Aspec GT35/40 Drool shots
Rotary Freak
Joined: Jan 2002
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From: l.a.
looks great, though i would like the runners to be more equal length. i'm ****, but i would like the front runner to be just a touch longer to better match the rear primary. also, i don't like the interface btwn the the merge collector and the flange. it needs to be straigth, not at an angle like that. if you try and visualize the path of the exhaust gasses and pressure pulses, you want to guide them straight into the turbine housing and have them hit the turbine wheels exactly perpendicular to extract the most power out of the exhaust energy. this angled design makes the exhaust hit the side of the tubine housing due to the inertia of the gases and pressure waves. this leads to increased reversion, pressure wave interference, lower exhaust velocity, and an overall reduction of exhaust energy.
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Joined: Apr 2002
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From: Rotaryland, New Hampshire
Originally posted by fdracer
looks great, though i would like the runners to be more equal length. i'm ****, but i would like the front runner to be just a touch longer to better match the rear primary. also, i don't like the interface btwn the the merge collector and the flange. it needs to be straigth, not at an angle like that. if you try and visualize the path of the exhaust gasses and pressure pulses, you want to guide them straight into the turbine housing and have them hit the turbine wheels exactly perpendicular to extract the most power out of the exhaust energy. this angled design makes the exhaust hit the side of the tubine housing due to the inertia of the gases and pressure waves. this leads to increased reversion, pressure wave interference, lower exhaust velocity, and an overall reduction of exhaust energy.
looks great, though i would like the runners to be more equal length. i'm ****, but i would like the front runner to be just a touch longer to better match the rear primary. also, i don't like the interface btwn the the merge collector and the flange. it needs to be straigth, not at an angle like that. if you try and visualize the path of the exhaust gasses and pressure pulses, you want to guide them straight into the turbine housing and have them hit the turbine wheels exactly perpendicular to extract the most power out of the exhaust energy. this angled design makes the exhaust hit the side of the tubine housing due to the inertia of the gases and pressure waves. this leads to increased reversion, pressure wave interference, lower exhaust velocity, and an overall reduction of exhaust energy.
also how does the wastegate tube come off the runners? is it at a 90+*? Is that ok? i only ask because soon i will be going down a similar road and dont want to make a mistake
looks aweasome to me, who make your DP? Apsec? Got me a new wallpaper
Rotary Freak
Joined: Jan 2002
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From: l.a.
wtf, you are ****** idiot if you think that. champ car, and previously turbo formula 1, all spend millions of dollars every year in r&d. all of them run equal length headers on turbo cars. they have to make a lot of sacrifices to the body, the weight, and the placement of the radiators and accesory systems striclty just to have the proper length equal length headers. the benefits of proper pressure wave tuning are even more important on turbo cars, because not only does it help evacuate the exhaust and bring in more inlet charge, it also serves to help spool the turbo. anyway you can help air move efficiently in a turbo car, results in a much larger gain than in an all motor application. look at the turbo nhra pro mod cars, that make over 2500rwhp, they all run equal length headers. i'm just pissed that you could be so stupid and yet you have a performance shop. i just ******' hate hate hate hate it when i see all these shops opening and the people there just have absolutely no clue about engine dynamics.
Where did you acquire that info from? Any possible links? Look at every turbo engine from the early 90's F1 cars (1500bhp out of 1.3L!), all are equal length long tube. Many turbines are designed to take erratic pulses and make them work but it's less than optimal. Ideally, evenly spaced pulses work much more efficiently. Check out many of the LeMans and GT type cars from Porsche, perhaps the Stillen GTP 300Z, etc...I've seen their setups up close and personal and ALL were equal length. I'm not saying that I'm 100% correct on this, only reporting what I have seen. There's a book called 1000 Horsepower (or something along those lines) that chronicles the technology used in F1 during the turbo era. Out of print so you'll have to do a bit of searching. I'm sure they have a section on turbo header tuning.
LOL I think your post came up about 10 seconds before mine :-)
But back to the GT35/40....I heard that the turbo was also going to be moved back/down, is this true? I can't stand the way my T78 sits waaaay up front. Poses all kinds of packaging and heat radiation issues.
But back to the GT35/40....I heard that the turbo was also going to be moved back/down, is this true? I can't stand the way my T78 sits waaaay up front. Poses all kinds of packaging and heat radiation issues.
Originally posted by Sl0w7
ok so how much power can you make with that turbo??? i have seen on here people say around 400WHP but on rx7store.net it says 700... WTF??? who is wrong here???
-Keith
ok so how much power can you make with that turbo??? i have seen on here people say around 400WHP but on rx7store.net it says 700... WTF??? who is wrong here???
-Keith
Jason
Jason,
It's 700 hp at the crank, on a piston engine.
Magnus put 595 hp to the ground with it on a 4G63, so technically you're not wrong with your claim. Little creative license though
That was 30 - 35 psi, I think.
It's 700 hp at the crank, on a piston engine.
Magnus put 595 hp to the ground with it on a 4G63, so technically you're not wrong with your claim. Little creative license though

That was 30 - 35 psi, I think.
I'll have to third the equal length thing. Rice Racing and many other people have posted articles excerpts from papers etc that describe why and what benefits are achieved from equal length headers on a turbo car.
Additionally, on the 35/40 I don't like the T3, non divided turbine housing... which is why I have arranged for a custom divided T4 housing to be used with my own custom 35/40/T4 turbo setup.
Additionally, on the 35/40 I don't like the T3, non divided turbine housing... which is why I have arranged for a custom divided T4 housing to be used with my own custom 35/40/T4 turbo setup.
long tube equal length headers are a must on high horsepower turbo car's.
Whoever said it was proven that long tube headers don't work on turbo cars has his foot up his ***.
Whoever said it was proven that long tube headers don't work on turbo cars has his foot up his ***.
Last edited by enzo250; Jul 5, 2003 at 11:26 AM.
Originally posted by Resource
Equal length headers are irrelevant on turbo cars. The exhaust is under pressure. It's been proven time and time again that equal length runner can only benefit non turbo cars.
Equal length headers are irrelevant on turbo cars. The exhaust is under pressure. It's been proven time and time again that equal length runner can only benefit non turbo cars.
http://www.amazon.com/exec/obidos/AS...roduct-details
Originally posted by fdracer
wtf, you are ****** idiot if you think that. champ car, and previously turbo formula 1, all spend millions of dollars every year in r&d. all of them run equal length headers on turbo cars. they have to make a lot of sacrifices to the body, the weight, and the placement of the radiators and accesory systems striclty just to have the proper length equal length headers. the benefits of proper pressure wave tuning are even more important on turbo cars, because not only does it help evacuate the exhaust and bring in more inlet charge, it also serves to help spool the turbo. anyway you can help air move efficiently in a turbo car, results in a much larger gain than in an all motor application. look at the turbo nhra pro mod cars, that make over 2500rwhp, they all run equal length headers. i'm just pissed that you could be so stupid and yet you have a performance shop. i just ******' hate hate hate hate it when i see all these shops opening and the people there just have absolutely no clue about engine dynamics.
wtf, you are ****** idiot if you think that. champ car, and previously turbo formula 1, all spend millions of dollars every year in r&d. all of them run equal length headers on turbo cars. they have to make a lot of sacrifices to the body, the weight, and the placement of the radiators and accesory systems striclty just to have the proper length equal length headers. the benefits of proper pressure wave tuning are even more important on turbo cars, because not only does it help evacuate the exhaust and bring in more inlet charge, it also serves to help spool the turbo. anyway you can help air move efficiently in a turbo car, results in a much larger gain than in an all motor application. look at the turbo nhra pro mod cars, that make over 2500rwhp, they all run equal length headers. i'm just pissed that you could be so stupid and yet you have a performance shop. i just ******' hate hate hate hate it when i see all these shops opening and the people there just have absolutely no clue about engine dynamics.
if half the shops opening have this level of knowledge (which i thought was common sense).....maybe i should open up a shop!
on a good note - the tig welds look pretty nice!
baddog - why the stock motor mounts though??
I'm surprised at how sharp the kink between the manifold and the turbo is -- there's no curving / smoothing out there whatsoever! I wonder how much power / spool that's leaving on the table...
-Manolis
-Manolis


