MyE28.com DEV

I guess I'm bored,since I'm looking at datalogs. It occurs to me we have a lot of megasquirters who could post datalog info such as what rpm they pass atmospheric,2#,4#,etc.This might help to really compare different turbo characters. Of course we all know load enters into boost thresholds. I was thinking if everyone would do a datalog of a 3rd gear pull on level ground and post RPM.
mine are

atmospheric=2923rpm
2#=3007
4#3089
6#=3182
8#=3287
10#=3354
12#=3412
14#=3505
16#=3567
18#=3727rpm
this is an 84 m106,k27 turbo,w/ m102 jetronic wastegate.
marc

ok I get it now. The ##### was alittle confusing.

So you want to see a log from a roll in 3rd gear?

Right,3rd gear rolling about 30 on level road, then nail it.
I would love to see how different setups spool.
marc

Diff ratio is important.

I'm running a 3.45 diff with 255/40/17 tires. I'd like to try a little taller tire as I think I have the torque to pull it. I just don't want to loose the ability to light em up.
marc
p.s. I'm not trying to start trouble, I know a lot of turbos will make more hp,obviously a larger turbo spools slower than a small one,I'd just like to compare notes.

Just wanted to point that out because a taller diff can make the turbo spool faster due to higher load.

I noticed in a 4th gear pull that I can cross atmospheric at 2100 rpm, but then boost builds slower.

mooseheadm5 wrote:Just wanted to point that out because a taller diff can make the turbo spool faster due to higher load.

it´s not higher load. It´s worse gearing making the low output accelerate the car slower giving it more time to spool in the gear you are in .

Heres an M20B27 around 8.2:1 CR with a GT3582R .82:

Crosses atmospheric 2726 RPM (throttle plate is only 32% open)
2# 2860
4# 3105
6# 3417
8# 3550
10# 3672
12# 3766
14# 3841 Wastegate opens
16# 4700 Boost begins to creep
18# 5300
20# 5617
22# 6000
24# ~6500