General Centrifugal Supercharger Discussion

[White_96Cobra]

Haha, I know what you guys mean with the sound complaints. I had a T-trim and Tial Q BOV on my Cobra and everyone at work was like 'why does your car sound like a 747 when you drive in?' Could definitely street sweep a road with the BOV too, I think the air coming out of that thing at idle was more than the aux fan pushed when it was on low.



There is a big difference in the amount of air being released by a BOV between an Evo and a blown V8. Just think, an Evo has a relatively small turbo forcing air through maybe 2.5" piping, relatively small I/C and into 2.0L of engine. A blown Cobra has a huge supercharger forcing air into 2.5-3" piping, through a big intercooler, and into 4.6L or even 5.0L of V8. I'd want a much bigger BOV on the V8.

I had the Vortech Mondo on my car and it didn't seem to be working right, so I bought the Tial Q 50mm BOV instead. Same BOV the pros use, including a pair of them on just about any TT Viper, Ford GT and Gallardo you'll see. The thing is LOUD too, which I usually didn't mind. Cruising down the road at highway speed wasn't bad, but drop it in 3rd at 65 mph and you'll destroy the ears of the person in the car next to you. Ask my friends :-D

Anyway, 20+psi has my old Cobra, ask him about it. I'd bet it'll work just fine even with his new YSi setup.

Yeah, I do realize that the EVO will flow alot less. I was just saying that I remember my buddy sayin somehing about doing that mod to the BOV.

Also, at least for now and into the near future I will be staying below 10psi. Right now I'm at 6 and the BOV seams to be doing fine. It does whistle just cruising around tho, and that is annoying but usually just using the next gear quiets it down a bit. Once I go more I will probably switch to the Vortech Race BOV or something bigger.

 

[White_96Cobra]

B-Head cobra guys, has anyone ran without doing the IMRC delete once boosted?

 

[98 Saleen Cobra]

I ran for a while without an IMRC delete when I had B-heads.. I remember my tuner saying something about them fluttering when they opened under higher boost. I was at 10-12psi iirc. So since they were fluttering I felt better doing an IMRC delete on it.

 

[SilverSteed]

Yeah, I do realize that the EVO will flow alot less. I was just saying that I remember my buddy sayin somehing about doing that mod to the BOV.

Also, at least for now and into the near future I will be staying below 10psi. Right now I'm at 6 and the BOV seams to be doing fine. It does whistle just cruising around tho, and that is annoying but usually just using the next gear quiets it down a bit. Once I go more I will probably switch to the Vortech Race BOV or something bigger.

Correct me if I'm wrong but does it not take an equal amount of air and fuel (give or take a bit with regards to a/f ratios) to make a given amount of horsepower? So whether it be a 2 liter evo making 400 or a Vortech'd GT making the same shouldn't the cfm be the same despite differences in psi?
Therefore if the greddy works on one it should be fine for the other. Hope I'm right-this is my setup for the coming season.

 

[20+psi]

I love the way the car sounds with the Tial BOV. I always have someone asking why it sounds that way, or thinking something is wrong. However with the YSI it is moving so much more air it is even louder now. When I shift the car at high RPM's it sounds almost as the Tial can't keep up and I hear a bit of surge.

I might have to add one more Tial to make sure there is no surge on the compressor. I got my 30# boost gauge in today and will install it tomorrow and find out how much boost the car is making. With the cooler air the car is running so good, man it's an insane ride!

 

[White_96Cobra]

see below, accidentally double posted.

 

[White_96Cobra]

I ran for a while without an IMRC delete when I had B-heads.. I remember my tuner saying something about them fluttering when they opened under higher boost. I was at 10-12psi iirc. So since they were fluttering I felt better doing an IMRC delete on it.

I notice that sometimes the car will jerk a little with them in, I think it is something to do with the fuel not coming in fast enough when they open up.

20+ What symptoms do you see when you feel surge?

 

[98 Saleen Cobra]

Hey just an FYI for everyone. I'm scratching the 2.75'' pulley and sticking with my 3'', as I'm worried that it'll be to much for 93oct.. I'm thinking that the pulley will give me around 19psi which is to much and the timing will only be at lik 15degrees which is to low and puts alot of stress on the valve guides. So the new plan is this.. the 3'' pulley which is around 15psi at 7k. SO I'm going to run more timing on a lower psi which will be better for my valve guides and safer for 93 oct, plus the 98 cobra cams.. So just an FYI before I was making 605rwhp on 15psi and 21 degrees of timing and 100oct with 04 cobra cams.. So think that rwhp plus whatever the 98 cobra cams will add on 93 oct and 15psi..

 

[AntiHeightPunk]

meth + 25psi = do it now

 

[98 Saleen Cobra]

25psi out of a T-trim?? you're crazy lol... Atleast I'll have some real world answers for the biggest question for the Termi guys. and that is how much rwhp does 98 cobra cams add with everything else staying the same lol.

 

[AntiHeightPunk]

oh i thought you had a bigger blower my bad lol

 

[98 Saleen Cobra]

shit I wish! If I had a YSI and a FMIC I would be spinning it high as hell.

 

[Myzticsnake]

shit I wish! If I had a YSI and a FMIC I would be spinning it high as hell.

You'd need to spin monster rpms to get the full advantage of the ysi, 7500-8000 at least. I think the t-trim is better for the street honestly.

 

[sunburned]

I love the way the car sounds with the Tial BOV. I always have someone asking why it sounds that way, or thinking something is wrong. However with the YSI it is moving so much more air it is even louder now. When I shift the car at high RPM's it sounds almost as the Tial can't keep up and I hear a bit of surge.

I might have to add one more Tial to make sure there is no surge on the compressor. I got my 30# boost gauge in today and will install it tomorrow and find out how much boost the car is making. With the cooler air the car is running so good, man it's an insane ride!

I guess if you need a 30psi boost gauge, another BOV wouldn't hurt for a little blower longetivity lol. The Tial is surprisingly inexpensive for how awesome it is. Make sure you tell them you are running a supercharger though. When I originally ordered mine, I got the spring based on the amount of vacuum the car pulled, but it wasn't correct. They have a special lightweight spring designed specifically for centri superchargers.

 

[1Sick2Valve]

So who all is using that 928 motorsports BLV? And what size blower are you using it on?

 

[BADD281]

Yeah the Tial BOV's on a blower setup is really loud. I had the Tial Q when I first set up my car but soon after realized I just couldn't handle how loud it was everywhere I go. Switched over to the Tial alpha Q which is their new recirculating one. Looks like a bong but damn this thing is near silent when you are just cruising around. Sounds amazing when you let out boost at high rm though. I didn't recirculate it and it is still silent just releasing from the valve.

 

[20+psi]

I guess if you need a 30psi boost gauge, another BOV wouldn't hurt for a little blower longetivity lol. The Tial is surprisingly inexpensive for how awesome it is. Make sure you tell them you are running a supercharger though. When I originally ordered mine, I got the spring based on the amount of vacuum the car pulled, but it wasn't correct. They have a special lightweight spring designed specifically for centri superchargers.

Dale did you change the spring out to the correct one?

 

[RSbeast]

So, do these cars grow some nuts with a blower or do they still feel doggish around town? I've had a centri 5 liter car but it was always quite torquey. Felt big blockish with the blower, very grunty for a 302; screamed up top.

However it was a lighter car. I have a full weight vert with added and subtracted weight from the full MM setup. EVERYTHING on this car is tubular. It weighs 3860 with me in it and a hair under half a tank. 3620 w/o me. This weight + windy 4v = the not most fun experience around town. The car has an WMS velocity tube, o/r H pipe, super 44 catback, and 3:73s aside from a spec stg2 and a MSW handle on a pro 5.0 base.

It's gone the 13.5's in my sig on near bald DRs with a 1.87 60'. That was in SUPER good air though. So it's not THE worst when it's twisted out but eh.

Anyhow; I have a vortech t-trim with a AFM powerpipe and all polished charge piping (non intercooled). I'd really like to get some input on how this thing is going to run. I don't have the $ to forge the car right now; and truthfully not to even finish what I have for awhile with the job situation. Will it get out of it's own way without revving the piss out of it? I looked at a few dyno graphs but I can't seem to find any stock ones to compare it to. It seems like it's going to love the rpm under boost however.

The car is basically a street toy that doesn't get open tracked as it should (cost prohibitive) and it makes a few trips down the 1320 a year. I guess 11's would be a 'goal' but mid 12s with boost will be fine before I forge it.

What I'm asking is will I be disappointed with the weight and the way this car makes power? Should I maybe move on before I get in too deep? I was trying to replace my old 5.0 with an LS1 platform in either vette or ws6 form but I got fed up with crappy cars for alot of $ and I got mine for a fair price in near showroom condition underneath with an almost equal exterior/interior after a nice cut and buff. The car is gorgeous. My brother has an 2000 SS m6 car, his 2nd LS platform; I've owned an m6 lt1 so I've driven my fair share of LS cars to know how they feel nice and torquey around town.

What's everyone's suggestions/predictions? I'm terminator weight looking at non terminator tq with the centri Still fun?

Thanks!

 

[AntiHeightPunk]

so my auto was pretty much the best mod everrrr

 

[sunburned]

Dale did you change the spring out to the correct one?

Yup, I emailed Tial right after I installed it saying it wasn't really working right and they hooked me up with the correct spring right away.

Just wanted to let you know so if you order another one, you can get the correct spring from the vendor.