partshipperdave

iTrader: (17)

lowrider, no comment. thanks for sharing.

Beeker

iTrader: (5)

I finally installed them today. If you are going to install headers yourself make sure you have a 14mm ratchet wrench. I can't imagine installing headers without one. If I was to do it again I would remove the coolant pipe on the passenger side. It would make it much easier to get to the bottom middle nut. Also, if any studs come off when your removing the stock manifolds renistall the studs before installing the headers. Normally you can just screw them back on with the nut attached but there isn't enough clearance to do that with headers.
Besides that, it is a pretty straight forward install. Its just very time consuming, tedious and annoying to do!!

My first impression is there is a nice gain in the mid range. It seems to pull much harder from @2800 rpms to redline. It does seem to have the strongest gain in the 4000-5500 range. I can't really tell a big difference up top. I think the stock exhaust is holding me back from a bigger gain in the top end. I haven't noticed any loss anywhere. In fact, it seems to have increased low end tourque.

I have only driving with them for about 30 miles. I will post again in a few days when I put a few more miles on them. I can tell you that there is now a lot more heat in the engine compartment. I don't think it will be a problem but it is very noticeable when you open the hood.

I do have a few questions. Should I reset the ECU? Do the header bolts normally need to be retightened after 500 miles?

partshipperdave

iTrader: (17)

Hey Beeker,

Glad to hear you got the Strup headers installed without too much hassle. True, it is a straight-forward install. no real magic there, and the 14mm ratcheting wrench is definitely the tool to have for this job. I think it's a worth while mod for the DIYer too. Gets you intimate with what's under the hood, and also a sense of accomplishment... that and it saves you dropping hundreds on having a shop install them for you too! ;o)

Let me know when you get the dyno run done. Looking forward to hearing back from you. As for tightening the header bolts, yes, it would be good to retorque those bolts around the 500-1000 mile mark. Other than that, enjoy the power!

Beeker

iTrader: (5)

I will retighten the bolts after 500 miles. I doubt they will loosen up but I guess its possible. The nuts that hold the headers on are lock nuts. Thats why it takes so long to get the stock manifold off. You need to use a wrench to turn them until they are almost all the way off the stud. I don't know how I could get a tourque wrench in there. I just tightened them as hard as I could with the limited space available.

I resest the ecu this morning figuring it couldn't hurt.

I must say that I noticed the increase in top end this morning. I bounced off of the rev limiter much faster than I am use to. It seems to pull much faster and harder towards redline. After I put a few hundered miles on them I wll recheck all the nuts then get it dynoed. I will post my results once its done. I would say in about two weeks.

partshipperdave

iTrader: (17)

nice! glad to hear you're appreciating the gains. Keep us informed when the dyno test happens.

Nismo 350z

I have the DC headers ceramic coated ones. The most power and tq. come from the headers. I also have it coupled with a pop charger and a nismo exhaust and its really loud at WOT. But yes headers are definatley worth it. DC ones are the only CARB legal ones though and no you dont need to jethot them unless you plan on tracking ur car alot ( like every week).

the7ferret

what does the carb certificate look like?

Nismo 350z

They give u a sticker.

Beeker

iTrader: (5)

I just made an appointment to dyno my car tomorrow night. I will post my results as soon as I get back.

davidv

iTrader: (2)

DELETE

1991TT

....and a set of slicks.

Beeker

iTrader: (5)

Ok. The results are in. I dynoed tonight.
My best run, SAE corrected was 247.63hp and 241.68tq. I put down 228.56hp and 221.91tq SAE corrected before I installed the Strup headers. That is a huge increase! I expected a gain but not that much.
The gains are also across the entire rev range. There is no loss of power anywhere. The tq increase is between 15-25lb ft everywhere, with the biggest gain between 3700 and 5000 rpms.

The only modification difference was the headers. I had the Popcharger installed for both runs. I should mention I changed the oil since the baseline. I did have Mobil 1 10w30 for the baseline but Mobil 1 5w30 for the run with the headers. I switched to 5w30 at my last oil change because temps are starting to drop in RI. I doubt the difference in oil weight would make a big difference but I wanted to give as much information as possible. I should also mention I use 93 octane pump gas.

The AFE actually improved with the headers. It ran slightly richer with them. Which I was happy to see because I was already running high 13's between 4000 and 5500 rpms and I didn't want to get any leaner. I thought headers would have made it leaner but I guess I was wrong.

I will post the dyno sheets as soon as I have a chance.

A lot of people have been waiting for an independent, before and after Strup header install, dyno. Now you have it. Who ever appreciates it send me some money to cover the $75.00 dyno fees!

knicksinny

iTrader: (3)

What was the temps with before and after runs. Seems like some nice gains. I bought a set of these headers but have not put them on yet because I am debating turbo.

harrieyu

iTrader: (4)

what are you going to do with the headers if you go fi??? sell them to me!

kosmic

Thanks for tha report, Beeker. Maybe colder weather had an impact on your dyno, but even so those are good gains. It was the same dyno as the first time, right?

the7ferret

can you post a pic of the graph?

Beeker

iTrader: (5)

Yes it was the same dyno.
I ran three runs and the last run was the best. The first run had interference after 5200 rpms so only two of three runs have complete charts. The place I had it done at emailed me the charts but I can't get the program he sent me to open them. I do have a printout of my before and after best run. I will scan it later on tonight. I don't know how to post a pic so someone will have to host it for me. I will email it to partshipperdave since I told him I would. He should be able to post it.

The temperarture was about 15 degrees colder in the dyno room for the header run. I believe it was in the high 70's for the baselne and in the mid 60's for the header run. Those were the temps in the dyno bay. I am sure that made some difference but I thougt SAE correction compensates for temperature differences.

I must say that I am more than happy with this mod. I can feel the difference and now I have the proof. Yes, they are time consuming to install but its hard to complain about such a large gain for a bolt on.

The place I had it dynoed at is moving to a new location at the end of the month. It will be the same dyno so hopefully when I go to their new locaton, after installing a few more mods, I will have comparable charts. I am hoping to get into the 260's after I install Motordyne's plenum spacer and a Borla TD exhaust. Winter is coming to RI so I may not get it back on the dyno until spring.

Satans350

iTrader: (5)

nice gains? makes me want to get headers and a y pipe. I recently installed crawford high flow cats and i thought that was a huge difference. so being in CA my only choice would be DC headers??

partshipperdave

iTrader: (17)

Here's the chart that Beeker sent to me earlier this morning for you all to drool over!



Fall sale is still in effect!

https://my350z.com/forum/showthread.php?t=146062

PM me with any questions.

Nismo 350z

Yup in CA only the DC headers are the ones you can put on without getting harassed by the popo.