turbo specs & results

[tubbyG]

I want to upgrade my turbo later this year to get the most out of the 285 cam, but im unsure on which exact spec to go for.
I would like something much bigger than the T2/25 I currently have such as a T28

so what spec's do you guys have and what results have you seen, either 1/4 times/speed or RR figures


nice one:agree:

[newbstar*]

vnt:)

[5teve L]

I had a T25 with a .49 rear 12.78 @ 109mph 1/4 mile & over 200bhp.

[James5]

I personally would say VNT on the c1J with a 285 cam:agree: but as I know how hard a VNT is to come across and having been in Steve's previous 5 the T25 spec he had was very nice and good results

[GTphil]

Although the spec of the turbo obviously has a huge effect on the power a c1j makes there are other aspects that also contribute,

Compression ratio
Cam spec/timing
Ignition timing
a correctly tuned carb or indeed efi (if your posh)

My car managed to do 106mph terminal speed at pod with 22psi boost on a t28 with a .49 A/R and a cosworth comp housing (can't remember which one)

I have a 112degree 285 timed to 116 degree retard and slightly lower than standard comp,standard ignition timing, fueling low 11,s afr over the line.

That should be just a shade over 200hp:-D although some people have had much better results with smaller turbos and less boost it is more than likely down to some of the above mentioned things or a combination of all of them.

[tubbyG]

Vnt would be awesome for sure, I know they are pretty rare also. Does big Jim still make them?

Im not overly fussed about lag ( well within reason) as I plan on keeping my current carb and turbo as spare for a low lag/fast road setup.

Thats why I was leaning more toward a T28