Nitrous revisited....with no explosions :-)

The planets finally aligned and was able to get back on the dyno to play around . This is the same car that backfired and blew the intake open a little while back.

Run with no nos


.020" jet


.030" jet


.040" jet


.050" jet


.060" jet. Don't knot what exactly happened here.... Maybe dyno shock? Either way, out of diesel.




All runs were made on the same conservative superflow dyno as before with runs going from 35mph to 115mph taking 15 seconds in 4th gear. Tried to hit the nitrous switch at ~3700rpm each time. Only one run was made for each all back to back. To further advocate how vital head porting a cam is on a tdi, notice how these dyno plots actually cross at 5252rpm while still making power .

On a side note, car is running the new ARP tdi specific head studs. Seem to be doing the job great. Coolant bottle was checked for pressurization after each run with none found.

keep up the good work man !

Nice work...

on a side note, EVERY dyno plot will read exactly the same hp and torque at 5252rpm, regardless of the setup.. It's just math at that point..

Oh yeah, I suppose I should probably put in a mod list haha .

2002 ALH
.5mm ASV pistons
IE rods
12.9 caps crews in main caps
ARP head studs
11mm
R520's
S/T 1856 turbo
eurojet fmic
one of my intakes with matching turbo inlet pipe
one of my 2.5" dp's with straight exhaust
head porting by me
Colt stage 2 cam
TT valve springs
NX dry kit
Malone tuning

TDIJetta99 said:

on a side note, EVERY dyno plot will read exactly the same hp and torque at 5252rpm, regardless of the setup.. It's just math at that point..

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Mathematically they all should, but very few tdi plot's actually do cross at 5252 while still making power. Usually they cross after both curves have fallen way off. This thing was still building power at 5500.

Ya still building power at 5200 is nice.. Most TDIs have already begun the downward turn by that point..

Whitbread said:

Mathematically they all should, but very few tdi plot's actually do cross at 5252 while still making power. Usually they cross before after both curves have fallen way off. This thing was still building power at 5500.

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The reason they don't normally cross is due to scaling. Think about it: hp = torque x RPM / 5252. So, at 5252 RPM the multiplication and division cancel out. If they don't cross at 5252 and the scaling is the same for hp and torque then something is wrong.

vwmikel said:

The reason they don't normally cross is due to scaling. Think about it: hp = torque x RPM / 5252. So, at 5252 RPM the multiplication and division cancel out. If they don't cross at 5252 and the scaling is the same for hp and torque then something is wrong.

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That may very well be. I don't have any other tdi dyno's in front of me to look at the scaling. I gotta go out and put together my 700r4 for my big chevy though so another time. Either way, still not common to see a tdi still building power above 5k. It obviously wants a larger turbo.

Sweet! Is it normal for the trq to drop like that with nitrous?

Yeah your plot has both HP and Torque (in lbf-ft) on the same y-axis. Most other dyno plots have HP and torque on separate vertical axes... with different scaling.

A better way to say it might be, look how god damn awesome my HP curve is at high rpms! This thing must be a blast to drive. Planning on any 1/4 mile runs?

I applaud anyone for testing performance TDI parts, but I don't like your dyno. It's low, but I'm not sure how much LOL. It makes it hard to compare this setup to anything else.

I was on another site, and someone posted a dyno sheet. the sheet had HP and torque crossing TWICE. I called BS on the sheet and it lead to a big flame war...Hehe


/coolstory.?

looking good.. did you adjust mapping each time between a run or used some evry mod to increase fueling? or was it just hugely overfueled without nitrous?

Rub87 said:

looking good.. did you adjust mapping each time between a run or used some evry mod to increase fueling? or was it just hugely overfueled without nitrous?

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I'm pretty sure Mark has the tune pretty well maxed out in the fueling department at WOT. That's a question he'll have to answer though to be sure. No changes other than the jets were made between runs. Between 26psi, cam, intake, and porting, it really doesn't smoke terribly at WOT without the nos. Definitely smokes, but I wouldn't call it death clouds by any means.

bring that nitrous in a little sooner next time..

also if you do start playing with it more see if she starts rattling at all..if she does run a little less timing on your nitrous tune.

crazy that you gain over 50hp without injecting more fuel.. nice

Whitbread said:

That may very well be. I don't have any other tdi dyno's in front of me to look at the scaling. I gotta go out and put together my 700r4 for my big chevy though so another time. Either way, still not common to see a tdi still building power above 5k. It obviously wants a larger turbo.

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Yep, def. needs a big p/s hybrid or 2359v or similar....or maybe just throw 12mm head on it and try .070 jet...either way it should rip a good 1/4 mile time since it builds power quite well at upper rpms....provided the 02J holds up!

Matt, is this the new 1856 from Kerma?

silverbox said:

Matt, is this the new 1856 from Kerma?

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This is the latest iteration of the 1856 from Nick @ Street Toys


This turbo seems to be on par with the VNT 20 I had before

Hey Matt, thanks for 2.5 in exhaust I just got on Wednesday. I'll write a review when I get the rest of the IC piping installed.

Impressive numbers. However, as Jason says, all HP/torque curves will cross at 5250. I know there are two sets of numbers here but the ones that go above 5250 cross.

This is a stock block and head.