but recently I’ve been talking to a tuner out in rochester who is a big fan of the GT3071R, as he put it, the turbine wheel has been clipped to fit into a T28 housing which gives is spool as quick as the GT2871R but with a bit more power.
I haven’t had time to punch in all my info into the maps of both of them to compare but I was wondering if anyone had more info on the two for me. Just at a glance it seems like the 30 puts out a bit more airflow while still be rated for only 480hp (GT2871R is rated for 475)
I guess I’m asking how much of a difference is there? If they’re so damn similar than why should I bother buying the 30r. If the 30r does put out a significant amount more power, then how much spool am I really loosing on my 1.6 at 1.5 bar?
Well I cannot really speak on behalf of these spools on honda motors, I can say the spool characteristic on the flat sixes is negligible between 28’s and 30’s. maybe 150-175rpm if that, and so small that’s it’s far outshadowed by the additional power made on the p-cars over the 28’s.
I have no idea how close tot he choke you’d be on a 28 in your setup that may or may not show the necessity for a 30r comp wheel.
hrm, looks like what your saying is that it can make more power on top and spool at nearly the same RPM …on larger motors.
I guess I’ll have to start punching in numbers and see where they fall on the maps. Even if the 30 offers a slight advantage I’ll probably keep the 28 since I already have it.
the 3071 internally gated turbo is a great turbo even for a 4cyl. it’s more efficient than a 2871. We decided to go with the 3071 for my coupe because it’ll flow better, with less heat.
get a .86ar T25 3071R… but honestly if i were you just go t3, open that new door tot he T3 frame. get a 3076R, with a .63ar exhaust housing. like the T3 3071R it uses a 60mm turbine wheel, vs the 2871r and the t25 3071r that use 53.8mm turbine wheels… i have a T3 3071r 60mm wheel, 25psi at about 4000rpm in 4th gear. 4200 in 3rd. in 6th gear at 65mph(3000rpm) i have 10psi almost instantly. the 3071R t3 really wakes up around 18psi, im not sure what you plan to run, but the turbo is very efficient in the 18-25psi range.
honda engines have a high VE, so luckily you benefit from any amount of boost. on a GSr, a 3076R you can make 450-460whp at 16-17psi which is ridiculous
I don’t think I’ve ever had a solid running setup since it was stock. But that’s in my opinion. I always want to change and tweak things, its just the way I work. Last summer the car was out and practically done, and over the winter I got itchy for a project and got in over my head…
I do have a couple manifolds and downpipes, and since I was planning on changing from the GT28RS I figured i might as well go V-band with the turbo/downpipe and finally go external wg.
anyway… my question here is how comparable are the two turbos? the GT28RS was great and had fantastic spool, the issue is that on smaller courses and slower corners I had a hard time preventing the tires from tearing loose. while on moderate length straights in higher gears I definitely could have had more power (and my motor supports more power and boost).
Hence the tiny step up to the 2871R, and after the comments from this tuner, the interest in the 3071R.
I actually just found this dyno graph, bone stock SOHC motor on race fuel. Solid lines represent GT2871R, dotted are the GT3076R divided housing/manifold
It doesn’t exactly show what I’m asking about (GT3071R), but with my built motor/head I should be at that on E85
