my 3300 lb drag car with a 454 and s475 1.32 a/r makes more power at 5lbs of boost over 12lbs I no now it’s to small it’s on e85 with no IC would spraying 50/50 meth/water help make more power? I would like to run 10lbs and pick up 100hp ! Oh it’s has fast EFI

 

“More power” backed up by dyno numbers or just seat of the pants meter? That compressor even in a box Borg cast wheel configuration is good to well over 40lbs and still within its MAP. And there wasn’t much information at all on the car given to make a fair judgment on your assumption.


Carb? FI ? Timing based on boost? There’s way to many factors that it just makes more power At 5lbs than it does at 12lbs.

 

Based on it runs more mph at 5lbs it has fast efi, 24* at boost, the AIT at 10lbs are over 250.

 

If its a even a mild built 454 its probably eating that turbo up. I wouldnt expect it to be that bad at 10 lbs though.

I will say that timing is way too low for a 454. But with IAT that high Im NOT gonna say give it more.

Water meth will help. But cant say how much heat it will remove. Every setup is different.

 

A larger compressor may well help your IAT, when i had an s472 on a 472" ford my iat were well above 200°. After i went to the s480 my iat never climbed above the 150° range. Is there a reason not to run an intercooler?

You need to do a lot more reading, and not give input on subjects if your knowledge isn't up to snuff. Your making a blanket statements that are outright wrong. Turbos do not just happily produce their maximum psi at any rpm and any displacement. Please do not spread misinformation.

 

Just had a thought. There is a IAT to fuel chart. Default is pretty low. So after X iat temp it over fuels.
You can extend the chart out into higher IAT range so it doesnt do this.
You should be able to see this in a Log.
Had a friend with a non intercooled v6 with 300ish IAT and the car would just lay over at 1/8mile because of this.

 

The motor NA makes 400 RWHP

 

I will definitely look into that IAT chart! My be a easy fix to picking up power at 10lbs! Thanks

 

need more turbo period

learn how to read compressor maps and size compressors.....search

 

I couldn’t agree with you more! I did not build the setup my post states s475 to small I am just asking for help not critazizim !

 

Are you tuning it yourself? With the info given I don't know that anyone can give you the definitive answer you want. With good fuel, and a proper tune, 250* iat's aren't a deal breaker, but the with the 475 you may not make any more hp. Cooler iat's aren't going to hurt so give it a try.

 

I think with only going 5 more lbs I will try some things mentioned and see if it picks up before I call Jose at FI for a 91 mm billet and race cover!!!

 

dont get caught up in just the compressor. The exhaust side is gonna be a restriction for that size motor.
I would call him and just tell him what your goals are and let him tell you what you need to achieve it.

Keep us updated!

 

Will do!!!

 

Misinformation? I said that MAP is good to well over 40lbs. Did I state it was good to run that much in his particular setup? No.

But you’re telling me that 454 draws more air than the 15 Liter engine that particular turbo was designed to run on, at 35-40lbs efficiently? All I was getting at with my questions I was asking, is that I found it odd that charger making less power at a measley 10lbs over 5lbs. So I asked questions. I did not say he should be able to run 40lbs on HIS setup.

 

Fact is the 15 liter motor it was design to make 40 lbs on was an engine that was done at 1800 rpm.
Its a whole different deal when you have another 4200 rpm of air flow. Nothing near the same mass flow.

Same reason a stock 6bt cummins turbo can make 50 lbs (if turned up). Take it off put it on a 350 sbc and it struggles.

 

I agree in general that turbo is on the small side for a 454. But… If it's only making 400 hp NA, it shouldn’t be tapped at 5lbs. Id find the problem before throwing a big $ turbo at it.


Have you checked it at 6-11lbs? Or did you just jump from 5 to 12? Have you double checked all your piping? Are you sure a BOV or something isn’t leaking at higher boost levels? Your symptoms could be caused by a large boost leak. A boost leak test rig is always a good idea. You can build one cheap. Search youtube for instructions.


Also where are you spraying the water/meth and how much? What are the IAT’s at 5lbs?


What kind of mph are you seeing at 5lbs VS 6lbs? What did it run at 12?

 

My response was out of sarcasm on the 15 liter engine. Haha Apologies. Could have worded it differently. But RPM and displacement consumption are HUGE factors on a MAP. But, even with all that, it’s just weird that 12lbs makes it struggle that bad creating IATs that high. 15-17- Maybe even 20lbs I could totally see it. But 10-12lbs? Idk I still don’t see the Pressure ratio of the compressor being that high at 12lbs to struggle THAT bad and be a noticeable difference. Seems lacking. Unless it was a 550-600hp N/A motor. Ok. You bet, that charger isn’t going to suffice at all. But I could be totally wrong. Who knows.

 

Well that’s why I posted on here I think I can get a little more out of this Turbo I don’t have a spray system yet that’s one of my questions I asked if it was worth it runs 2 mph in the 1/8th faster at 5lbs I only have 10 or so passed on it and haven’t logged it yet at 5 lbs but I am going to check for a boost leak! Thanks