12a CarTech drawthrough HELP!!
02-03-09, 10:07 AM
#76
I DONT plan on running water/meth injection. I will be using a CarTech drawthrough setup with a IHI RHB6 turbo. I might try venturing up to 9-10 psi once I have some 91 octane in the tank.
It feels like this thread is becoming a debate on forced induction methods and advantages/disadvantages to each. I find this very interesting, but, seems to be leading the focus of this thread back and forth.
The ONLY area of interest I have at this time is TIMING.
My 4 options as I see them now:
(1) Lock timing at 10* w/ sync’d L and T
(2) Lock Timing at 15* w/ sync’d L and T
(3) Lock Timing at 10* L w/ 5-10* split
(4) Leave mech advance active, set -5* L w/ 5-10* split
NOTE: all have vacuum advance disabled...
Anyone have any input on this?
It feels like this thread is becoming a debate on forced induction methods and advantages/disadvantages to each. I find this very interesting, but, seems to be leading the focus of this thread back and forth.
The ONLY area of interest I have at this time is TIMING.
My 4 options as I see them now:
(1) Lock timing at 10* w/ sync’d L and T
(2) Lock Timing at 15* w/ sync’d L and T
(3) Lock Timing at 10* L w/ 5-10* split
(4) Leave mech advance active, set -5* L w/ 5-10* split
NOTE: all have vacuum advance disabled...
Anyone have any input on this?
02-03-09, 11:02 AM
#77
Your 100% correct! Someone tried to slap my pe-pe and I felt I had to retaliate and got completely off course.
No one will agree on one set way to do what your asking. Best bet would be to do some serious reading on the Web and make the decision on your own.
If you’ve ruled out meth IMO you’ve ruled out all options but 1,3. It’s up to you.
I’d run 6psi locked timing at 10* At those boost and timing levels it doesn’t really matter if your sync or split the L&T. This is why all the old school tuners did it. It’s overly safe….and a waste of time if U ask me.
Seems for power gains your going through a lot of trouble for 30hp? Could have gotten close th that with a header and intake. Or a stock 13b swap.
Good luck what ever you decide. I promise I’m done debating on your thread. If anyone would like to continue in PM’s bring it on!
No one will agree on one set way to do what your asking. Best bet would be to do some serious reading on the Web and make the decision on your own.
If you’ve ruled out meth IMO you’ve ruled out all options but 1,3. It’s up to you.
I’d run 6psi locked timing at 10* At those boost and timing levels it doesn’t really matter if your sync or split the L&T. This is why all the old school tuners did it. It’s overly safe….and a waste of time if U ask me.
Seems for power gains your going through a lot of trouble for 30hp? Could have gotten close th that with a header and intake. Or a stock 13b swap.
Good luck what ever you decide. I promise I’m done debating on your thread. If anyone would like to continue in PM’s bring it on!
02-03-09, 11:17 AM
#79
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There are some very worthwhile timing discussions in the single turbo section. Bear in mind, though, that most of them have twice your power or more. 
Here's a nice thread on split:
https://www.rx7club.com/single-turbo-faq-122/how-many-run-no-split-timing-325400/
Here's a nice thread on split:
https://www.rx7club.com/single-turbo-faq-122/how-many-run-no-split-timing-325400/
02-03-09, 01:36 PM
#81
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Of course you wouldn't use their exact numbers. It gives you an idea of how it works, though.
Seems like most of the carbed turbo guys like to lock their distributors. If you do that, I would set it to 10 degrees on leading with a smaller split, maybe 5 degrees. That will give you a nice safety margin, and you won't have to run as rich to compensate for aggressive timing.
Seems like most of the carbed turbo guys like to lock their distributors. If you do that, I would set it to 10 degrees on leading with a smaller split, maybe 5 degrees. That will give you a nice safety margin, and you won't have to run as rich to compensate for aggressive timing.
02-03-09, 02:43 PM
#82
Your 100% correct! Someone tried to slap my pe-pe and I felt I had to retaliate and got completely off course.
No one will agree on one set way to do what your asking. Best bet would be to do some serious reading on the Web and make the decision on your own.
If you’ve ruled out meth IMO you’ve ruled out all options but 1,3. It’s up to you.
I’d run 6psi locked timing at 10* At those boost and timing levels it doesn’t really matter if your sync or split the L&T. This is why all the old school tuners did it. It’s overly safe….and a waste of time if U ask me.
Seems for power gains your going through a lot of trouble for 30hp? Could have gotten close th that with a header and intake. Or a stock 13b swap.
Good luck what ever you decide. I promise I’m done debating on your thread. If anyone would like to continue in PM’s bring it on!
No one will agree on one set way to do what your asking. Best bet would be to do some serious reading on the Web and make the decision on your own.
If you’ve ruled out meth IMO you’ve ruled out all options but 1,3. It’s up to you.
I’d run 6psi locked timing at 10* At those boost and timing levels it doesn’t really matter if your sync or split the L&T. This is why all the old school tuners did it. It’s overly safe….and a waste of time if U ask me.
Seems for power gains your going through a lot of trouble for 30hp? Could have gotten close th that with a header and intake. Or a stock 13b swap.
Good luck what ever you decide. I promise I’m done debating on your thread. If anyone would like to continue in PM’s bring it on!
02-03-09, 04:30 PM
#83
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Widebands are great for WOT tuning, but they don't react to spikes like a narrow band will. Like in my application I used to get a lean spike on cruise and the wideband doesn't see it at all, but the narrow band does. I run the atuometer procomp ultralight wideband and narrowband.
Any display latency with your wideband is either because its a cheap unit, or your display is laggy. I run a TechEdge WB setup for tuning and when its in my FD or SC300 TT, I wire it to the Haltech so I can log AFRs during runs. At a 100 ms sampling rate, I see changes in AFR every sample - every 100 ms. I can provide the datalog if you'd like to take a look.
I have no experience with draw through other than extensive study, but I do have lots of experience with boosted rotaries and EFI. I run 23 psi of boost on 91 octane - Cali gas - and methanol. This is not my "occasional" boost setting...this is my minimum boost setting for the street. I also run 12 degrees of advance and 10 degrees split timing at 23 psi...which is still very conservative. AFRs are in the mid 11 range. My fuel mix is 78% gas and 22% methanol starting at 15 psi. Note that my engine is a half-bridgeported 13B-REW, with a Turbonetics T66, 1.0 turbine A/R with a divided flange. Last dyno run was in February, on 100K mile rotor housings and 4 degrees advance at 23 psi, and I made 450 rwhp. It now has brand new housings and 12 degrees, should be closer to 500 now.
I suggest you take a look at the auxiliary injection section of this forum and see what people are doing. BDC has just ditched his intercooler in favor of meth injection and is having great success.
Anyways sorry to threadjack, just trying to clear up what I saw as misinformation.
02-03-09, 04:46 PM
#84
I don't have any proff, but the reason teh drawthrough evolved to blowthrough was because of the heat issues. Blowthrough's just run cooler. Read all my old threads I've explained it 10000 times. And Percent is runninf 5*ATDC and he's drawthrough supercharged...
go with (3) Lock Timing at 10* L w/ 5-10* split
go with (3) Lock Timing at 10* L w/ 5-10* split
02-03-09, 04:56 PM
#86
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I'm not trying to correct you Hyper4mance2k, but for the sake of knowledge...
Any display latency with your wideband is either because its a cheap unit, or your display is laggy. I run a TechEdge WB setup for tuning and when its in my FD or SC300 TT, I wire it to the Haltech so I can log AFRs during runs. At a 100 ms sampling rate, I see changes in AFR every sample - every 100 ms. I can provide the datalog if you'd like to take a look.
You underestimate the abilities of methanol for a boosted rotary.
I have no experience with draw through other than extensive study, but I do have lots of experience with boosted rotaries and EFI. I run 23 psi of boost on 91 octane - Cali gas - and methanol. This is not my "occasional" boost setting...this is my minimum boost setting for the street. I also run 12 degrees of advance and 10 degrees split timing at 23 psi...which is still very conservative. AFRs are in the mid 11 range. My fuel mix is 78% gas and 22% methanol starting at 15 psi. Note that my engine is a half-bridgeported 13B-REW, with a Turbonetics T66, 1.0 turbine A/R with a divided flange. Last dyno run was in February, on 100K mile rotor housings and 4 degrees advance at 23 psi, and I made 450 rwhp. It now has brand new housings and 12 degrees, should be closer to 500 now.
I suggest you take a look at the auxiliary injection section of this forum and see what people are doing. BDC has just ditched his intercooler in favor of meth injection and is having great success.
Anyways sorry to threadjack, just trying to clear up what I saw as misinformation.
Any display latency with your wideband is either because its a cheap unit, or your display is laggy. I run a TechEdge WB setup for tuning and when its in my FD or SC300 TT, I wire it to the Haltech so I can log AFRs during runs. At a 100 ms sampling rate, I see changes in AFR every sample - every 100 ms. I can provide the datalog if you'd like to take a look.
You underestimate the abilities of methanol for a boosted rotary.
I have no experience with draw through other than extensive study, but I do have lots of experience with boosted rotaries and EFI. I run 23 psi of boost on 91 octane - Cali gas - and methanol. This is not my "occasional" boost setting...this is my minimum boost setting for the street. I also run 12 degrees of advance and 10 degrees split timing at 23 psi...which is still very conservative. AFRs are in the mid 11 range. My fuel mix is 78% gas and 22% methanol starting at 15 psi. Note that my engine is a half-bridgeported 13B-REW, with a Turbonetics T66, 1.0 turbine A/R with a divided flange. Last dyno run was in February, on 100K mile rotor housings and 4 degrees advance at 23 psi, and I made 450 rwhp. It now has brand new housings and 12 degrees, should be closer to 500 now.
I suggest you take a look at the auxiliary injection section of this forum and see what people are doing. BDC has just ditched his intercooler in favor of meth injection and is having great success.
Anyways sorry to threadjack, just trying to clear up what I saw as misinformation.
thats what happened to my buddies setup that is...
oh and 450 rwhp is low for that size turbo @ that much boost on a 13B rew motor.. there are guys makin 500 rwhp using smaller turbos on a non ported motor. you should check out the single turbo section
02-03-09, 05:15 PM
#88
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until the meth nozzle clogs=6 blown apex seals..
thats what happened to my buddies setup that is...
oh and 450 rwhp is low for that size turbo @ that much boost on a 13B rew motor.. there are guys makin 500 rwhp using smaller turbos on a non ported motor. you should check out the single turbo section
thats what happened to my buddies setup that is...
oh and 450 rwhp is low for that size turbo @ that much boost on a 13B rew motor.. there are guys makin 500 rwhp using smaller turbos on a non ported motor. you should check out the single turbo section
I thought I might get some **** about my dyno figure. I'm happy with the number. I don't run my car on a DynoJet and get nice big EGO numbers, I run on a Superflo dyno. Did you miss the part about running 4 degrees timing at 23 psi on that dyno? Those were pump gas timing settings, of course the readings would be lower.
Sure there are those making insane numbers on smaller turbos. How long do their engines last? Are they running pump gas, especially 91 octane? I don't think so. Reliability trumps maximum power output, as least that's my philosophy.
What's your setup, by the way?
02-03-09, 05:22 PM
#89
I went this route because of cost and availablity.
If I am going to get any more complicated it will involve an engine transplant.
02-03-09, 06:03 PM
#93
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IMHO, the "proper" way to get your timing dialed in is to start with 10* as Hyper recommended, get yourself two EGT probes and place them at each exhaust port in your manifold. Watch the EGT settings and increase timing gradually from there, using a wideband to keep an eye on the AFRs...the more you advance the timing, the richer the mixture will become. Each engine is different so this is the only way to dial in that timing. Run nothing but premium fuel too...even at 6 psi, 87 may be too risky. Its not worth the .10 savings per gallon to kill an engine.
The way that intake manifold looks, you're gonna get funky fueling to both rotors...with a log-style intake manifold like that, the outer ports are going to get less fuel than the primaries...enough to affect the EGT and wideband settings. You may have to run richer than ideal to keep everything happy.
The way that intake manifold looks, you're gonna get funky fueling to both rotors...with a log-style intake manifold like that, the outer ports are going to get less fuel than the primaries...enough to affect the EGT and wideband settings. You may have to run richer than ideal to keep everything happy.
02-04-09, 12:31 AM
#95
The good and the bad
It RUNS!!! ... kinda
Got it running tonight. Used an old carb which I think needs to be rebuilt... it ran pretty rough. Might stick my Carter carb back on it as I know it ran OK.
I had to cut my warm up short as I have a massive oil leak. I was afraid it was my oil return, but, looks like my new Mazda OEM oil pan gasket split... GAH, I must have over-tightened. The Anti-Christ of an oil pan strikes again... DAMN I hate taking that thing off. I think I'm gonna replace it with a Black Dragon gasket as they have a metal "insert" to prevent splitting. That's what I had before and it worked great.
Under idle/no load, will you get positive pressure? Or just vacuum? Even when revving it...
Does the car need to be under load to build boost?
Got it running tonight. Used an old carb which I think needs to be rebuilt... it ran pretty rough. Might stick my Carter carb back on it as I know it ran OK.
I had to cut my warm up short as I have a massive oil leak. I was afraid it was my oil return, but, looks like my new Mazda OEM oil pan gasket split... GAH, I must have over-tightened. The Anti-Christ of an oil pan strikes again... DAMN I hate taking that thing off. I think I'm gonna replace it with a Black Dragon gasket as they have a metal "insert" to prevent splitting. That's what I had before and it worked great.
Under idle/no load, will you get positive pressure? Or just vacuum? Even when revving it...
Does the car need to be under load to build boost?
02-04-09, 10:10 AM
#97
Cartech Drawthu
Hey Beargogerr,
Been following this increasingly popular thread. Just some advice from a fellow Cartech Drawthru owner.
The way I understand it, this locking of the dizzy at 10 degree advance is to eliminate the possibility of the timing being advanced to the point (through some sort of mechanical failure) during boost conditions to precipitate preignition and destroy the engine.
I never did this because at the low boost pressures we're using I think this scenario is unlikely and there are other more important precautions to take. I also feel disabling the centrifugal and vaccuum advance affects your fuel economy and off boost driveability. One time the hose to the vaccum port on the dizzy came off and the car felt immediately different at low rpm, throttle response was delayed.
I think tuning with a wideband sensor to ensure you have a rich fuel mixture during boost is the most important thing to ensure no preignition. If you're using the Holley 8007 carb I can give you some specs on jets and secondary metering plates to try.
Also using the highest octane gas available doesn't hurt.
Been following this increasingly popular thread. Just some advice from a fellow Cartech Drawthru owner.
The way I understand it, this locking of the dizzy at 10 degree advance is to eliminate the possibility of the timing being advanced to the point (through some sort of mechanical failure) during boost conditions to precipitate preignition and destroy the engine.
I never did this because at the low boost pressures we're using I think this scenario is unlikely and there are other more important precautions to take. I also feel disabling the centrifugal and vaccuum advance affects your fuel economy and off boost driveability. One time the hose to the vaccum port on the dizzy came off and the car felt immediately different at low rpm, throttle response was delayed.
I think tuning with a wideband sensor to ensure you have a rich fuel mixture during boost is the most important thing to ensure no preignition. If you're using the Holley 8007 carb I can give you some specs on jets and secondary metering plates to try.
Also using the highest octane gas available doesn't hurt.
02-04-09, 10:11 AM
#98
And I think I need to adjust my swing arm linkage for my wastegate as it sounded like it was open when I warming it up. Either that or a massive exhaust leak.. LOL
Man I hate delays.... GRRR
Ordered replacement oil pan gasket last night. Should be here in a couple days.
FYI... before my car started bleeding to death, it had just reached temp. The vacuum side of the intake was VERY cold... I can see why icing up is a concern. Even when the car had warmed up the pressure side of the intake was very cold as well. We'll see how things feel when under boost.
I plan on throwing my Carter on the setup once I replace the oil pan gasket AGAIN. Once I get things warmed up I will set the timing... Im running it at OEM timing with the vacuum advance line DISCONNECTED atm.
Man I hate delays.... GRRR
Ordered replacement oil pan gasket last night. Should be here in a couple days.
FYI... before my car started bleeding to death, it had just reached temp. The vacuum side of the intake was VERY cold... I can see why icing up is a concern. Even when the car had warmed up the pressure side of the intake was very cold as well. We'll see how things feel when under boost.
I plan on throwing my Carter on the setup once I replace the oil pan gasket AGAIN. Once I get things warmed up I will set the timing... Im running it at OEM timing with the vacuum advance line DISCONNECTED atm.
02-04-09, 10:28 AM
#99
Thanks jim_chung, I've actually been referred to your posts more than once as being an "seasoned" drawthrough 7 owner.
I do have a wideband.. i installed it just hours before starting it last nite.
You list several things you WOULDN'T do with ignition, but, what would you recommend for timing? what are you running? How much boost are you running?
The holley 390 cfm carb (8007) i'm running has the optional secondary metering BLOCK (http://store.summitracing.com/partde...?part=HLY-34-6). But, I would LOVE some starting points for tuning the carb. I'm thinking I need to rebuild it anyways, so, it will be in piecing very shortly.
Does anyone know WHICH Holley RENEW kit is for these carbs? Damn, they vary from $30-95
I do have a wideband.. i installed it just hours before starting it last nite.
You list several things you WOULDN'T do with ignition, but, what would you recommend for timing? what are you running? How much boost are you running?
The holley 390 cfm carb (8007) i'm running has the optional secondary metering BLOCK (http://store.summitracing.com/partde...?part=HLY-34-6). But, I would LOVE some starting points for tuning the carb. I'm thinking I need to rebuild it anyways, so, it will be in piecing very shortly.
Does anyone know WHICH Holley RENEW kit is for these carbs? Damn, they vary from $30-95
02-04-09, 10:46 AM
#100
I'm thinking the Holley Renew kit:
http://store.summitracing.com/partde...5&autoview=sku
or the Quick Fuel one:
http://store.summitracing.com/partde...5&autoview=sku
but, I will also need the gaskets for the secondary metering block... Should I just get a rebuild kit for the 4150 carb than or order a rebuild kit for the 4160 and...
http://store.summitracing.com/partde...5&autoview=sku
http://store.summitracing.com/partde...5&autoview=sku
or the Quick Fuel one:
http://store.summitracing.com/partde...5&autoview=sku
but, I will also need the gaskets for the secondary metering block... Should I just get a rebuild kit for the 4150 carb than or order a rebuild kit for the 4160 and...
http://store.summitracing.com/partde...5&autoview=sku