engine mods advice
 

hey folks... have just had cosworth headgaskets put on my scoob... when the mechanic tightened up the rocker cover bolts hes rounded off 2 threads so gotta have the engine out again to hellacoil it.. nowim thinking i mightaswell stick someother bits on while its out to make it worthwhile. ive got a v2 555 sti and its cdb. has anyone got any ideas how i could make some decent power/strength upgrades and for what prices as im not that clued up on the engine. cheers

well as the heads have been tourqed down now your abit late to do any internal stuff as pulling them off would mean throwing away cosi head gaskets but as its out you could change the turbo or manifold for stainless tubalur type which with aremap would c some decent power increase.

i was thinking turbo as ive got a td05h and i know some companies will do discounts on the 20g's if you give your old 05 in as exchange. what sort of stainless manifolds would you recommend? i don't have a clue about them haha

all depends what your budget is fella?and turbo wise id go for a ihi unit not the 20g.

i havent set myself a budget really... ill just save up.. just want something midrang i guess... a decent upgrade for not silly money..

why do you say ihi ovr the 20g's anyway? is that just your opinion cos ive herd nothing but good bout the 20g's.. if i cud get to 400bhp id be happy for now

its just that the ihi are in my opinun astronger unit and more reliable and you need to upgrade more with 20g cause they do produce alot more volume/boost than ihi as long as you buy the proper 20g not the cheap jap poopy 1 lol.

well i had a vf23 ihi on my v3 and they are good turbos... what ihi wud be good for 400bhp then do u think? and if its cheaper than the 20g then i might just go for it.

vf 34/35 are good units and good for what your after about 1.5 bar with the right fueling and ecu to keep it all in tune,and if you go tubalur mani with decat that would make road rocket:D

http://cgi.ebay.co.uk/SUBARU-IMPREZA...item2558a99fdc

is this what you mean with the manifold? whats the difference between the 34/35 aswell?

that manifold is good for tourqe but the dpwn sides are that u need to modifie the lower front panel and you loose the scooby rumble,34 is single scroll and 35 is twin scroll more expensive though,id go with 34 and unequal length as the tourqe gain is only marginal and the rumble is part of the scooby appeal:thumb:

sounds good man.. thanks alot :thumb:

if any1 else have any other opinions id be happy to hear them..

You've got your terminology wrong - the 34 is roller bearing; the 35 a regular thrust, or sleeve, bearing. But effectively similar performing, with the 34 having a tad more top end; the 34 being a tad more lively.

Both have conventional single scroll exhaust feeds.

Also, it's accepted that the TD series of turbos, are mechanically more robust than the IHI units, given a like-for-like age.

i was hoping some body might pitch in,is it the 28 thats twin then fella

sorry for hijackin ur thread mate but i have got a v5 sti - its got a ihi vf28 as standard , harveys gt front mount, k & n, a full decat and a simtek ecu and i am pumping out 336 bhp, would a vf35 make a big difference?

also these big turbos whts the spool time like compared to my vf28 and why does it get rid of the burble!

the reason they rumble is cause the manifold is unequal which means the gases exit the exhaust at different times hence the rumble and yes the 34 is slightly laggier [marginal] but worth changing cause ud defo c more power fella.

no you're not :hjtwofing lol... i think the 35's are good for about 400 mate

but woul it just make that if i put a vf35 on ? an extra 70 break bhp with a remap? that cant be true ! if so i am getting one!lol

Not even close to 400. On average the VF35 will make 340bhp. One or two examples have made up to 370 but no way 400.

I'd stick with the TD05 16G and max it out with ESL board and live remap. Will save the hassle of getting a top entry housing for a VF for very limited power increases.

* VF28 std fitment on STi 5/6's, so no - it's conventional single scroll (I have one on my own STi 5).

Re. OEM-fit turbos, it's only the much later newer New Age STi-fitment VF range that have twin scroll options - if memory serves (which it wont! lol): VF37 (or is it 39?) and VF43 (or is it 48 or 49?). I told you my memory wouldn't serve! ;)


* Also, as dynamix says, VF34 in the c.340-370bhp area; VF35 in the c.330-360 area... But defo NOT 400!

VF43 and VF48 are both single scroll.

Cheers - couldn't recall properly. ;)

So 37, 39 and 49 are the T.S.? Any other OEM VF's that are T.S.?

36, 37 and 42 Joz :)

Tony:)

Everything below the VF36, ie the 35, 34, 30, 29, 28, 24, 23 etc are all single scroll units, the vf36 was the frist twin scroll unit and it wont fit on a single scroll car without alot of work.

OP, 400bhp is possible on your engine, it wont last long (could be 1 mile or 100) then you will be looking ofr a new block as well as the old one will have a nice hole in the side of it where the piston ejected itself out the side, if you want 400bhp then its a fair bit of cash, especially ifyour after reliability throughout the car, your talking full engine rebuild with all the parts, circa 3500 quid, fmic, brakes, clutch, gearbox (that wont last long) so 6 speed is a worthwhile investment, those are 2.5k with the rear diff, or a ppg box (not as strong but 5 speed) for 5k new, 2.5k 2nd hand, possibly replacing the tired suspension, add another 1k, some ancillaries, add labour, so your looking at around the 10k mark.

Your other option is keep the TD05 (which is a good turbo, capable of 350bhp) which is about as far as you want to take it on the standard internals if you want reliability, personally 330bhp would suffice most of the time, but if you want the 400 go for it, if you dont pay the costs of the above though, your car will be either in the scrap yard or off the road for a long time :(

Tony:)

:thumb: for the T.S. enlightening.