Game ova

Tall gears are a definite plus for turbo vehicle. Personally, I started out with 295 40 17 et street and 3:23 gear. Went to a 315 35 17 and 3:42......car doesn't pull near as hard.

gsteele

At what speed does that start? I assume you are traction limited in first. I also forget, are you stick or auto?

Game ova

Yes, traction is severely limited in 1st and 2nd....often times 4th as well from a roll on. But in comparison between the two different setups.....the et street 3:23 combo was scary in comparison to now. Thinking about switching to done 2:73 to offset these short tires to very that feeling back. This is on the street btw

wildcamaro

iTrader: (15)

Just an update I put in 7# gate spring and I was seeing 4.5-5 pounds at engine (think I have a small leak somewhere, possibly boost gauge) and was getting some boost in second finally...glad I didn't up the boost too much because even though I changed target AFR in boost from factory preset 11.9 down to 11.4 I am still getting like 12.2 AFR in full boost so I need to figure out why, thinking it might be because I only have a 30" down pipe and my Wideband is splitting the difference between between turbo and exit

forcd ind

iTrader: (7)

A couple thoughts, just my opinion, from my old blow thru days, that carb hat may not be the best, but prob hood clearance is a factor, and not sure how it affects FI vs boosters on a carb.
Kind of my own opinion with a turbo vs a supercharger, the faster you run thru the RPM's, prob doesn't give the turbo time to spool up, where the latter gears the RPMs are slower, giving time for the turbo to spool-somewhere you hit that happy medium of spooling in the lower gears and the higher gears, lol-of course a lot comes into play, engine specs, etc.
I think that's where those programmable controllers can shine, boost in lower gears and the ability to control boost at the top of the run.
I am still fairly new to turbos after a bunch of Prochargers, so this is just some of my observations, and to much coffee this morn., lol

dburt86

iTrader: (2)

the short down pipe will only throw off the reading at idle. Once the thing starts making jam, it will read right.

JoeNova

Where is your wastegate getting its boost signal from? If it's from the compressor housing, the gate will always open earlier than the spring pressure.

Ratical

iTrader: (82)

Just something to check, I had an issue with low boost on my car. On the supposed 7-8 pound spring I was only seeing about 3.5 pounds. Went to the 11-12 pound spring and only saw 6 pounds. I found out I had hooked my vacuum/pressure line from my intake to the wrong port on the blow off valve. I have a JGS 50mm and I had the line hooked to the lower port by mistake. Switched them around and instantly saw 12.2 pounds.

I agree that once you find the boost issue a gear change would help a TON with that ridiculous 1st gear ratio and 3.73's. At least swapping to something like a 3.08 would make it useful and I think more fun to drive all around.

Ratical

iTrader: (82)

Did you add an external boost referenced regulator? I was reading a thread somewhere, (I think on YB) about Fitech with blow thru and it said the internal regulator will not work with boost, I believe it said you need to bypass it and use an external boost referenced regulator.

wildcamaro

iTrader: (15)

I totally agree that the low profile Spectre hat is not optimal by any means, but you are right that its a hood clearance thing, i hate having to make sacrifices but it is what it is

wildcamaro

iTrader: (15)

I am refrencing the gate from the compressor housing, you saying i should reference gate from my vacuum manifold that is feeding BOV and boost gauge?

wildcamaro

iTrader: (15)

There are two different flavors of Fitech, one is the standard unit which only has a 1 bar internal map sensor and the power adder models like the one i have that has a 2.5 bar map sensor in order to account for boost in order to fuel in conjunction with wideband...

wildcamaro

iTrader: (15)

Messed with car tonight and found I had an open vacuum port in throttle body, very dumb move on my part lol...however a 9# spring netted me 6.2# at the throttle body probably a mix of possible small vacuum leak in brake booster, cheap intercooler, the low profile carb hat causing turbulence because I'm getting a slight stumble when matting it from 2700rpm cruise in 4th...guess I just need more spring

kingtal0n

iTrader: (1)

You need to do a pressure test. Fill the plumbing with air pressure from the compressor inlet all the way to the engine. Find all leaks. This needs to be done on every turbo car, every time. Very very important.

ddnspider

iTrader: (26)

absolutely. If you reference the waste gate at the turbo then you'll never see the correct boost pressure at the manifold.

wildcamaro

iTrader: (15)

I was under the impression that you shouldn't allow the wastgate to see vacuum, only positive pressure...

Ratical

iTrader: (82)

Good to know. They must have come out with the second model after I read the thread about it.

Ratical

iTrader: (82)

My wastegates are referenced off the turbo outlet per Holley instructions to the lower port on the gate. The upper port on the gate, (dome) is fed by my CO2. I have JGS. Not sure if other gates are the same.

wildcamaro

iTrader: (15)

What's the reason for the CO2? Some sort of component for a boost controller?

3pedals

iTrader: (3)

you will not see full boost in the lower gears on a turbo stick car, unless there is enough traction to hold WOT. If tires are spinning(no load) then the boost wont be there.