Phenolic Blower Spacer

[bonneville dan-o]

I'm thinking about installing a 1/4" thick phenolic blower spacer in my 00 ssei, but i have a few questions first.

since it will be raising the supercharger 1/4" plus the extra supercharger gasket will my stock fuel rail still work with this setup or will i have to get injector spacers?

how much will i really gain? since it blocks off the coolant passages to the s/c and the throttle body i know it will lower Kr but will it really gain me much?

I'm taking the Bonnie on a 3000 mile round trip to Texas and back in September to watch my girlfriend graduate from boot camp, so i don't want to do anything that will negatively effect my gas mileage. will it effect the mileage at all?

any help is appreciated

[SuperSLE]

1/4" isn't worth it IMO. Now if you go with something like 1"-1.5" Then yeah, it will definately help keep blower temp down.

You would have to use the spacers no matter how much you raise it. Stock rails only work for the stock setup with minimal clearance allowed.

Anyway, I ran a spacer for about a year and a half and there was a dramatic decrease in blower temps and cool down. In the winter time I went on a 5 hour trip non stop and when I got there I opened the hood and put my hand on the blower and it was cold. In the summer I could do the same, but it was hot, but I could keep my hand on it for an indefinate period of time and not get burned. Try that with a stock blower. It gets hot.

Perforamance gains....Well if you are racing it, maybe a tenth or two due to cooler temps, but not much more than that. Maybe some decreased KR due to that. Fuel mileage won't be affected at all.

[willwren]

This is another one of those things that will work to a degree (pun intended) but probably isn't worth the trouble and expense for the minimal gain.

[bonneville dan-o]

well i am going to do the lower intake manifold gaskets and valve cover gaskets in a week or so and figured that if i was gonna put one in this would be the time to do it since I'm already going to be in there.

[01bonneSC]

So the spacer blocking off coolant would RAISE supercharger temps? Thought the coolant actually cooled the SC?

[bonneville dan-o]

the coolant just helps the whole motor warm up quicker. actually heating up the s/c and throttle body and it helps for better idle at colder temps.

thats my understanding anyway

[willwren]

It depends on the situation. The inlet of the SC gets very hot at WOT. The coolant helps then, even at the track. But for short bursts of time. There is no evidence that overwhelmingly points either direction. Want me to pull my thermal analysis out again?

[bonneville dan-o]

It depends on the situation. The inlet of the SC gets very hot at WOT. The coolant helps then, even at the track. But for short bursts of time. There is no evidence that overwhelmingly points either direction. Want me to pull my thermal analysis out again?

maybe a thermal analysis would be helpful.

so if the coolant cools it down at WOT then why would you want to block off the coolant to the supercharger? that would mean this is a completely pointless mod.

would i be better off just getting a throttle body spacer?

[Pontiacdad]

The spacer would help in a heat soaked engine cruising around town.
The short bursts at the track is on a cool engine so the engine cooling system would help cool the rapidly spinning super charger.
Too many back to back runs at the track and this effect is lost as well.

[bonneville dan-o]

so for a daily driver that i beat on a little more than i probably should. is this worth the $100.

will i have problems with the S/C getting too hot when i kick it down?

[willwren]

$100? Count on quite a bit more. You have fuel injector spacers to buy, not to mention a longer belt. Probably other small items as well.

The hottest internal surface of an operating M62 or M90 blower is the inlet. This is without taking coolant flow into account. Some research was done in this area a few years ago by a team of Engineering students. Before I found their research, I did my own. I built a 3D model of an Eaton blower, constrained the lower flange at a nominal engine temp, and input ambient air (various temps) into it while simulating compression. The inlet got FAR hotter than the outlet, and soon after, I found their research. They came to the same conclusions I did. With my software (capable of thermal analysis), I did various modifications to the outlet to further decrease those temps (reducing sharp edges/turns), but there's just not much you can do to the inlet other than smoothing. I now port/polish superchargers based on these findings. The result? Unless you're intercooling, I suggest keeping the coolant passages. The only time it wouldn't help you is in the dead of winter or between track runs when you ice down the supercharger.

My research also included temperature strips on the supercharger for real-world comparison:






I don't recall my constrained temps for sure, but you can see the hot spot change between these two models:





Hot-lapping at the track or daily summer driving, the coolant temperatures are LOWER than the supercharger inlet surfaces.

[bonneville dan-o]

okay well scratch the spacer idea.

what about a throttle body spacer?

where did you get the red vacuum line? i like

[2000Silverbullet]

I blocked off both my TB coolant and SC coolant passages.
It runs about 20* cooler.
It doesn't have any effect once it heat soaks but I can cool it back down using the Meth injection.

The normal running SC surface temp for mine is 120 F
The 160 F coolant will heat it up.

The inlet of the SC will always be the hottest part if you have 500 F EGR gas injecting into it. Touch it and feel!

[bonneville dan-o]

ha no thanks i know its hot without touching it.

so i've been hearing two different things.

A. the coolant does heat up the supercharger

B. the coolant cools the supercharger.

so which one is it.

also i've been told that you can run your stock fuel rails with the 1/4" spacer without using injector spacers. but i've also been told you can't and you will have to use injector spacers.

has anyone had any first hand experience with this?

[2000Silverbullet]

When the SC is producing max boost under load I see after SC air temps of +200 F

Coolant will either heat or cool the SC depending on how hot the SC is and how hot the coolant is.

The stock injector rails are designed to position the inectors inside the LIM injector bores. If you raise the SC 1/4", the injectors will now sit 1/4" higher so the injector o-rings may not seal inside the bores.

[00Beast]

Actually, on the S2 L67, the injector bores are inside the heads.

[bonneville dan-o]

yeah but there is some clearance between the top of the S/C and the fuel rail.a 1/4" or more... so therefore you should in theory be able to get away without them.... but then the fuel rail will be closer to the supercharger heating up the fuel...

my brain hurts

[2000Silverbullet]

yeah but there is some clearance between the top of the S/C and the fuel rail.a 1/4" or more... so therefore you should in theory be able to get away without them.... but then the fuel rail will be closer to the supercharger heating up the fuel...

duh ya I meant the head bores.
Come to think of it you should be OK and I wouldn't worry about that small bit of heat on the fuel rail.

Go for it!

[willwren]

Keep in mind the Bullet's climate and everyday driving conditions on the West Coast of Canada can be quite different from most.

Also keep in mind that a TB spacer will do next to nothing for you. It can be a controversial mod, and I personally feel they're worth about 5 cents for what they claim to do. Again, from my own analysis.

[agrazela]

I have a never-installed 1/8" thick LE phenolic Gen3 M90 spacer I made as part of a now-abandoned project (I went to IC for my top-swap instead). I believe 1/8" thickness should require no modification to your fuel rail, and you'd probably get away with using the same belts and S/C-to-LIM bolts.

PCV and EGR holes are in it, but TB coolant holes are not. I painted it Rustoleum BBQ black:



I also have 2 unused stock Gen3 S/C gaskets I'll never use (I went to home-made silicone sheet gaskets). I'll also throw in 6 (or 12 as you wish) new viton fuel injector o-rings from a McMaster-Carr mega-pack.

It ain't 1" or even 1/4", but if you want to "dip your toes in the water" for $25 plus shipping, LMK.