342 hp dyno & 11.19 @ 123.80 video
12-02-07, 02:01 AM
#77
Rotary Enthusiast
Join Date: Mar 2001
Location: Edwards, CA
Posts: 1,023
Likes: 0
Received 0 Likes
on
0 Posts
Nice runs, Tom.
Your car is a perfect example of what a well cared for, well driven, bolt on RX-7 should do in good weather.
To the "19 psi will blow your turbos" crowd. You can't just saw they'll pop at a certain pressure. Since pressure is normally measured at the intake manifold, what you see on the gauge is not what you're getting right at the turbos. If you have good piping (intake and charge), a good intercooler with low pressure drop, and no boost leaks, your 19 psi at the manifold could very well be ~20 psi at the turbos. On the other hand, folks with boost leaks, crappy (cough ebay) intercoolers, poorly thought out intakes, etc may be asking for well over 20 psi at the turbos just to get 15 psi on their boost gauge.
Even with that said, some of these turbos have come apart with much less demanded of them -yours must be a wednesday set
As far as the dyno, I'm sure if you looked at your uncorrected numbers with atmopheric conditions similar to those when you went to the track, you'd probably be making 380 or so. Also have to factor in the effect of a cool 100+mph airmass hitting your intercooler -difficult to capture that on the dyno.
Your car is a perfect example of what a well cared for, well driven, bolt on RX-7 should do in good weather.
To the "19 psi will blow your turbos" crowd. You can't just saw they'll pop at a certain pressure. Since pressure is normally measured at the intake manifold, what you see on the gauge is not what you're getting right at the turbos. If you have good piping (intake and charge), a good intercooler with low pressure drop, and no boost leaks, your 19 psi at the manifold could very well be ~20 psi at the turbos. On the other hand, folks with boost leaks, crappy (cough ebay) intercoolers, poorly thought out intakes, etc may be asking for well over 20 psi at the turbos just to get 15 psi on their boost gauge.
Even with that said, some of these turbos have come apart with much less demanded of them -yours must be a wednesday set
As far as the dyno, I'm sure if you looked at your uncorrected numbers with atmopheric conditions similar to those when you went to the track, you'd probably be making 380 or so. Also have to factor in the effect of a cool 100+mph airmass hitting your intercooler -difficult to capture that on the dyno.
Last edited by Marshall; 12-02-07 at 02:15 AM.
12-02-07, 06:13 PM
#78
Eats, Sleeps, Dreams Rotary
. Since pressure is normally measured at the intake manifold, what you see on the gauge is not what you're getting right at the turbos. If you have good piping (intake and charge), a good intercooler with low pressure drop, and no boost leaks, your 19 psi at the manifold could very well be ~20 psi at the turbos. On the other hand, folks with boost leaks, crappy (cough ebay) intercoolers, poorly thought out intakes, etc may be asking for well over 20 psi at the turbos just to get 15 psi on their boost gauge.
.
.
12-09-07, 11:16 AM
#82
"I do believe the driving can contribute to higher than normal trap speeds, it doesn't just depend on the amount of hp. If you shift gears slower or get a slower launch, that doesn't help get you a high trap speed. The faster you do everything the whole way down the track, the faster your trap speed will be at the end!"
You calling me a granny shiffter!!!
You calling me a granny shiffter!!!
12-27-07, 03:51 PM
#85
Question: what was your target AFRs for boost pressures above 12 psi? Looks like you were getting 10:1 on the dyno... were those runs @ 19 psi? What gas are you using? Also, what kind of timing are you running during full boost to redline... would you care to share your PFC map
Another question: where did you plumb the pressure source for your boost controller? If it's after the IC, have you noticed any difference in boost control (spiking, oscillation, etc.) as compared to when it was before it?
Thanks in advance. Nice car and awesome driving!
Another question: where did you plumb the pressure source for your boost controller? If it's after the IC, have you noticed any difference in boost control (spiking, oscillation, etc.) as compared to when it was before it?
Thanks in advance. Nice car and awesome driving!
12-27-07, 06:21 PM
#86
Wrong. I just recently installed the water/methanol injection kit, and it just made the car slower, I tried all 3 jets and the smallest jet worked best but still made the car slower. I did one dyno pull with the water/meth. injection hooked up and it made 339 hp. One or two of the first two runs on the video at the track was with water/meth, the last run on the video was my best and that was without water/meth. injection, I can feel the car is faster without it.
that's because you have to re-tune when you add auxillary injection to keep the AFR's where there supposed to be. otherwise, you're just adding fuel to the mixture and making it much more rich than it was.
i'm not sure how you've gotten away with running 19psi for this long without breaking an apex seal, but i am sure you're aware it's very risky. it is unsafe to run more than 16psi on 93 octane gas, no matter how pigrich (it looks like your dyno AFR's were sub-10.0:1) your AFR's are and how weak your timing is. there's a pressure/temperature at which the gasoline starts igniting itself. you're skating in that area running 19psi on the stock twins. i guess you've made it this long because of your quality FMIC kit and your (probably) weak timing and very rich AFR's.
your engine would be much safer and probably make the same power at 15-16psi with the AFR's in the low 11's where they should be. at that point is where you could think about raising the boost and adding in some methanol injection (while leaning the fuel out to compensate for the extra meth fuel)
i also noticed while watching your video that you had quite a bit of oil smoke on the dyno when you let off at the top of your run... what does that tell you?
and to the guy that said he ran 21psi on the interstate: i'm surprised it didnt blow up in the few pulls you did. i bet your EGT's were through the roof. you should get on wikipedia figure out how detonation works and why it occurs.
Last edited by jacobcartmill; 12-27-07 at 06:42 PM.
12-29-07, 06:15 PM
#87
Question: what was your target AFRs for boost pressures above 12 psi? Looks like you were getting 10:1 on the dyno... were those runs @ 19 psi? What gas are you using? Also, what kind of timing are you running during full boost to redline... would you care to share your PFC map
Another question: where did you plumb the pressure source for your boost controller? If it's after the IC, have you noticed any difference in boost control (spiking, oscillation, etc.) as compared to when it was before it?
Thanks in advance. Nice car and awesome driving!
Another question: where did you plumb the pressure source for your boost controller? If it's after the IC, have you noticed any difference in boost control (spiking, oscillation, etc.) as compared to when it was before it?
Thanks in advance. Nice car and awesome driving!
I just checked and the pressure source for the greddy profec b-spec 2 boost controller module thing in the engine bay is at the primary turbo (2 vacuum lines), right before where the y-pipe bolts to it. Now that I think about it, that may not be the best place for the pressure source to come from, where is the best source? But then there is the vacuum hose that runs up to the electronic controller (with the **** and buttons) inside the car, that hose comes from where the UIM bolts to the LIM. I don't have any boost control issues. Thanks.
12-29-07, 06:32 PM
#88
that's because you have to re-tune when you add auxillary injection to keep the AFR's where there supposed to be. otherwise, you're just adding fuel to the mixture and making it much more rich than it was.
i'm not sure how you've gotten away with running 19psi for this long without breaking an apex seal, but i am sure you're aware it's very risky. it is unsafe to run more than 16psi on 93 octane gas, no matter how pigrich (it looks like your dyno AFR's were sub-10.0:1) your AFR's are and how weak your timing is. there's a pressure/temperature at which the gasoline starts igniting itself. you're skating in that area running 19psi on the stock twins. i guess you've made it this long because of your quality FMIC kit and your (probably) weak timing and very rich AFR's.
your engine would be much safer and probably make the same power at 15-16psi with the AFR's in the low 11's where they should be. at that point is where you could think about raising the boost and adding in some methanol injection (while leaning the fuel out to compensate for the extra meth fuel)
i also noticed while watching your video that you had quite a bit of oil smoke on the dyno when you let off at the top of your run... what does that tell you?
and to the guy that said he ran 21psi on the interstate: i'm surprised it didnt blow up in the few pulls you did. i bet your EGT's were through the roof. you should get on wikipedia figure out how detonation works and why it occurs.
i'm not sure how you've gotten away with running 19psi for this long without breaking an apex seal, but i am sure you're aware it's very risky. it is unsafe to run more than 16psi on 93 octane gas, no matter how pigrich (it looks like your dyno AFR's were sub-10.0:1) your AFR's are and how weak your timing is. there's a pressure/temperature at which the gasoline starts igniting itself. you're skating in that area running 19psi on the stock twins. i guess you've made it this long because of your quality FMIC kit and your (probably) weak timing and very rich AFR's.
your engine would be much safer and probably make the same power at 15-16psi with the AFR's in the low 11's where they should be. at that point is where you could think about raising the boost and adding in some methanol injection (while leaning the fuel out to compensate for the extra meth fuel)
i also noticed while watching your video that you had quite a bit of oil smoke on the dyno when you let off at the top of your run... what does that tell you?
and to the guy that said he ran 21psi on the interstate: i'm surprised it didnt blow up in the few pulls you did. i bet your EGT's were through the roof. you should get on wikipedia figure out how detonation works and why it occurs.
I don't really know, what does that smoke mean? The guys at the dyno place said that was normal, I was worried until they said that and haven't thought about it since.
That is me that ran 21 psi, I've been seeing 20 psi lately in the cold. I've never used an egt gauge on my car, only really tune and monitor the AFR and boost levels, no problems.
12-29-07, 07:45 PM
#89
boost controller pressure source
11 - 11.5 AFRs. That wideband at the dyno was definately way wrong! I logged the pulls on my laptop with my PLX R-500 wideband and the AFRs were like normal 11-11.4 , not way rich like the dyno said, many of the other cars there where showing the same rich readings, and I hope they don't tune cars based off their readings because if they do then they will tune the cars too lean! Maybe that's why you hear stories about people blowing up their RX7s on the dyno cause the widebands they use are not accurate. I think mine has to be accurate, more accurate than theirs readings, or else I don't think it would be so fast running so rich like the dyno said. Yes 19 psi. 93 pump gas. Never changed the timing in the PFC.
I just checked and the pressure source for the greddy profec b-spec 2 boost controller module thing in the engine bay is at the primary turbo (2 vacuum lines), right before where the y-pipe bolts to it. Now that I think about it, that may not be the best place for the pressure source to come from, where is the best source? But then there is the vacuum hose that runs up to the electronic controller (with the **** and buttons) inside the car, that hose comes from where the UIM bolts to the LIM. I don't have any boost control issues. Thanks.
I just checked and the pressure source for the greddy profec b-spec 2 boost controller module thing in the engine bay is at the primary turbo (2 vacuum lines), right before where the y-pipe bolts to it. Now that I think about it, that may not be the best place for the pressure source to come from, where is the best source? But then there is the vacuum hose that runs up to the electronic controller (with the **** and buttons) inside the car, that hose comes from where the UIM bolts to the LIM. I don't have any boost control issues. Thanks.
The reason I asked in the first place is that I read in Chuck Westbrook's (cewrx7r1 on the forums here) notes to plumb AFTER the IC in order to reduce spiking. I was just looking for some verification of that statement, that's all. I imagine that the charge coming out of the IC (of course this will be a little different from one IC to another) is a little less turbulent than the charge coming directly from the turbos, and I also imagine that ANY controller will have an easier time with less uncertainty in the medium to be controlled (boost pressure). Or something like that
Two of my next mods are going to be relocating the IAT as you did, and also relocating the pressure source for my boost controller after the IC. So you don't get spikes between gear changes? I sure do! Haven't figured out how to iron that out...
Your AFRs are pretty lean, eh? Maybe that's why your car is is fast
One thing I noticed is how the WBO2 on the dyno reads quite a bit different than what I read on my WBO2. See attached. I sure don't trust theirs, my car runs like a champ too, daily beaten 
EDIT: IGNORE THE FIRST PARAGRAPH. Sounds like your plumbing is OK, since you need to have the wastegate working with the "valve control". You're reading boost pressure from the right spot from what I know.
Last edited by mdpalmer; 12-29-07 at 08:00 PM.
12-29-07, 08:28 PM
#90
No I don't get any boost spikes. No my AFRs are not lean, above 11.5 is when they start to be considered too lean from what I have read. Your AFRs are all over the place, mine stays at a nice flat line, on the PLX R-500 (well flat compared to yours).
12-29-07, 08:41 PM
#91
Click here for a picture of one of my wideband AFR data logs. Make sure you look at the enlarged picture, it's big and may get resized on your computer screen, zoom in.
01-30-08, 08:58 PM
#94
much props man. you're a great driver I'm really interested in seeing you shift. maybe next time you can shoot a video going down the track from the inside?? 
how do you launch and when do you shift??
that hp does seem very low at 19psi. i made 338whp @ 14psi. still very impressive.
I'm really interested in seeing you shift. maybe next time you can shoot a video going down the track from the inside?? how do you launch and when do you shift??
that hp does seem very low at 19psi. i made 338whp @ 14psi. still very impressive.
03-01-08, 10:36 PM
#96
thanks. I try to hold the revs around 6-7k, holding the clutch up right at the point before it grabs, and then I let out the clutch and go full throttle to launch, I don't drop the clutch, I let it out a little slow, I think it helps the boost build as I leave the line, this way the car doesn't jump and bog like it often does if you drop the clutch too fast.
I was usually shifting at about 7500 rpms, no higher than 8k. The short shifter helps a lot, I use to miss 3rd when trying to shift into third real fast.
I was usually shifting at about 7500 rpms, no higher than 8k. The short shifter helps a lot, I use to miss 3rd when trying to shift into third real fast.
03-03-08, 08:46 PM
#97
Banned. I got OWNED!!!
Join Date: Mar 2008
Location: Russia
Posts: 3
Likes: 0
Received 0 Likes
on
0 Posts
03-21-08, 03:22 PM
#99
fighting terrorists
Join Date: Mar 2008
Location: el paso tx/germany/iraq=(
Posts: 108
Likes: 0
Received 0 Likes
on
0 Posts
yeah same thing i was thinking stock engine!!!!! wow those are the exact times im looking for !!!! hopefully i will be there soon thanx for the inspiration!!!!
