SVO Blower questions, JLT CAI, Meth injection, belt size, max rwhp, etc?

[Speeds8erM-1]

Just bought a 98 GT with an SVO Supercharger, SVO Heads, PI Cams, FMS Shorty Headers, Bassani Catted X Pipe, and Roush Side Exhaust setup.

It doesnt make full boost as soon as you hit it, and has a momentary lag, so Im not sure if the belt is slipping off the hit or not (although my experience with blowers has been the belt usually slips in the upper rpms, this is my first roots style though), it's hard to tell too, because it has a digital boost gauge. Could it be the bypass valve is setup to do this stock with this kit? Even with a bit of throttle, it really doesnt make boost, until you are pretty close to WOT.

What size belt does it take with the stock pulley? Also, I know people were getting pulleys for them years ago through ASP, is there a wait for that, or do they have them ready to go? Any chance of say, a Lightning pulley fitting the blower? I know the rib size isnt right, but the belt should work, if the pulley actually fits.

Anybody ever tried meth/water injection with these? I know the 03-04 Cobra and Lightning guys dont have alot of luck with methanol on them, but they have an intercooler stock, this setup does not, and it REALLY hates the heat. Would injecting before the blower be worthwhile?

It still has the stock air tube, a smallish K&N, and stock maf, I wonder if a JLT RAI, 70mm TB, and bigger filter would wake it up? If I did a 90mm LMaf or SCT, I would need to get it retuned. Im debating on what to do.

Whats the max rwhp out of this setup with a pulley, bigger cai, tb, maf, meth, ported by Steggy, etc? 400-425 possible?

 

[squeak93]

Tons of questions here. I'll answer the ones I can help with...


First of all, stock maf and t/b (esp t/b) choke a stock car.... So its easy to say that one with a blower will suffer even more. So up grade to a blower friendly maf, 75mm t/b and good intake tube to help with boost.

I've heard of lots of folks that have had great luck with meth injection. But another option if you don't want to risk it is a small shot of n2o. (50 or so) to help cool the intake charge before the blower.

That being said, what size of a pulley does it have on there right now? What type of tension set up is on it?

 

[Speeds8erM-1]

I know doing the basics will help, just wonder how much of an effect they would have. Getting rid of restrictions before a roots style blower usually makes a pretty big difference, but this one isnt getting making alot of boost. I dont wanna bother with a 75mm tb, the inlet on the blower setup is only 70mm.

I know plenty of people with meth on blower cars, but the only person I know that has tried meth on a roots or screw blower, wasnt impressed. None of the 03-04 Cobra or Lightning guys are big on it. Im not sure if it's the intercooler under the blower thats messing with them, or if the blower is too much of a big heat sink to do anything with. Injecting after the blower would probably work, but I havent looked to see if there is even a decent spot for that on this setup.

I thought about doing the bottle too, since I have two kits, but then I will end up with a slow car that has a blower AND nitrous on it LOL. Then again, a small shot could actually pickup QUITE a bit of power on this, the thing is, I want something to cool it everytime it's WOT.

It has a 3.4 or 3.5 pulley on it now, the blower kit adds an idler pulley to the mix. I have heard of guys getting 9-10 psi out of these kits with pulleys from ASP, but never saw any big dyno numbers, it seems like most of the guys that did the pulley, had stock heads.

Im gonna dyno it this week and see what it makes, as it sits, here in Fl, in the heat on the dyno Im used to dealing with. Previous owner had the car tuned 7+ years ago and couldnt remember exactly how much it made, 330, or 345 rwhp.

 

[the98stang]

I want something to cool it everytime it's WOT.

FMIC from ebay

 

[Speeds8erM-1]

I cant run an FMIC with this setup.............................it's a roots style

 

[the98stang]

I cant run an FMIC with this setup.............................it's a roots style

o.....gonna have to spray nawz to cool it lol....or meth kit

 

[squeak93]

Forgive me for being blower dumb, but why can't you run a fmic on a roots? Obviously there is some difference between you set up and stock 03-04 cobras to not allow it....

 

[trinity_gt]

Forgive me for being blower dumb, but why can't you run a fmic on a roots? Obviously there is some difference between you set up and stock 03-04 cobras to not allow it....

Roots and twin screws put the supercharger in the 'V' between the cylinder banks. They inhale from the rear (typically) and discharge out the bottom. The problem is that there is little space to collect the air coming out, run it to the front of the car, through a heat exchanger then back to a manifold to feed the cylinders. A centri makes this easy by putting the discharge in an easy-to-plumb position and retaining the factory manifold.

The roots/twin screw setups then go one of three routes:

1) They choose to have no aftercooling and the blower discharge feeds a plenum directly that has runners leading to each cylinder. The SVO blower and "non-intercooled" Kenne Bell kits (for example) use this setup.

2) They use an aftercooler directly under the blower outlet, between the blower discharge and the plenum. Because there's no airflow there, the aftercooler is configured as an air-to-liquid setup, with a separate pump and coolant running through the aftercooler and up to a secondary heat exchanger up under the bumper. The heat exchanger looks just like an FMIC but it's a liquid to air unit, taking heat picked up in the supercharger coolant via the aftercooler and dumping it into the airstream. This is the setup the 03-04 Cobras, Lightning and "intercooled" KB kits use.

3) Choose option (1) above but use chemical intercooling, like water/meth. If you've ever put rubbing alcohol on your arm and blown on it you know that the evaporation of alcohol or even water requires heat. In a w/m setup, w/m is injected into the compressor outlet and, as it vaporizes, draws heat out of and thus cools the compressed air. It's an alternate form of aftercooling that doesn't technically rely on heat exchangers.

 

[Speeds8erM-1]

That pretty much sums it up lol

 

[Bullitt5339]

That SVO supercharger really wasn't designed for massive power gains, just to give a little more kick. It's good for the price, and what it was made for, but you'll never get huge gains from it, it's just too small.

I disagree that you can't front mount intercool a roots blower. You can't FMIC the SVO, but look at the TBird SuperCoupe, it's got an M90 and a seperate, front mounted intercooler.

 

[Speeds8erM-1]

It has an M112, same thing as an 03 Cobra, which is capable of mid 500's, but they are intercooled, 4v, etc.......still that nullifies the fact that it's "too small".

You cant front mount intercooler this setup, supercoupes are irrelevant to this situation

 

[tewfast]

any idea where i can get alternator bracket for this type kit? i have a allens supercharge and i beleive they use the saem type bracket that turns the alternator around? please help...lol

 

[Speeds8erM-1]

No idea, I bought the car with the kit. You may want to look around on TCCOA, alot more people have these blower kits on there.

 

[Speeds8erM-1]

Im having a weird issue. Car usually makes 5-6 psi, well sometimes it will creep up top 7-8 even 9 psi. It seems to only do this after driving around for awhile, and when shifting really hard. The car almost kind of surges slightly on the shift, then the boost gauge starts creeping up. If I just roll into it in third and start going, it doesnt get that high. It's an electric digital Nordskog gauge.

I wonder if it's something with the bypass valve?


You can see where the boost gauge is plumbed on top of the intake near the EGR.