boost #s

**MoDo** · 01-02-2003, 01:55 PM

what kind of boost #'s are you guys seeing and what is your setup

i have a stock shortblock, afr 165s, afm b-31 cam, afm powerpipe, and i only see 6-8 lbs of boost at the manifold... s-trim w/ 3.33" and 6.87" pullies

**Forcedpower** · 01-02-2003, 02:11 PM

I have a R331, AFR 205's and a Victor 5.0 intake. With a S trim with 6.87 crank/2.95 blower pulleys and at 6000 I see a whole 6psi.

**Goliath 5.0** · 01-02-2003, 03:37 PM

Not too sure yet as far as boost numbers and approximation, but what do you guys figure with:

An S-TRIM with 2.95 blower pulley and standard 6" crank pulley with...

Fully ported cobra intakes, fully ported gt-40 heads, stock cobra cam, 70MM Throttle Body, 80MM Mass Air, 36lb injectors, T-REX fuel pump, 255lph intank fuel pump, NO FMU... what do you guys think it will produce in terms of boost? Also RWHP/TQ numbers?

What do you guys think? :)

**MoDo** · 01-02-2003, 03:43 PM

well my setup makes 412 rwhp / 424 rwtp with 11:0 air/fuel and base timing @ 10, max advance 22

you will get close to 10 lbs of boost and probably around 400-450 depending on who tunes it

**Mitch Peoples** · 01-02-2003, 03:59 PM

Boost numbers are a factor of airflow efficiency. I got a whopping 18psi reading out of my S-trim with a stock 302, SVO Y heads, Cobra intake, Lunati "E303" spec cam and 7" crank - 2.95" blower pulley at 6400 rpm. The air wasn't moving with the intake side bottlenecks and it was reflected in the boost reading.

Now, we have a brand new CHP 342, new unported TFS TW heads, Lunati cam with SVO-X type specs and an Anderson Ford Typhoon RPM intake that's been cleaned up. Best reading so far is 10psi at 6000 rpm. I don't think it'll go up much more with an extra 400 rpm. We are now going to look for a used T-J trim or whatever will fit in the standard S-trim brackets.

Mitch

**stangjr** · 01-03-2003, 11:21 PM

Yeah I agree with mitch on the boost #. I had a gt-40 upper and lower intake, I saw 12# of boost. when I put a cartech upper intake it dropped to about 9.5#. that was my restrictive area. The pully was a march 10#.

**BEEFEDMOD** · 01-05-2003, 12:49 AM

I have 98 Cobra with forged .020 over motor, built by Lidio at Alternative Auto in Michigan.

Diamond pistons 9.8-1, Eagle rods, Total Seal rings, stock crank, stock cams, P & P'd heads, shortened ported intake, Accufab TB, V2 Vortech with S-trim upgrade, 6 rib, UPR power pipe, 42 lb injectors, MSD DIS-4, Autologic,BBK long tubes, Dr Gas O/R X with 1 chamber Flos. Big Bosch fuel system with 110 Turbo Blue Running 15.5 PSI on Dyno, 548 RWHP @ 7400. Best ET 11.09 @ 126.1 with 1.60 60' ft. New spool gives me 1.52 60' so 10.90's could be had if winter had not of set in so fast!

Back to Lidios shop now for T-trim, 8- rib, SFI dampiner, reflash Autologic, and 17-18 PSI safe tune.

New to this board...I already see a lot of knowledge available!!

**Trey** · 01-06-2003, 02:47 PM

I have:

-Stock heads and bottom end.
-GT40 lower intake and explorer upper both mildly ported, polished and gasket matched.
-65mm TB
-75mm ProM MAF
Anderson Power Pipe
MAC unequal lengths

S-Trim
2.95 blower
7 crank

Most boost I've see is 12#. The temp was about 55* and the altitude was 4800.

**Big Daddy** · 01-07-2003, 08:06 AM

I have a S-trim & aftercooler with the 3.125 pulley Forged internals stock cams Kooks headers with h-pipe, high flow cats, Bassani Catbacks, & stock heads. With the stock pulley that came with the system I never made over 8 lbs of boost but I thought I should have been making 10 from what I read in Vortech's literature. Now it's making 10 lbs with the smaller pulley?? Is this correct?? He's still tuning it but as of yesterday it made 500 rwhp and 425 torque on a '01 Cobra 4.6 L DOHC.

**Mitch Peoples** · 01-07-2003, 09:03 AM

A smaller blower pulley ( or larger crank pulley ) will increase the speed the blower turns at. Vortech has a calculator on their site that will give you impeller rpms based on your engine rpm and pulley sizes. It will help you figure out if you are exceeding the max impeller rpm for the head unit.

How do you like the aftercooler? Does it make any difference on the street where you are running regular coolant as opposed to icing it down at the track?

Thanks,

Mitch