10-18-2004, 12:24 PM

Now I am a little intriguedâ€¦

What sort of temperatures are you guys expecting to see? 300 degrees?

I actually have a 15psi pulley being made by Larry right now for track use only.
(does that get your chicken going?)

I know another guy that ran the 15psi pulley on a B18 (10 second CRX)â€¦. Word is that he saw temps in the 300 range, but I donâ€™t think I will see over 250. He ended up squeezing to drop his temps.

Now I am Irkedâ€¦. I feel like running home to get that datalog. Maybe I will do it at lunch. â€œIâ€? know for myself that I have seen as much as 215 degrees F, but I can see why you guys would be skeptical. I donâ€™t want there to be ANY doubts about this.

That settles it, I am going home early to get that datalog.

Methods · 10-18-2004, 07:30 PM

Yes, Hondata will datalog temperatures over 200F, here is proof.

h22 bb6 · 10-19-2004, 12:25 AM

Sharkcohen has stated previously he's seen IAT's over 200 on hot days in Cali @ 9 psi with just the blower, so that really goes in line with what you would expect to see with the Endyn modded blower.

At what point does detonation become a risk because of high IAT's? I mean I heard an intercooled turbocharged application only see's temps of around 130-140, maybe 160 after a hard session.

Methods · 10-19-2004, 08:26 AM

Normally, I would already be â€œinâ€? that range that causes detonation.

I donâ€™t know what Larry at ENDYN does, but it works. Like I have said before:

10:1 compression
12psi
Full timing
200 intake temps
12.5:1 A/F

No detonation.

Must be magicâ€¦

h22 bb6 · 10-20-2004, 01:05 AM

You also have a lot of Endyn headwork as well and the Endyn blower mod, which is probably close to $3k, if not more.

Methods · 10-20-2004, 08:56 AM

The way that I look at my (ENDYN) investment into my motor is as follows:

The first 10% was for performance
The last 90% was for safety, reliability, and peace of mind.

If I hadnâ€™t had the ENDYN work done I would have sold the blower long ago, probably the Prelude too.

ENDYN work is also an investmentâ€¦.. Larry can only do so many heads and he does very VERY few H22 heads. Larry is very well known in some circles and the head will retain its value for years to come. One thing in life that you canâ€™t just â€œbuyâ€? is artwork. Be it a famous painter, a famous sculptor, or a famous head porter.

If you have ever meet Larry you would know that just â€œknowingâ€? him is a return all its own. Larry is one of those very special people that only come around once in lifeâ€¦.. The man is a Philosopher, Scientist, Comedian, and all around generous person.