I am thinking about building a crossover for a semi stock 3.1 N/A engine what will become boosted with potential upgrades & I'd like to pick some minds here.
The size tubing I'd like to run is 2" from each bank using the stock TGP manifolds joining to 2.25" or 2.5" collector going to a T3 flange then to the turbo of choice...
There is no turbocharger in mind currently, but t3 journal bearing something is the area of interest. Not going with anything smaller. Bigger? Maybe!
I know with too big of volume you could lose heat, velocity, and then power/lag. The thing I am trying to avoid is using too small of a dia in which might hurt possible future upgrades (Port work, valve sizing, turbo hybrid combination's, etc etc) . I kind of want to do this right the first time so I don't have to re-engineer what I come up with now.
Putting up with some future alterations is fine, I just don't want to have too many needed changes that will put the build-up at idle for too long...... Summer is too short as it is!
I know some would suggest going gun ho now, but I'd like to MAYBE see the before and after of this custom creation.
Discuss.
Wow, no one has experimented with this before?
Quote from: TGed on February 18, 2009, 09:06:00 AM
Wow, no one has experimented with this before?
If we had, most of us wouldn't still be on the stock turbo. ;) I know 300whp has been made through the stock x-over with a larger turbocharger installed...so it can at least support that amount of power. I don't think you need to go a whole lot bigger even if you're after a lot of power considering what can be pushed through the puny stock x-over. I'd maybe take a look at what the 3X00 turbo guys are running in J-bodies, etc., I know several of them are making pretty good power these days.
I've read and looked at a few threads about a lot of 660 owners making crossovers. Most stay the same not giving it much thought. What I'd like to find out is the size of a set of 660 headers crossover. It would possibly give me some insight.
I just dont want to leave it stock IF I can gain some spool up time and reach peak power sooner. I think I am going to have to be Christopher Columbus on this one.
Quote from: TGed on February 18, 2009, 09:06:00 AM
Wow, no one has experimented with this before?
I have found that it's best to have lots of velocity before the turbo. You achieve this best with smaller od pipe, Less lag.. After the turbo bigger is better... ;)
Well the pipes are ordered and I will be ready in about 2 weeks (about when they'll come in) .
15.00 shipped for 10 mandrel bent J bends, can we say DEAL. I'll leave the size unmentioned for now. Keep ya'll thinking!
I wrote the size down for the stock x-over somewhere around here, until I find where I put that note pad, does anyone know or can measure the stock size x-over for me now? Thanks in advance.
QuoteAfter the turbo bigger is better... Wink
I know that, that's what the 3.5" mandrel bends are for... Had those pipes since last year! lol
Now I just need to purchase some other parts and play the modification game!
This should give you a good idea of the stock x-over size.
(http://home.alltel.net/mfewtrail/images/flexes.jpg)
At the price you paid, it sounds like you didn't go with a good grade of steel...so your custom x-over probably isn't going to last real long. As small as the x-over is, it's not real expensive to go with 409 or 304 SS.
I am using header bends made for V8's . They are 14 or 16 gauge steel, I forget which. People use 18g all the time for home builds without issues. I figured with added heat I should go thicker.
Thanks for the pics!
heres mine...
(http://i22.photobucket.com/albums/b342/kuntzie_86/turbostuff003.jpg)
(http://i22.photobucket.com/albums/b342/kuntzie_86/turbostuff004.jpg)
(http://i22.photobucket.com/albums/b342/kuntzie_86/turbostuff006.jpg)
doesnt that stuff need to flex?
no it will be fine, there is a flex in the exhaust but its not needed on the x-over, its not like its one solid piece
specs
2.25" ID stainless, the manifolds are a thicker ga. stainless, the flanges are 3400 flanges incase i ever use these on a 3400.
the wastegate is 60mm or ~ 3"
notcheap but they will last forever
Have you ran it yet with the 2.25" ? Hows the spool up time?
you have seen my turbo right? it spools around 3000rpm
I think I have. That is good info for what I plan to do and how I plan to do it.
Have any issues with boost spike currently?
the 60mm wstegate apparently is working well to regulate the boost., i havent seen the car is over a month.
(http://i22.photobucket.com/albums/b342/kuntzie_86/turbostuff111024.jpg)
(http://i22.photobucket.com/albums/b342/kuntzie_86/turbostuff111023.jpg)
Sweet!! Where did you get the flanges for the 3400??
from 60*v6
Figured I'd give some in depth physical evidence on how small the crossover really is. :icon_sad:
Have some good and bad news.
Bad: GP is not the project car of choice anymore
Good: I kept the motor sold the car and paid some bills off.
Good: I already have the car of choice getting all this treatment. The car is a 88 Beretta. Still an old GM product!
Bad/Good: The crossover plan didn't get underway before the GP sold, so I started AND finished 90% of the crossover!
I welded up everything for the crossover, just waiting for the item to git back at me for me to install it.. You'll like the end result. If not, oh well! :icon_razz:
I'll try to keep this updated more often if there's a reason too.
Update:
It is what it is, let me know your constructive opinions. :-)
Yes the battery is relocated and yes that is ceramic coating. I am going to wrap the pipes with some DEI to make sure all energy is going into the turbine housing and not the engine bay.
Hopefully next week everything is all ready to go for install. I just hope the trans doesnt shit the bricks. If it does, I have Plan "T" for it. Poor 3t40, it just will not know what is going on when everything is done.
I give it a week and the trans is toast.
No one interested? Ok.
looks good to me... where is the downpipe running? should go strait out the fender.
I'll let the pics speak for themselves when I finalize that out next couple of weeks.
Some parts came in a couple days ago, and next weekend I'll make for special time for that special car......... :ugh:
you got me thinking, i talked to my local welders about making me a 3" DP , also getting the crossover rebuilt and going to have him use slightly larger pipe to help the flow. dropping off a spare 3.1 as a jig so there no question of a perfect fit. :yakyakyak: how small is the old crossover ... 1.65 ??
I posted up some attached images above. It should give you a rough idea. It's actually smaller than the stock 3.1 NA xover.
i have been making some progress as well. guy called me today and said the dp was nearly done, reused and choped the original flange to cut the restriction out and used 2.75 back. should make a good improvment over stock. also he not going crazy with the crossover just basic repair where it needed, only one flex bellow was cracked so i dropped him off a na 3400 crossover which are great to reuse the bellows from. monday or tuesday! cant wait.
well the progress came to a mere finish. I MIGHT have to adjust the exiting portion of the tail pipe, but I dunno...... Maybe some slightly taller tires coughslickscough will allow for some ground clearances.
No vids since I dont have a digital camera anymore (they break soo easily!) , but just know, it is super duper uper loud WOT and really fierce but not too loud at idle.
Cliff notes - Exhaust might need adjustments, sounds aggressive and fierce.
Slight update........ (http://i937.photobucket.com/albums/ad220/accountpictures/Auto%20Repairs/GM%20-%201/Cracking2.jpg)
When you see it you'll crap bricks.