HARROP TVS, What You Need To Know & FAQ
the bypass valve can be used to limit boost, the stock car is limited at like 12, if you get higher than that the bypass valve cracks open and bleeds some of the boost, preventing you from building more pressure, im just curious if anyone has done this to keep the tvs on pump gas. i dont want to wind her up to 7k to get power, id rather run the smallest possible pulley to get instant torque and hp, set the red line at 7k and limit her boost to 20psi. seems like it should be simple, seeing if its been done.
Its possible but it would take a lot of tinkering to get the exact PSI you like. The limit boost feature is not determined by setting a desired PSI. So it will take some playing around with to get the tune right.
Stock Injectors Stock Pulley Stock Tune and all the bolt-ons - Saturn ION RedLine Forums
the bypass valve can be used to limit boost, the stock car is limited at like 12, if you get higher than that the bypass valve cracks open and bleeds some of the boost, preventing you from building more pressure, im just curious if anyone has done this to keep the tvs on pump gas. i dont want to wind her up to 7k to get power, id rather run the smallest possible pulley to get instant torque and hp, set the red line at 7k and limit her boost to 20psi. seems like it should be simple, seeing if its been done.
the torque curve and hp at rpm of the tiny pulley are great, but the big boost is too much for most motors, my car is my daily driver so i want power that doesnt blow my motor apart and butt dyno is the most important thing to me
im a few tiny mods from maxing out the m62 on pump gas then its time to talk tvs and porting. if no one has done this yet, ill get with my tuner and see what we can do about it once the tvs shows up. of course at some point a small cvt in place of a snout is going to have to be a reality. its literally embarassing that it isnt already a standard feature on all superchargers.
im a few tiny mods from maxing out the m62 on pump gas then its time to talk tvs and porting. if no one has done this yet, ill get with my tuner and see what we can do about it once the tvs shows up. of course at some point a small cvt in place of a snout is going to have to be a reality. its literally embarassing that it isnt already a standard feature on all superchargers.
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From: West Carrollton (Dayton), OH
If you have proper mods (I.E. ported head, full exhaust, and a custom tune) then you're motor will be fine. Opening up the motor and exhaust reduce pressure buildup by increasing efficiency. My TVS w/ a 2.7 pulley only hit 20psi
thats high mine with my 2.7 pre meth on an average day 70s would see 17.8- 18 peak boost. after meth and on a cooler night maybe 19. (stock head)
Joined: 12-30-07
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From: NEPA
It's very hard to compare boost readings between 2 cars even if they are running close to the same setup. Lots of factors to take into consideration.
Joined: 12-30-07
Posts: 14,079
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From: NEPA
I've never played with it, but isn't it this: LSJ Boost Bypass - HP Tuners Bulletin Board ?
Originally Posted by omega_5
It's on the top right side of the screen, under "Boost Control". There are two tables.... Desired Torque (or MAP) and Desired Torque (or MAP) S/S.
The tables will have an RPM axis going across the top, and gears 1-6 on the side. Earlier PCM's will have boost in this table (the ones labeled 'MAP')... but newer PCM's will have a torque number is ft-lb (the ones labeled 'torque').
The tables will have an RPM axis going across the top, and gears 1-6 on the side. Earlier PCM's will have boost in this table (the ones labeled 'MAP')... but newer PCM's will have a torque number is ft-lb (the ones labeled 'torque').
this was like 3 years ago so i cant really remember, but i thought i just changed like 1-2 tables in the tq management...hell, tbh im no totally sure that i actually got it to sit at 4psi(on the stock gauge)...but im guessing that i just changed boost limit vs gear, all i really remember is that i was thoroughly disappointed with the power lol i couldn't hardly merge onto the highway or even pass anyone one haha
something else to keep in mind. the tvs does not hit like the m62 on terms of instant torque. think of it like a big turbo. my guess is due to the rotating mass, and air volume moving in there. if you spin it high enough {above 7k} you can see some good power numbers. the power doesn't drop off like the m62 does either.



