Are you going straight pipe or working in the cats and reso?
Bolt on turbo kit (8 Viewers)
- Thread starter scottryana
- Start date
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no cats but muffler and resonator.
ahh i see, im in cali so it would be hard with no cats.
Another question, do you have and cooling issues? I spoke to Joey way back when i ordered he turbo, he said best would be the Ron Davis rad but i already have a brand new rad. I did get my hand on a aux fan so I think that would help.
alia176
SILVER Star
I have a brand new Koyo alum radiator and I often see temps above 210deg (and holding) as summer is approaching. The aux fan won't do bubkus for radiator cooling, only for a/c condenser. The fan clutch is what pulls fresh air in through the radiator and mine is 15,000 CST with the blue clutch and with timing advanced (on the clutch, not the engine).
Just for S&G, I'm going to pull the hood off and drive around on a hot summer day to see if the actual coolant temp gets lowered as the under hood temps is very high.
I don't want to be a business consultant because I'd have to charge so much but perhaps your energy should be spent on getting the product logistics ironed out. Probably would satisfy more people in the long run
Yea, i got a koyo also, and bought the blue fan clutch from Joey, not sure what cst he put in that since its off his website now.
CJK
SILVER Star
It depends On how you define “best”
Technically it will build boost quickest with the least exhaust back pressure (more open = more good), but you risk overboosting and “finding the weak link” in your system (which costs $$$$ to fix).
It is safest to use OEM exhaust as it was designed, but you’re definitely not achieving full power potential of system.
CJK
SILVER Star
No cooling issues with OEM radiator but blue fan clutch and like 20K fluid (roars like a lion on start-up).
I’m installing hood louvres to improve ventilation of engine bay.
These cars were known to have elevated underhood temps when NA (like Jeeps), so adding a turbo likely exacerbates the problem, but unknown by how much or what the downstream effects are. I do know that excessive underhood heat will decrease life of all the plastic and rubber parts in engine bay (wires, hoses, belts, etc.). I also know I’d rather do preventative work on my time schedule (installing hood louvers) than be broken down or engine fire due to fuel lines or wires deteriorating (because I’m not inspecting super regularly).
Seems like most dudes (maybe some
Chicks own the kit) are running turbo without adding additional venting to engine bay and not having problems, so adding louvers is not a must-do.
If you live in a hot climate, It’s something to be aware of.
I would go 2.75. Turbo will appreciate less restriction
- Thread starter
- #5,930
I wouldn’t
Not unless you've got some engine management tricks up your sleeve. The kit is designed around 2.5" or factory exhaust and anything that makes the turbo spool faster is likely to result in a lean condition. This is what breaks engines.
Not saying the 0.25" is going to be a huge factor or that your motor will immediately blow up, but if reliability matters at all and you're not changing engine management (stand alone computer), not a good idea to force a lean condition by spooling the turbo before the computer goes closed loop and starts dumping fuel. This is specifically why this turbo size/spec was selected for the kit.
CJK
SILVER Star
Interesting, thanks for explaining. I didn’t even think of that (not that I’m any expert).
So essentially the stock engine management is slower at detecting lean then adjusting fueling than the turbo is at building boost (if no exhaust back pressure)?
Any particular reason why or is that issue prevalent anytime you change NA -> FI without flashing the ECU or changing EMS?
- Thread starter
- #5,934
You're dealing with what is close to 30 year old technology, the O2 sensors used in the 80 series are narrow band not wide band, and even think about the computer the truck is running. Compare a home PC to one from 30 years ago. The technology just wasn't there to have quick response to a wideband O2 and adjust fueling fast enough, so Toyota used what is called open loop fuel control where when you get in a place on the load table it stops reading the O2 sensor and in the OBDII engine creates a very rich condition which is what is being taken advantage of to run forced induction on this engine.
CJK
SILVER Star
1) Makes sense regarding CPU limitations of 30 year old tech. With the pace of innovation, crazy to think CDs were literally cutting edge at the time.
2) Thanks for explaining about fuel control, I actually didn’t know that so it’s cool to understand more about why this kit works as designed. It’s still super cool you designed this turbo system.
I had nothing more than surface knowledge of turbos so I read Forced Induction Performance Tuning A Practical Guide to Supercharging and Turbocharging by A. Graham Bell to learn more. With that said, there’s still a massive gap between reading that book and your knowledge so thanks for explaining. Super fascinating to nerd out on.
Is this why I see the following: I accelerate at a modest pace but on road conditions that require boost (hill, highway speeds, etc.), instead of landing at 14.7 or so AFR, I see 12 or so and it persists there until I get off the throttle for a significant period of time (several seconds). At this point, the AFRs go super-lean and then come back to the 14 range.
- Thread starter
- #5,937
Correct, the narrow band and computer can’t correct fast enough to keep a set air fuel ratio so what Toyota (and most manufacturers of the time) did was have what is called closed loop fueling and open loop fueling. Closed loop is moderate load, moderate throttle driving that uses the O2 sensor, load table, fuel table and short term and long term fuel corrections to maintain the narrow range around 14.5:1-15:1. When you’re outside of that load table the truck is on open loop where it is basically going very rich with no feedback from the O2 sensor, it’s just programmed to go much richer than is needed. We are using that open loop fueling to fuel the extra air from the turbo.
What you are seeing is totally normal, and when you say it goes super lean that is also very normal because you have gotten off the throttle. Off load lean conditions are not a problem. Go coast down a steep long hill and you’ll see 20:1
alia176
SILVER Star
Summer is here in the Southwest and my temps are now hitting 224deg and the a/c is cutting out at 222degF. So, I drove to work with the hood removed and curious to see if that helps.
I have the hood louvers, 15k CST and a new Koyo alum radiator. Before I reinstall the hood, I'll remove the rubber seal on the cowling and space up the rear of the hood by 1/8" to see if that helps.
CJK
SILVER Star
If that does work, then you know "given enough air flow, the engine will stay cool". How much airflow is the BIG question...
How much air flow are you getting through those louvers in that position? I think raising rear of hood is low cost/low effort project that may help.
I just installed the center louver section from the Trackspec kit, which is right on top of the motor. Since I'm in NorCal, I don't worry about rain (
) and will make sure sensors on top are adequately waterproofed.Driving home yesterday outside temps were mid-80s, coolant stayed 190-194 (from OBDII). I don't have a way to measure airflow, but there's a lot of airflow through the louvers, so it seems like it's working.
