I'm a huge fan of your engine bay, especially the wire tuck. Easily one of my favorite RX-7s. Well done body kit and functional yet visually appealing ride height. Not too many guys left that have been in the FC game this long and still progressing.

 

Love the work you have done. Where did you get the bonnet?

 

Thanks mate. I don't think most people on these forums understand half the time and work that goes into a proper wiring tuck. If I did it again Id just go a ISIS system. And yeh only a few of us left that have had these toys for over 10+ years. For me its always but been a toy and something to play with. At least my wife understands. (was one of the rules when we got married that she couldn't force me to sell it, and any of out houses that have double garages are mine and for the Rx7 only :P Next house will need to be a 4 car garage if I want my daily and her's under cover


Thanks, bonnet was a one off from Dltreezan back in 2006 (from this forum) I not sure if his still about. It was a bit of issue when I got it, I ended up having it remade. But the end results Im still very happy with.

Anyway Cars at rotomotion for a tune... so say I'm excited and Nervous is a understatement !

 

ok Dyno run was a fail...

They were doing the power runs and its spiking up to 28 psi !

they think they found the issue (fucked braided line somewhere) so their going to replace it and have another crack tomorrow.

 

Engine still ok ?

 

yeh sounds like it, they didn't seem to stressed, will wait to hear the results tomorrow.

 

I would still ask for a compression test...

 

Had a chat to this this monring. They replaced the line and its still doing it.

So looks like its a wastegate runner placement / manifold issue.

Looks like this setup (new block and turbo) just flow way so much more their's a issue, where as my old turbo and stock block never found the limit to the manifold.

So if I have time and its not to hot over Christmas (is meant to be 109 farinheight on Christmas day here !)

I might try and pull it all off, get the manifold tweaked (might even have to run dual WG's that I never thought would ever be required) and see how we go.

So the build takes another ... direction :P

-Anth

 

I've seen that before . Wastegate runners need to be in the path of direct flow on a single wastegate. Put in some race gas and let's see what it does at 28psi.

 

hahaha, lets get this issue sorted first and then we can play

Graph shows it fairly well. I'll chat to my fabricator just need to reconfigure the WG runner locations. (or run dual WG's I guess)



Will keep everyone posted

 

Its definitely the manifold design. Isn't it funny how many people on and off the forums are running a similar design without any boost creep? Just goes to show you how poorly setup most people's cars are...

 

Aggreed,

So Ive being doing some reading, I haven’t spoken to my fabricator yet, I will in the New Year, but I thought I would ask some quick questions.

Is there normally an issue with the WG runner location? Or just a blockage of flow of the WG runners? (at were is collects or the WG ?)

It does look like the original manifold I’m running is a “china spec” of some sort, in saying that it’s been running fine until now for the past 7+ years and until now I’ve never had an issue.

It still a bit confused that it’s now generating this issue at such low rpm. Even with a new block and better turbo = more exhaust flow. It also has a smaller exhaust 0.85 housing (at 200 hp) that now got a boost creep issue, compared to a to4e at 350hp at 7500 rpm at 13psi with no boost creep? (which would of had 2x the flow )But it did have a 1.15 exhaust housing and only a 3” dump (new dump is 4” now)

So I’ll check the WG and the pumping (it is opening currently as it’s got a screamer on the dyno)

But I guess theirs 3 solutions and I’m curious what the best is, what’s cheapest, and what just won’t work. (Considering I know I could just get a new one fabricated but I’d like to just modify the one I have)

Original:




Similar with view from top



Option 1:
Keep existing WG runner locations
Cut end off existing WG runner pipes before the merge
Redirect 2 new WG pipes and run duel WG’s
(Cost – $400 for another 40mm WG, $200 Fab, $100 new braided lines and fittings for 2 WG’s)



Option 2:
Cut off existing WG runners.
Seal up old openings.
Have new fabricated runners put on.
Have it still merge into one WG.
(Cost – $400 Fab ?)



Option 3:
Cut off existing WG runners.
Seal up old openings.
Have new fabricated runners put on.
Have a WG runner for each and run dual WG’s
(Cost – $400 for another 40mm WG, $400 Fab, $100 new braided lines and fittings for 2 WG’s)



Any other idea's solutions are most welcome. As its a right hand drive car clearance is a ***** !

And before anyone says its your crappy WG, its not that setup any more, its a tial 44 MRV.

 

There's pics floating around the forum here of people cutting some of these ebay manifolds open and finding the holes leading to the wastegate tubes the size of a dime at best and they look like they where just blown open with an oxy/ace torch. Wouldn't doubt that would be a good culprit to your boost creep issue apart from the noted poor wastegate tube takeoff locations.

 

Its not., its good open gantries that have all been die grinder and cleaned up.

 

Both options 1 and 2 should work assuming the new tube for the rear rotor(blue) connects to the outside radius of the main bend( So if you looked directly into the inlet of the rear main runner, the WG entrance would be a direct shot). The main problem with your current manifold is the w/g runners connect to the main pipes @ right angles to the direction of main flow. The wastegate runners need prioritization. Option 3 will for definitely work again assuming the new pipe meets above criteria. The reason you are seeing this problem now is you moved to a 4" downpipe. I have seen this scenario countless times infact I've got a 2nd gen here currently that has the exact same problem. I thought I sent you a 1.0 housing for your TDX61?

 

boost coming back on that radical with that tune isn't from creep.. come on, it's making 200 at nearly 20psi. even with a good tune i'd be looking more at a hanging up wastegate or improperly setup boost controller seeing how it is ramping up as if the WG is closing back up or just too small.

 

Sorry yes it was a 1.0 housing (should be )

I put compressed air into the feed line (off the turbo pickup) and the WG is opening all fine (can hear it click open and close as required) - I thought it wouldnt untill the boost controller had power ?

But regardless thats still not the issue is it, its flow. (we all know its opening just overboosting)

So it has to be runners.

Ive attached some other pick's. I think I dont need to modify the rear rotor pipe, it comes off at 90 to the side of the flow, that should be fine (enough other manifolds are like this - and yes I know it would be nice to come more angled into the flow, but it will hit the dump pipe.)

The other that comes off the front rotor is actually squashed a bit, as that's were the manifold pipe size gets reduced down to suit the split paulse in the turbo flange. So that has a reduced flow area. Im thinking I cut that one off. and get a new WG runner that comes almost directly off the top of the runner as it comes out of the engine. Ill just run another WG regardless I think.





Can I ask why a 4" dump would make it flow less (as it needs more out the WG ?)

I still want to go for a drive tomorrow (well after the work christmas party hangover goes away) and test to see what rpm I do at 110 and 130 in 4th. because to think it spools up nearly 35km/h sooner then my last turbo is stupidly good !

 

Care to elaborate ? (as I said before I need to go for a drive to see what the 140km is in rev's

(comparing to my old 60-1 dyno in 4th gear)



Its not tuned yet, they cant get a run without it overboosting.


Well its a open WG. you can tell its not closing up again easy enough. a Tial 44mm should be enough for this setup I would of thought (+ where not talking 7000 rpm here - this is all happening before my old setup even use to make boost ! )

 

Again the problem is the waste-gate runners connection angles to the main runners. The problem was hidden before with a small exhaust system with too much exhaust back pressure, and a poorly sealing engine. Off the top of my head I can count 5 manifolds I had to fix that did the exact same thing. I ended up adding a 2nd Tial 44mm and the problem went away. The first two cars were not over 300rwhp around 4000rpms either( seeing 25/30psi). I've even seen a Tial 60mm overboost with bad runners!( only a single 2" length runner that was around 2.75" diameter).

I would disconnect the boost controller, and run just WG spring pressure to make sure its not a boost controller issue. I assumed you were not using a boost controller before these posts....

 

before doing all that runner work, i'd take the wastegate off and bolt on a pipe that exits somewhere to the side/back.
then take it for a run.
if it's a runner issue/restriction, wouldn't it still creep?

 

That wont help in the long run. No WG even a 50mm or a 60mm will not flow as much as a open pipe end with no restriction. WG's themselves will always generate some flow restriction

 

Well dropped the car off down at my mechanic so can hopefully get all this over boosted sorted.
Gone a bit of an over the top solution, but should be fine.

I bought another Tail 44 off gumtree ($200 !) guy didnt really know what it was :P

Went for a bit of a thrash last night to see if it did it all on the road and it does. 100 km is a bit under 4000 rpm (nearly full boost in 4th starting from about 3500 rpm) then at about 6000 rpm it start to creep.

so will see is this fix's it. (******* better !) dont know many setup thats need dual Tial 44mm's.

Othersie **** it will run 28psi on E85 :P

 

Awesome build !

 

i'm not one of those guys that likes the wide body panels and wings and such, but i'm also not one to **** in your chocolate just because i can. i really like the way the car turned out - the color is bad-***! i even like the "peeling metal" graphics (though not really a fan of the trails). overall i think your car is really nice.

i hope you get the wastegate/boost issues worked out soon and are able to start enjoying this thing the way it was meant to be enjoyed. good luck.

 

Good choice! You won't be disappointed.