When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
[QUOTEI think the issue is more related to the 8-900C heat cycles they are subjected to. I'm hoping that retorquing them after several cycles will do the trick.[/QUOTE]
I’m assuming you’re talking about exhaust stream temperatures. If so, your fasteners are probably somewhat cooler but likely still in the range where most automotive materials will creep. Changing to fasteners made from an aerospace alloy like inconel 718 might solve this. Otherwise, I wouldn’t do too many re-torque cycles on them before swapping out for new ones as they will eventually break.
[QUOTEI think the issue is more related to the 8-900C heat cycles they are subjected to. I'm hoping that retorquing them after several cycles will do the trick.
I’m assuming you’re talking about exhaust stream temperatures. If so, your fasteners are probably somewhat cooler but likely still in the range where most automotive materials will creep. Changing to fasteners made from an aerospace alloy like inconel 718 might solve this. Otherwise, I wouldn’t do too many re-torque cycles on them before swapping out for new ones as they will eventually break.[/QUOTE]
thats also what I meant writing above having them plactically deformed from heat
Before anyone gets too excited about the new Gen11 G series G30-725 for the Renesis, I just want to point out that it is in fact ... NOT an improvement on the original G30-660 ... for the Renesis.
Take a look at the overlay of the two compressors and the flow maps below and you'll see for pretty much every point on the flow map below PR 2.5 ..... the 660 is more efficient. No Renesis with this turbo ever goes over 2.5PR ! Above that range it's a definite improvement , which will be great for piston engines running over 20psi up to around 2.5L but not for a 13B rotary.
My first roll racing day yesterday with the Haltec PNP ECU + water/methanol injection. Still at a very conservative 10psi but hanging with and beating most of the competition on the day.
Videos :
Had a pretty good day but only another 8 cars entered. Did 15-20 roll races all up so raced most more than once.
At only 10psi the 8 was very competitive. I ended up 3rd but could actually have won it if not for some niggles with errant rev cuts. I need to add a button to force the w/m to put a squirt in just before the race after it's been sitting for several mins. I have a safety on IATs that cuts boost if they are too high.
I had to wait several mins before one of my elimination races and that safety cut boost at the start. This was against the Audi (which I'd previously beaten) and he ended up taking the win by a bumper- damnit!
Nice results Brett,
as to racing, its most of the time that you first need to win against your self, before you can win against others :D
are you injecting pure water or a mixture ?
As an alternative to boost cut for high iat, I found adding more fuel - dropping the target by 0.1 lambda and few deg on ignition was sufficient to combat any issue with some reduction in power obviously. (not on rx8 !, ie not tested so far). Where do you have fitted your IAT ? as it could be getting fake reading from hot intake manifold (by radiation) and very little cooling from intake air with low mass to cool it.
Nice results Brett,
as to racing, its most of the time that you first need to win against your self, before you can win against others :D
are you injecting pure water or a mixture ?
As an alternative to boost cut for high iat, I found adding more fuel - dropping the target by 0.1 lambda and few deg on ignition was sufficient to combat any issue with some reduction in power obviously. (not on rx8 !, ie not tested so far). Where do you have fitted your IAT ? as it could be getting fake reading from hot intake manifold (by radiation) and very little cooling from intake air with low mass to cool it.
It's 60:40 w/m ATM .. more water because reservoir is in engine bay and ...you know ...fires and stuff
Sensor is on one of the large main runners just after the point where it splits out to go to either rotor. Which is where it needed to be due to my nozzle placement. And yes, it's getting a 'fake' high reading which is why I thought a quick squirt would be the solution.
I need to add a button to force the w/m to put a squirt in just before the race after it's been sitting for several mins.
After messing with the Snow w/m controller ..... I just found that it actually has that function built in ! WOOT! Push the button and it squirts for a few seconds which is enough to bring IATs down a good 10C-15C ...perfect! I do need to rev the engine a little though as it wants to stall at idle.
Strange that there is no mention of this in the instructions!
Did some more roll racing at 'street to track' Hampton downs today. In the eliminations I ended up coming 3rd equal overall. Beaten only once by a 1000hp Supercharged LS3, and by only one car length! Was a very short track which really suited my fast spooling setup. Not bad for a Renesis! LOTs of people were surprised how competitive it was. Other cars raced on the day Nissan Cefiro below, Holden Clubsport V8 SS, late model BMW M3 , Toyota Supra late model. A couple more hot hatches.
Today was hot (25C) and car sat in line for a long time between races so was getting a lot of heat soak. Boost was at 12.5psi and I used my w/m '5s spray' button for first time to great effect! Also made use of the Haltec boost by gear tables to limit boost in 1st which worked well. Still experienced issues with lower boost during the day caused by heat soaked WG (I think)
Went to another roll racing event at Meremere dragway yesterday. This event was HUGE, I think this pic shows about 1/3 of the cars that were there! My red RX8 is 3rd lane over, four cars back.
Standard of cars was much higher than the previous event and while I didn't get a win (except when the other guy fd up), Red certainly was competitive. The longer course (full 1/4 mile) suited the more powerful cars.
Interestingly the final of the 2wd turbo comp I was in, was between the 1000whp supercharged holden commodore I raced at my last event and a Mazda 808 wagon running a 13b. The Mazda took it out!
The N/A class was won by another 808 wagon running a 20B PP vs another v8 monster.
So rotaries won the Day!
Amazing to see these lightweight rotaries deal to all and sundry!
Just thought to look at knock as recorded by Haltec. High according to Haltec is over 25. To my untrained eye all looks fine and W/M is doing it's job but don't really have anything to compare to. Looking at the log after throttle is let off it looks much the same as below, so must be ok.
Log is 2nd,3rd and some of 4th to 6700rpm.
Also: note how quick the spoolup is .... def. an advantage when ploughing through the gears.
My knock values are always through the roof. I have no idea. I think it's picking up minor reading or at least that's what I tell myself. My car is only half tuned by the way that may have something to do with it as well.
You are building boost very fast. Must be a little crazy to drive.
Last edited by Warrior777; Apr 28, 2026 at 09:51 AM.
My knock values are always through the roof. I have no idea. I think it's picking up minor reading or at least that's what I tell myself. My car is only half tuned by the way that may have something to do with it as well.
You are building boost very fast. Must be a little crazy to drive.
Thanks for the reply. Can you post a sample of what "through the roof" looks like?
I wouldn't say crazy to drive, just super responsive. The Haltec makes DBW throttle response very easy to tune so boost can be eased in with the throttle really precisely.
just the turbo side, unless I forgot about some other ones 
