General Supercharger Thread

Down to a 2" if you're insane like @Mdl or @Fastlane47, but one step down to a 2.2" would probably be the place to start like Silver said. I'd also consult with whoever tuned your truck and see what they think about increasing the boost.

 

Did you figure out your lean condition. Just need to be cautious.

 

How many meth miles would you say that has? Was it a 50/50 mix?

 

It was -40 rated winter windshield washer fluid, so approximately 50/50 I believe. The blower has around 20000 miles on it, but water/meth was setup to only spray at heavy throttle.

 

Uh.. I did not but I just got armyoffroads old Prospeed upgrade so fingers crossed it fixes everything… if it doesn’t I have no clue what could be the culprit. Gonna drill holes in my basket with a new fuel pump (267 instead of the 274)

 

I don't remember. Possibly.

I'll look through my pictures

 

If you use the 267 walbro 450 you don't need to drill holes. Also the deutchwerks dw300 fits in there too. @e30cabrio went through it with his 450 then switch to the dw300.

 

I strongly suggest avoiding Walbro. Numerous tank drops are my proof.

Lol

 

What’s the reason being? I’m hardwiring my pump

 

Several direct from Walbro failed, "customer service" is a joke. Expensive, DW just work.

 

What made you need to drop your tank? Fuel pressure loss? You’re making me scared now man!

 

I and others mentioned all these issues in the other thread....

 

To remove the pump the tank must be dropped.

 

Yeah, I know.. I just thought it was because of the 274. Hopefully I have better luck

 

Yeah I get that, sorry asked it wrong.. did it just completely fail or were you losing fuel pressure?

 

Yes, he was having fuel pressure issues. It seems it's hit or miss with walbro. Myself and a few others are running them but others didn't work out so well.

 

None gave over 20lbs, I'm unaware of anyone having issues with DW.

I'd suggest not installing the Walbro, but all I can do is tell my experience. Maybe you get lucky.

 

Well wouldn't ya know truck runs much better without the Cat chunks blockage. Damn thing screams now without the 2 front cats and just the secondaries. Have a little bit of exhaust leakage on pass side between first gutted cat and second cat- I cut that shit to break up the passenger side cat to match driver side so it ghetto rigged together temporarily. With spacers on rear O2s no codes either. My tuned was fucked for I was richening MAF per datalogs for lean condition up high. Now I'm able to tune dead nuts, leaning out MAF volts to PE. Thank god that's over, can't wait to run the SPD DPs and tune

 

Would be tricky to answer. Some of those items can be calculated while others would need to be simulated or determined by trial and error swap, especially if there are some performance inter-dependencies.

TBs usually have a CFM/HP rating. Rule of thumb on TB sizing seems to be gains had up until matching the blower snout with diminishing gains after that. Ignoring physical envelopes and MAF scaling limitation, I haven't seen anything restricting intake size or length. If you account for volume general rule is as volume increase as does HP on the big end and this include manifold spacers. Beside removing restrictions I've not seen other precedence of upgrades on the intake side. I haven't seen much on heads and porting even in other posts. Aside from material and manufacturing choices, stock design is probably optimal in most areas for our given power levels.

"Optimal" exhaust diameter can be calculated using a formula with consideration for power goal. Can also be tested following Engine Master test protocol. It is also a trade off of power for the big end but sacrifice on the little end. Problem here is not all exhaust products are created equal and most of your single out exhausts will fall short of the calculated sizes. Free flowing headers and exhaust have other benefits that wont show on a dyno as well.

 

https://youtube.com/shorts/Ah0Ia0S_9N8?si=V84bnc4WvVopmgfg

 

I can hear Banks screaming now:
https://youtube.com/shorts/1cTLl3c5jzk?si=RambYGFQDe4KIdYh

 

All I know is I have a true dual 3 inch exhaust and deleted about 4ft of it and it reduced pressure by 2psi. This enabled me to go with @snivilous 2.0 pulley on the tvs1900. I max out at around 14psi. This is still crazy parameters for the stock setup.

 

Like @Mdl suggested, if you’re going 267 I think you should not drill holes. My understanding is that would defeat the purpose of using the 267 which is to use the jet pump. Drilling holes in the basket I think is the ghetto solution for filling the basket more quickly if using the 274. Or buy the DW300c kit for the tundra, which seems to be plenty of pump for most of us.

 

Dual 3" is enough if you go by the calculators though I didn't see any calculate length or account for any other exhaust features.

There are several calculators, charts and tutorials but the common element is they all seem to focus on targeting an exhaust velocity below a threshold. Unfortunately they don't all clarify where they measure HP so I just assumed crank #s unless they stated otherwise. They all get you fairly close to the same #s.

Here is one with charts and Summit racing videos: https://m.roadkillcustoms.com/determine-proper-exhaust-tubing-size/

Easy Way To Estimate: Your intake system needs to flow 1.5 CFM per engine horsepower, and your exhaust system needs to flow 2.2 CFM per engine horsepower.

 

I recall seeing that chart before. According to the chart, the factory exhaust is woefully inadequate for a SC tundra. However, as @e30cabrio noted, it seems to only be inadequate at higher rpm. Assuming 5k rpm is infrequent, I suppose the factory piping would be sufficient? Note I said piping, not necessarily muffler.

Also, how does a positive displacement blower affect those sizing requirements? Or does it even affect it at all? I would think that having an air pump pushing air through the system might make it more acceptable to use smaller piping? The volumetric efficiency of the motor can go past 100% using a PD blower whereas a standard street car is 63-80% volumetric efficient (per an performance engine website I was perusing the other but would have to search for). It kinda makes sense in my head but that may not be the reality of it. I think the smaller than optimal piping would add restriction to the system and you would see higher boost but would it really kill power as opposed to simply making that same power in a less efficient manner? This supposition would be supported by @reywcms seeing a drop in boost when installing the full dual 3” exhaust. No he didn’t dyno it, but it didn’t appear to be down on power either.

 

are there any negatives if I were to drill holes just to be sure?

 

Walbro pump and holes here no issues..

 

Maybe this will give you a better idea of what the jet pump is doing, and what effect drilling holes in the canister will have. The jet pump is there to keep the basket full of fuel and the pump submerged even if the fuel level in the tank is quite low as it sucks in fuel from the very bottom of the canister. Adding holes to the basket will allow the fuel to spill out of the basket at lower fuel levels and make it harder to keep the basket full of fuel for the pump to both suck up and be cooled by. https://m.youtube.com/watch?v=n0gAlkV2xGc&pp=ygUURnVlbCBiYXNrcnQgamV0IHB1bXA=

 

That's what I ran into with an aeromotive pump years ago.

 

That video isn’t exactly the same situation since he’s using a separate fuel pump to fill the basket. In our setup it’s more of a venturi effect pulling fuel into the basket. It’s still a helpful visual though I thought. I wouldn’t say you can’t drill holes, many people do it seems. I’ve just seen it described as not the “right way” by Matt Smith who is pretty good with this stuff.