Wastegate options?

[scooby_si]

Just a question at this time to try & educate my fragile little mind http://www.smileycentral.com/?partner=ZSzeb008\' target=\'_blank\'>http://smileys.smileycentral.com/cat/12/12_6_13.gif\' border=0> so what are the different wastegates & their pros/cons i believe a bigger one is cunning if yer going pretty big BHP but what\'s the full SP with external & wotever other differences are possible etc etc?
Cheers
Si

[20B_boy]

Retaining stock twin turbos? then forget about changing wastegates Its a non starter.

[scooby_si]

but if for example it needed to be changed say then surely it would be cunning not to replace it with a small original one which may prove to be insufficient at a later date so was just looking at options & what is the crack with getting a fat load of wastegate chatter kinda thing?
Si

[20B_boy]

Simon, Simon ;-)

Its a bit tricky to see how it looks on the car looking at the pic, but the stock wastegate flapper is part of the exhaust manifold - you cant replace it with a bigger wastegate - well not without out having a custom manifold and control system made up.

All you can do is port the wastegate aperture as much as you can - which isnt a great deal.

That help?

[scooby_si]

so what is an extermnal wastegate then?
Si (aka mongol extraordinair )

[20B_boy]

One thats not part of (built in to) either the exhaust manifold or the exhaust housing of the turbo itself...

[Glenn Butcher]

Si - here are some examples:


And a kit:

[scooby_si]

Glenn stop trying to seduce me with shiny bits lol but they do look nice, which only leaves the most important question of pros/cons of any such goodies?
Si

[Glenn Butcher]

Much of it depends on how deep your pockets are

The twin turbos are limited in the power they can produce.  A single turbo is more efficient (well two single turbos for a 13B is probably even better).

Boost spikes/creep is very difficult to control on the standard twin turbo set-up - this is just one of the reasons as to why people prefer singles.

Like all these things though, you need a good base to work with (engine), good turbo/manifold/wastegate set-up, ECU, IC, etc. etc. and someone that knows what they are doing with it all.


A really good single turbo conversion will cost quite a bit of dosh really when added all up.  And of course you want something that is almost factory from the tune right down to the fabrication work in the manifold/exhaust system etc. --> for reliability.

[skybusr34]

does anyone know of an rx7 running twin turbo`s on an rx7.  no not talking about non-sequential.  two turbo`s running in parallel    ( one rotor each)   wouldn`t this give huge increase of power. without single turbo lag.    im quite a newby  so not huge amounts of knowledge

[Jus]

I don\'t know if anybody has mentioned, you can port the wastgate but you can\'t take to much off.

I\'ve heard there is an improvement but to what degree? Maybe someone has completed this here?

Jus

[igy]

Originally posted by harris2182
does anyone know of an rx7 running twin turbo`s on an rx7.  no not talking about non-sequential.  two turbo`s running in parallel    ( one rotor each)   wouldn`t this give huge increase of power. without single turbo lag.    im quite a newby  so not huge amounts of knowledge

I have run a twin TO4S setup on my car personally, and in most cases I have seen running 2 turbos that will make as much power as a big single the twins usually have slightly more lag.  Take the stockers in non-sequential, they max out at 400rwhp and spool at 3500rpm\'s as compared to a TO4E that with correct exhaust side sizing can spool at 3200 and max out at 400rwhp.

[antnicuk]

I am a little confused about this,  are you saying you can get 400 hp out the stock turbos, and you can get 400 from a to4e, the only difference is the TO4E will spool earlier?
I didnt know you could get that much hp from the stock turbos.  I am running a TO4E, I am still running it in but from initial blats there is virtually no lag. The turbo spools up instantly.  What it will do at top end will be seen soon.

What A/R doo you recomend?

[clive]

Originally posted by igy
I have run a twin TO4S setup on my car personally, and in most cases I have seen running 2 turbos that will make as much power as a big single the twins usually have slightly more lag.  Take the stockers in non-sequential, they max out at 400rwhp and spool at 3500rpm\'s as compared to a TO4E that with correct exhaust side sizing can spool at 3200 and max out at 400rwhp.

Hi igy and Welcome to MRC,

Do you have any pictures of your monster Turbo set up you could post.

[igy]

Here is a pic of both of my setups.  

Yes, with a ported motor and some boost you can make 400rwhp on stockers.  The turbos aren\'t going to last long, but they will do it.  I suggest an AR .84 p trim with stock port FD.