Full-race's new toys
Evolving Member
Joined: Jun 2004
Posts: 371
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From: Australia
Hi Geoff , is this a Honda head thing or is it a typical for well developed TS turbo engines to have the torque lines closely follow the Hp ones . My guess is the large VE gains from the divided system and the benefits of four pots vs more pots .
Cheers A .
BTW was the "37R" a BB P/67 type thing in a T04 housing ?
Cheers A .
BTW was the "37R" a BB P/67 type thing in a T04 housing ?
To be honest, what i was really trying to show here was the spoolup differences between the turbos, the peak power on the dyno plots doesnt matter. Once the wastegate opens the torque curve levels off. what we should be focusing on is the activity while the wastegate is closed (the spool)
Geoff, can you give us an idea of boost pressures? Fuel? Were they the same in all tests? I ask because the GT35R with the larger hotside gave better power figures than the PT67R, which doesn't really happen when all else is equal (not that it really makes much difference here).
I find it amusing however that the GT4094R with big TS housing outspooled both of the others, then mopped the floor with them power-wise.
I find it amusing however that the GT4094R with big TS housing outspooled both of the others, then mopped the floor with them power-wise.
here are the results of the cam test we did today using the 4094R and C16 at 17 psi. the solid line is some big cams, dotted line is the stock ones.
and the boost plot
Below is the 93 octane plot with the stock cams at 14 psi
I'm impressed big time with the graph you posted Geoff, but the results from this EVO poster aren't as impressive to me. Here is the link to the thread too the post is on the last page. I asked him to post his full setup because I would expect a 85lb wheel to put down more than 685whp.
https://www.evolutionm.net/forums/sh...d.php?t=253110
https://www.evolutionm.net/forums/sh...d.php?t=253110
Hi Geoff , is this a Honda head thing or is it a typical for well developed TS turbo engines to have the torque lines closely follow the Hp ones . My guess is the large VE gains from the divided system and the benefits of four pots vs more pots . BTW was the "37R" a BB P/67 type thing in a T04 housing ?
the 37R is a bb p/67 in T04S compressor hsg and T31 .63 4 bolt turbine hsg
Last edited by Geoff Raicer; Aug 21, 2007 at 11:24 PM.
oh i forgot to mention one more thing, with the new cams the car did 690whp at 23 psi (C16 was used for this)
and the boost plot
the clutchmasters twindisc was slipping after this and the customer said he doesnt have enough $$ for a new clutch so it was left like this
and the boost plot
the clutchmasters twindisc was slipping after this and the customer said he doesnt have enough $$ for a new clutch so it was left like this
Last edited by Geoff Raicer; Aug 22, 2007 at 07:35 AM.
1) twinscroll 30R
2) twinscroll 40R
3) twinscroll 35R
4) twinscroll 42R
If the all around powerband is that much better than i would tend to think the twin 37r would be the shizzle with a 2.3
I love reading about new and better stuff....keeps my work day going!
I love reading about new and better stuff....keeps my work day going!
when I get my 4088TS from you I will be running 37psi
I really think the 40R is the turbo that will be the one to use. Its basically an ultra efficient 37R, but becuase its twinscroll it spools even better than a 35R. It comes into boost so smoothly and so strong that even at low rpm it is very responsive and doesnt feel like a 700+whp turbo, even though it definately is.
On one of my personal cars i went from a GT37R to a 40R, the difference was night and day. The 37R was dead until boost hit, then it TOOK OFF. huge power increase in a cpl of rpms. The Twinscroll 40R had great power at lowish rpms, and when you rev the engine is just jumped. As you started driving it it would go right into boost, nothing at all like the single scroll 37R.
<im sure your boss loves evoM>while the 37R will work well in a twinscroll configuration, my belief is that the (2) GT40Rs are better choices. The GT4088R is actually a smaller turbo than the 37R, but it has a 10 blade turbine wheel which is more efficient than that of the 11 blade 37R turbine. The GT4094R is a slightly larger turbo than the 37R and it still has the same 10 blade turbine wheel, but is capable of more power due to the larger flow of the compressor combined with increased turbine efficiency.
The new 2007/2008 Garrett catalog has an exceptional intro to turbo sizing and how to properly work with compressor maps on pgs 8-11. If you have some time and a good calculator (or an excel spreadsheet) you can really learn a lot. Check it out if you have some time. Id be happy to help answer any questions you have once you start plugging in #s and working with the maps:
http://www.turbobygarrett.com/turbob...007Catalog.pdf