Redline Time Attack/Super Lap Battle rebuild thread
Joined: Jun 2006
Posts: 29,085
Total Cats: 375
From: Republic of Dallas
Joined: Jun 2006
Posts: 29,085
Total Cats: 375
From: Republic of Dallas
He has the 1st-gen 1.8 intake plenum.
This makes me want to just pull my 2.0L and throw in an LS1 for the track car. These threads make me paranoid. Sorry to hear about this Andrew. At least it is good to see you motivated to get it fixed asap and get back out there. I would probably sulk a little.
Joined: Jun 2006
Posts: 29,085
Total Cats: 375
From: Republic of Dallas
can't do that without accusump.
https://www.miataturbo.net/forum/t41131/
+1 on the cylinder pressures making the engine riskier for detonation damage. Even at 7500 RPM, 300-400 RWHP out of a 1.8L 4-cyl takes a lot of cylinder pressure.
Sucks that the motor went, could of probly put up a faster hot lap time for Mod FR.
At least you have all the resources to get a motor put together and back in. Then you should have something for the competition
.
Sav, I think your motivation has sparked a lot of other motivation for everyone else. I've already tallied up cost of a v-band setup and on the short-term I've started to work on my 50 dollar motor so I can at least get my car running again.
Keep it going Sav, you give the miata community high hopes!
At least you have all the resources to get a motor put together and back in. Then you should have something for the competition
.Sav, I think your motivation has sparked a lot of other motivation for everyone else. I've already tallied up cost of a v-band setup and on the short-term I've started to work on my 50 dollar motor so I can at least get my car running again.
Keep it going Sav, you give the miata community high hopes!
Thread Starter
Joined: Nov 2006
Posts: 15,442
Total Cats: 2,106
From: Sunnyvale, CA
I'll probably step up to a 5 gallon/hr nozzle in the water, move it further back, and monitor AITs. Part of me thinks that a contributing factor here was the blown coupler Saturday, which skyrocketed the IATs all day and caused this detonation. We then cranked the boost up Sunday and lit the fuse I had laid the day before.
Joined: Jun 2006
Posts: 29,085
Total Cats: 375
From: Republic of Dallas
I put a piece of cardbaord over my FMIC when tuning and in one pull was able to make 230*f on one pull and the max the sensor will read id is 275*. I made a minor adjustment to the top end of my CLT/IAT "curve" to get AFR back in line and I assume that adjusted spark too. Time to start putting those little thermo-temp stickers on every heat exchanger (calipers, radiator, fmic, oil cooler, hood, brake reservoir, trans, rear-end, and who knows what I've overlooked.
I wonder how DIY determined what the IAT/CLT curve table should be?
Pull 1* every 1-2 degrees when MAP>atmo and IAT> 95F? 120?
beats me. I'd probably do something like 1° every 10*F above 140kPa when over 120*F AIT...something like that. Would need to see what AITs get to after a few laps, and where they get hot, ya know?
Joined: Jun 2006
Posts: 29,085
Total Cats: 375
From: Republic of Dallas
Here's what I've been running lately. Stock 95 long block at 18.4 psi from an intercooled whipple s/c on 93 octane.

I know that I'm running half a point more compression, and 7 less octane rating, but... It's as aggressive as I've been able to go. Any more and I get hints of detonation. I'd like my motor to live a little longer so that's where it stays. Once I get a built motor together, though I hope it takes the timing that you're using.
I know that the 6.2 degrees of advance I'm running at 220 kpa sounds unusual, but you've got to do whatever it takes to make sure that detonation is at bay. Cuz God knows we don't want to turn down the boost!
Also above about 190 kpa don't be afraid to go richer. Right now I'm aiming for about 10.8 AFRs, but I've gone as fat as 10.5 in rare surcumstances. Guys that are used to tuning N/A setups can be timid about going this rich just because, again it sounds unusual. But it's all about keeping the motor together.
Who's pistons are you using, and do you know the dish cc's?
Thanks for a great build thread! It's been a sweet read.






