NA-T Conversion Q's

I am making plans for getting a soop soon need some direction at the moment:search:

Basically i want a tt but as i only have expriance in FF cars im too woried of stacking it

so i thaught ill go for a tt first then a tt after.

but just thinking what is involved in a NA-T conversion and how much?

Would it be more worthwhile/cheaper to go for a tt first???

Any opinions/ advice is very welcome

ill go for a tt first then a tt after?

nevermind, i think i know what you meant lol.

in short, yes you'll be better off getting a TT in the first instance mate.

NA-T is do-able but if your really want a TT, buy one in the first place.

yeah thaught so!!!!

just thinking in the long run really if i decided to go single from a tt it may be cheeper to go from a N/A??

dunno really i suppose just keep it simple and have a tt and BPU it

An N/A to turbo, done properly, will cost mega money. It's a good move if you plan on building something WILD, in the 30K plus budget range, but if you just want a fast Supra it's madness, just buy a TT, they are cheap as chips, you can't do a decent N/A to single turbo CONVERSION for the price you can buy a TT for, IMO.

I have to disagree, if you are going to junk most of the tt bits then you may as well start with the na, lets face it most people that go single are looking for 5-600bhp, now i dont subscribe to the fact that the na bottom end is any weaker than the tt, a hell of a lot of guys in the us are running very high figures with a stock na bottom end (one even runs a 9 sec 1/4), it is just that it has never been done over here yet

The benefits of NA-T or TT aside I would say the sensible option for someone with no experience of RWD is to go NA, get used to the car at that level and then decide what you want to next.

..It's a good move if you plan on building something WILD, in the 30K plus budget range,...

Chris do you happen to know if th n/a exhaust ports are the same at the TT ports? You know, the way they 'face' the stock twins.

Chris do you happen to know if th n/a exhaust ports are the same at the TT ports? You know, the way they 'face' the stock twins.

No they are different

So the n/a head may be better for a single setup (at least in this respect)

i was thinkin about this as i drive a NA, some say its worth it some don,t and say buy a TT!! how much power can you safely go up to on a NA-T without changing engine internals etc?

List off Supraforums of peoples RWHP

NAME, RWHP, RWTQ, PSI

1) Ebanks: 981, 640, (?), 34 psi

2) SSSupra: 686, 559, 27 psi

3) 337: 660, 630, 30 psi

4) DaveH: 602, 501, 25 psi (75 shot)

5) Lex Luthor: 585, ???, 24 psi

6) Trd Supra11: 576, 525, (?)psi

7) SoAngel: 565, 513, 22 psi

8) 5spd_sc300: 505, ???, 23 psi

9) Oliver: 491, 494, 22 psi

10) Kbprice: 471, 446, 18 psi

As Bromy says, they are different. The N/A heads don't have sodium filled exhaust valves, either. Quite a few diffrences, but most would be binned or not be a problem on a seriously high BHP conversion. Let's face it, for a serious job you will junk a HUGE portion of the car, so you might as well buy the latest model, as cheaply as possible, hence a late N/A to convert from.

i was thinkin about this as i drive a NA, some say its worth it some don,t and say buy a TT!! how much power can you safely go up to on a NA-T without changing engine internals etc?

Not much at all, the pistons are far too high a compression so the first job is lower compression pistons. A thick head gasket is a real cock up. (He says, with one on his own Skyline.... )

how far have you gone with yours??

.. A thick head gasket is a real cock up. (He says, with one on his own Skyline.... )

The real cockup is two stock gaskets one on top of the other one.

(guess what, I've done this too:taped: )

Not much at all, the pistons are far too high a compression so the first job is lower compression pistons. A thick head gasket is a real cock up. (He says, with one on his own Skyline.... )

I know you are a clever guy Chris in to all your race engines etc but who can afford the likes of them, i would'nt say the gasket approach is a cockup, you shouldnt poo-poo something that works at a set budget

I know you are a clever guy Chris in to all your race engines etc but who can afford the likes of them, i would'nt say the gasket approach is a cockup, you shouldnt poo-poo something that works at a set budget

im sorry mate but by fitting a thick headgasket to a high compression engine to lower the compression ratio you are just introducing a weak link into the system.

ok it may work now and if you are lucky it may last a good long time but it will never be as reliable as some good quality forged low compression pistons

Thats why i said something that works on a set budget, me thinks you all dont like the fact of a na becoming quicker than your tt's

..you all dont like the fact of a na becoming quicker than your tt's

pretty funny statement, especially since you think that a turboed n/a lump would pass as a "n/a"

...but yes, if you insist, it's indeed jelousy disguising all the hype behind 'low-comp' pistons, injectors and other useless addons...

FFS give the guy a break, he is trying something different, wait and see how he gets on. His car at present is very impressive ( I have been in it) for what some would deem unacceptable mods.

Been considering the n/a-t route for awhile now.

I first bought my n/a due to it being my first rwd car and aswell as me only being 20. Since buying the car I have been saving and have enough stored away now for either a tt upgrade or the n/a-t.

I have been working out afew sums and it would work out more for me to sell up and got the tt route.

Insurance would be about £600 more (this is £600 on top of me declaring the turbo on my n/a)

I would have to wait to sell mine, which we all know the market of supes isnt exactly high as well as find the right tt for me. And for a decent one with the money i would probably get for mine im looking at putting about an extra 4k towards.

Plus, ive also spent nearly 2k on mine now maybe even more. And I cant be assed to pay another £80 either to swap my number plate over.

I know mines been looked after with regular services, loadsa history etc and things that have gone wrong I have sorted so im also getting my way round then engine abit too.

Obviously this is just my opinion but if I went back 6 or 7 months when I first was looking to buy a supe I would still go the route I have done.

Plus, I wouldnt swap it for anything simply because of the noise it makes!!

My tupence worth

i have the upmost respect for Bromy and the N/A-T conversion, its great to see people trying new stuff!

i was only saying imo a thick HG is only a temporary solution and that 'low comp' pistons would be ideal

n/a ---> turbo conversion with n/a pistons and purely relying on a thicker gasket?

Only for low boost applications, and then only if it's got standalone mapping. Otherwise I'll pass....

I am not criticising, I just said one my own engines has this to drop compression. The GTS-t RWD Skylines have high compression as their small single turbo has low boost and it's successfully designed to give early boost of a modest nature. the previous owner in Japan added a much bigger turbo, cams, injectors, mappable ecu, blah blah, but left the stock pistons in and dropped the CR by using a thick Apexi head gasket. It works fine, but it IS a cock up as the tight squish band (where the edges of the pistone almost touch the sides of combustion chamber at TDC, forcing turbulence into the mixture and moving it towards the spark plug) has gone, so I cannot run anything like as much timing as I could had the CR been dropped by different pistons or removal of material from areas of the combustion chamber. Power, efficiency and off boost performance all suffer `cos of this. A cock up. On an N/A engine with greater CR still, the head gasket thickness may well have to be even greater, with even wose side effects. It's surely bad enough when someone with plenty of dosh builds an engine that goes bang, but when someone on a budget does it it's even worse. I am merely pointing out that using a thick head gasket has bad side effects, and what they are.

Am I going to alter this engine? No, but it's cheap and cheerful, and I can map the ecu to get around the need for odd ignition timing.