Test drove a customers car today thats running an MDX555-450 plus a lot of other mods (ex scoobyworld car) and it was alarmingly disappointing.

The car is a 2003 Blob STI and my main concern is that it doesnt deliver anything til 4500rpm, is that right??

Other mods on the car are
650cc injectors
Turbo smart 3 port
3" ninja system
apexi induction kit
HDI front mount with the worlds longest fmic pipework!

Apparently its mapped by scoobyworld to 400bhp but after driving a 2.5 360bhp blob I doubt very much that its much over 350.

Is the 555-450 a good turbo for a 2.0, should it deliver lower in the rev range and what potential does it have? We've suggested getting Duncan Graham to look it over and remap but would like to get the guy more info before we book it.

Any help is appreciated.

 

I'm sure that's a very old turbo that's really laggy? To give you an idea mine is about 680bhp and it hits full boost 2.3bar at 3600rpm and people say big power cars are laggy I bet that turbo didn't come on song till about 4500rpm? and if its not an STI there isn't much rev range after that.

 

yeah 4500 rpm, then it delivers but is hardly mindblowing. They claim its 400bhp @ 1.6 bar but I doubt that. The car is an STI and it does move once its in boost but you have to ring its neck everywhere to get any enjoyment out of it and have to constantly drop gears to feel anything.

Would an MD321T be a better alternative for him, or a good 20g?

 

Modern turbo's with a billet wheel would transform the car, I would look at the Scoobyclinic range but it means an extra £2k on the car with new turbo fitted and mapped so is it worth it?

 

Yep they are like that. Make good power with lots of boost

 

I bought a 555 some years ago, and out of advice from a mapper I sold it and went for a standard fit GT30 on the 2.0 avcs. So I can't comment on the lag, but I was told it wouldn't be ideal unless redlining through the gears, that I didn't like. Oh and the GT30 was a little laggy on the 2.0 too, but made decent power before 4'000 on a serious budget bhp chasing car

 

ok, so basically nothing is going to get rid of the lag apart from a turbo swap unless he rings its neck everywhere.

No sure theres a huge budget on this, a better driving car with safety/reliability is what he's after, not number chasing so what would a good budget turbo be for it?

20g?
321T?
VF48?

 

20g a proper one yes, many copies about at the mo.

Vf48 tends to lend itself to 2.5 better than 2litre.

Md321t works well or md321h

 

If it's fast spool he wants then maybe consider a twinscroll conversion?

 

A twin scroll SC42 is just about the perfect turbo for road car. Even on a front mount it boosts nice and low and gives good power almost to the limiter.

 

A modern turbo will spool as fast as a twin scroll conversion and be much cheaper.

 

yeah he wouldnt want to go twin scroll

 

Twin turbo conversion? One small one big??